Predictors of dysfunction and health-related quality of life in the flexion pattern subgroup of patients with chronic lower back pain

Findings about predictors of chronic lower-back pain (CLBP) were inconsistent and inconclusive in previous studies because patients with CLBP are heterogeneous. Subgrouping patients with CLBP, according to a CLBP classification system, might thus clarify the research findings. CLBP in the direction of lumbar flexion movement, that is, the flexion pattern, is common in clinical situations. Therefore, the purpose of this study was to determine the predictors of dysfunction (pain, disability) and health-related quality of life in the flexion pattern subgroup of patients with CLBP. A cross-sectional study of prospectively collected data. One hundred eight subjects in the flexion pattern subgroup of CLBP. Thirteen variables were measured: the visual analog scale (VAS), the Oswestry Disability Index (ODI), the Short Form-36 (SF-36), the Beck Depression Inventory (BDI), hip internal rotation range of motion, hip flexion range of motion, knee extension range of motion, knee extension with dorsiflexion range of motion, ratio forward flexion, knee extension strength, hip extension strength, hip flexion strength, and lumbopelvic stability. The models for predictors of lower-back pain in the CLBP flexion pattern subgroup included knee extension and the BDI as predictor variables that accounted for 8.1% of the variance in the VAS (P < .05); predictors for disability included the BDI, age, and hip flexion strength, which accounted for 21.2% of the variance in the ODI (P < .05); predictors for health-related quality of life included the BDI, sex, knee extension with dorsiflexion range of motion, and age, which accounted for 38.8% of the variance in the SF-36 (P < .05) in multiple regression models with a stepwise selection procedure. The current results suggest that knee extension, the BDI, age, hip flexion strength, knee extension with dorsiflexion, and sex should be considered when determining appropriate prediction, prevention, and intervention in the flexion pattern subgroup of patients with CLBP.

Related papers:

title: Diagnosis and classification of chronic low back pain disorders: maladaptive movement and motor control impairments as underlying mechanism.
abstract: Low back pain (LBP) is a very common but largely self-limiting condition. The problem arises however, when LBP disorders do not resolve beyond normal expected tissue healing time and become chronic. Eighty five percent of chronic low back pain (CLBP) disorders have no known diagnosis leading to a classification of 'non-specific CLBP' that leaves a diagnostic and management vacuum. Even when a specific radiological diagnosis is reached the underlying pain mechanism cannot always be assumed. It is now widely accepted that CLBP disorders are multi-factorial in nature. However the presence and dominance of the patho-anatomical, physical, neuro-physiological, psychological and social factors that can influence the disorder is different for each individual. Classification of CLBP pain disorders into sub-groups, based on the mechanism underlying the disorder, is considered critical to ensure appropriate management. It is proposed that three broad sub-groups of CLBP disorders exist. The first group of disorders present where underlying pathological processes drive the pain, and the patients' motor responses in the disorder are adaptive. A second group of disorders present where psychological and/or social factors represent the primary mechanism underlying the disorder that centrally drives pain, and where the patient's coping and motor control strategies are mal-adaptive in nature. Finally it is proposed that there is a large group of CLBP disorders where patients present with either movement impairments (characterized by pain avoidance behaviour) or control impairments (characterized by pain provocation behaviour). These pain disorders are predominantly mechanically induced and patients typically present with mal-adaptive primary physical and secondary cognitive compensations for their disorders that become a mechanism for ongoing pain. These subjects present either with an excess or deficit in spinal stability, which underlies their pain disorder. For this group, physiotherapy interventions that are specifically directed and classification based, have the potential to impact on both the physical and cognitive drivers of pain leading to resolution of the disorder. Two case studies highlight the different mechanisms involved in patients with movement and control impairment disorder outlining distinct treatment approaches involved for management. Although growing evidence exists to support this approach, further research is required to fully validate it.

title: Non-specific low back pain
abstract: Non-specific low back pain has become a major public health problem worldwide. The lifetime prevalence of low back pain is reported to be as high as 84%, and the prevalence of chronic low back pain is about 23%, with 11-12% of the population being disabled by low back pain. Mechanical factors, such as lifting and carrying, probably do not have a major pathogenic role, but genetic constitution is important. History taking and clinical examination are included in most diagnostic guidelines, but the use of clinical imaging for diagnosis should be restricted. The mechanism of action of many treatments is unclear, and effect sizes of most treatments are low. Both patient preferences and clinical evidence should be taken into account for pain management, but generally self-management, with appropriate support, is recommended and surgery and overtreatment should be avoided.

title: Does back pain prevalence really decrease with increasing age? A systematic review.
abstract: It is believed that the prevalence of back pain decreases around the middle of the sixth decade. However, back pain is still among the most commonly reported symptoms in the elderly and osteoarthritis, disc degeneration, osteoporosis and spinal stenosis all increase with age. In light of this, it is difficult to understand why the prevalence of back pain would decrease with increasing age.



This study aimed at summarising the scientific evidence on the trends of back pain prevalence with age.



Population-based studies reporting the prevalence of back pain, including people aged 65 years and over, were systematically retrieved from several bibliographic databases. These were read and assessed by two reviewers, and papers retained ('good quality studies') were aggregated according to specific criteria.



Good quality studies showed a large heterogeneity as to their methods and prevalence figures. No specific patterns were detected by country nor outcome measure. However, most studies that considered severe forms of back pain found an increase of prevalence with increasing age. The curvilinear association between age and back pain prevalence that is widely mentioned in the literature was found only for benign and mixed problems.



The evidence concerning the association of back pain prevalence with age is more sparse than currently believed and this association seems to be modified by the severity of the problem. This knowledge could have important public health implications, as the proportion of older people will increase considerably in the coming years in most industrialised societies.

title: Sex comparison of extensibility, passive, and active stiffness of the knee flexors.
abstract: To compare extensibility, and passive and active stiffness of the knee flexors between males and females.



An experimental design utilized 15 males and 15 females to identify sex differences in active extensibility, and active and passive stiffness of the knee flexors.



Muscle stiffness appears to contribute to joint stability from both mechanical and neuromuscular perspectives. Differences in knee flexor stiffness may partially explain higher female anterior cruciate ligament injury rates.



Active knee flexor extensibility was assessed as subjects extend the knee from a fixed hip position, measuring the final knee position. Passive knee flexor stiffness was calculated as the slope of the moment-angle curve resulting from controlled passive knee extension. Active knee flexor stiffness was assessed by loading the lower extremity with 10% total body mass, and measuring the damping effect of the knee flexors on imposed vibratory motion about the knee joint.



Females displayed greater active extensibility (P<0.05), while males displayed greater active (P<0.05) and passive (P<0.05) knee flexor stiffness. Sex differences in active and passive knee flexor stiffness were not significant following normalization to anthropometric characteristics.



The knee flexor musculature in males is less extensible and displays greater active and passive stiffness compared to females. However, these differences may be functions of greater mass and height in males.

title: Gender differences in active musculoskeletal stiffness. Part I. Quantification in controlled measurements of knee joint dynamics.
abstract: Active females demonstrate increased risk for musculoskeletal injuries relative to equivalently-trained males. Although gender differences in factors such as passive laxity, skeletal geometry and kinematics have been examined, the effect of gender on active muscle stiffness has not been reported. Stiffness of the active quadriceps and hamstrings musculature were recorded during isometric knee flexion and extension exertions from twelve male and eleven female subjects. A second-order biomechanical model of joint dynamics was used to quantify stiffness from the transient motion response to an angular perturbation of the lower-leg. Female subjects demonstrated reduced active stiffness relative to male subjects at all torque levels, with levels 56-73% of the males. Effective stiffness increased linearly with the torque load, with stiffness increasing at a rate of 3.3 Nm/rad per unit of knee moment in knee flexion exertions (hamstrings) and 6.6 Nm/rad per unit of knee moment extension exertions (quadriceps). To account for gender differences in applied moment associated with leg mass, regressions analyses were completed that demonstrated a gender difference in the slope of stiffness-versus-knee moment relation. Further research is necessary to identify the cause of the observed biomechanical difference and implications for controlling injury.

title: Relationship between the hip and low back pain in athletes who participate in rotation-related sports.
abstract: Hip function has been proposed to be related to low back pain (LBP) because of the anatomical proximity of the hip and lumbopelvic region. To date, findings have been inconclusive, possibly because the samples studied were heterogeneous. Sub-grouping samples based on characteristics such as activity demand, LBP classification, and sex might clarify research findings.



To describe and summarize studies that examine 3 factors proposed to be important to the study of the hip-LBP relationship.



Review of cross-sectional studies.



Academic health-care center and research laboratory.



3 groups: athletes with a history of LBP who regularly participate in rotation-related sports, athletes without a history of LBP who are active but do not regularly participate in rotation-related sports, and athletes without a history of LBP who participate in rotation-related sports.


MAIN OUTCOME
Hip range of motion and hip-lumbopelvic region coordination.



Hip range of motion was measured with an inclinometer. Coordination was examined based on kinematics obtained with a 3-dimensional motion-capture system.



Differences among groups were found based on activity demand, LBP classification, and sex.



When assessing athletes with and without LBP, characteristics such as activity demand, LBP classification, and sex should be considered.

title: Measurement of Muscle Strength of the Trunk and the Lower Extremities in Subjects With History of Low Back Pain
abstract: Study Design Isokinetically measured muscle strength of the trunk and lower extremities was analyzed.  The causes of the weak trunk muscle strength of subjects with low back pain were studied.  Although it is a commonly accepted conclusion that subjects with low back pain have weaker trunk muscles than the normal population, there are no reports concerning muscle strength of the lower extremities in subjects with low back pain.  Ninety-eight male volunteers were divided into control groups and groups with low back pain. The total trunk strength and total knee strength were defined as the sum of the peak torques of trunk extension, flexion and rotation, and of bilateral knee extension and flexion, respectively.  The total trunk and knee strength in the group with low back pain (281 ± 170 and 301 ± 132 Nm) were significantly lower than in the control group (543 ± 124 and 441 ± 123 Nm). The total trunk and knee strength were linearly correlated in both groups (r=0.67 and 0.79).  In the group with low back pain, the muscles of the trunk and the lower extremities were similarly affected; this can be attributed to generalized muscular weakness or psychologic factors, such as fear of injury.

title: Relationship between mechanical factors and incidence of low back pain.
abstract: A multifactorial cross-sectional nonexperimental design.



To collectively investigate the association among 17 mechanical factors and occurrence of low back pain (LBP).



Several physical characteristics, based on assumptions, clinical findings, and scientific experiments, have been associated with the development of LBP Controversy exists regarding the degree of association between some of these physical characteristics and LBP. Information regarding the degree of association of each factor to LBP is needed for effective prevention and appropriate treatment strategies.



A total of 600 subjects participated in this study. Subjects were categorized into 4 groups: asymptomatic men (n = 150, age [mean +/- SD] = 43 +/- 15 years), asymptomatic women (n = 150, age [mean +/- SD] = 43 +/- 13 years), men with LBP (n = 150, age [mean +/- SD] = 43 +/- 14 years), and women with LBP (n = 150, age [mean +/- SD] = 43 +/- 13 years). Seventeen physical characteristics were measured in each group and the relative association of each characteristic with LBP was assessed.



Among all the factors tested, endurance of the back extensor muscles had the highest association with LBP Other factors such as the length of the back extensor muscles, and the strength of the hip flexor, hip adductor, and abdominal muscles also had a significant association with LBP.



It appears that muscle endurance and weakness are associated with LBP and that structural factors such as the size of the lumbar lordosis, pelvic tilt, leg length discrepancy, and the length of abdominal, hamstring, and iliopsoas muscles are not associated with the occurrence of LBP.

title: Intra-abdominal pressure and trunk muscle activity during lifting. II. Chronic low-back patients.
abstract: The aim of this study was to compare trunk muscle strength and intra-abdominal pressure during lifting in low-back patients and in healthy controls. Twenty male workers with 2-18 year history (median 5.5 years) of low-back pain went through strength tests of trunk flexion and extension and a series of standardized lifts. The intra-abdominal pressure (IAP) and the EMG activity of the oblique abdominal muscles and of the erector spinae muscles were recorded. The results were compared with those in 20 healthy men exposed to similar loads at work and at leisure. The low-back patients had reduced abdominal muscle strength (-25%) compared with the healthy controls. The IAP during lifting was the same in the two groups despite the difference in abdominal muscle strength. The trunk extension strength was the same in the two groups. The oblique abdominal muscles were only moderately activated during lifting (5-15% of maximum activity with 25 kg) both in low-back patients and in healthy controls. The erector spinae muscle was strongly activated during lifting (40-60% of maximum activity with 25 kg) both in low-back patients and in healthy controls. During backlifting the duration of erector spinae activity varied. Back patients had extended activity compared with the healthy controls. Stiffness seemed to affect the duration of activity in both groups. The oblique abdominal muscles seem to be of no decisive importance to the IAP.

title: Strength and Flexibility Characteristics of Athletes with Chronic Low-Back Pain
abstract: The purpose of this study was to identify strength and flexibility deficits in subjects with chronic low-back pain (CLBP). Subjects were 16 female Division I athletes: 8 athletes who had experienced CLBP for at least 6 months prior to testing and a control group of 8 matched subjects. Athletes with neurological symptoms, previous back operations, and leg length discrepancies and those who were diagnosed with scoliosis, spondylolisthesis, or spondylolysis were excluded from this study. Variables assessed included abdominal strength, erector spinae endurance, hip flexion and extension endurance, torso lateral flexibility, and low-back flexibility. Strength and endurance were calculated as a function of time in seconds. Goniometric measurements were used to determine flexibility. Significant mean differences were found by using dependent t tests for abdominal strength, erector Spinae endurance, hip extension, and right lateral flexion of the torso. The results validate the necessity for pelvic stabilization ...

title: Endurance of trunk muscles in persons with chronic low back pain: assessment, performance, training.
abstract: Trunk muscles are designed to fulfill their role of continuous activity throughout the day, but pain and inactivity alter muscles so that they fatigue in normal situations. Lack of endurance of the trunk muscles is an important factor in low back pain (LBP). This paper examines some methods to objectively test endurance of trunk flexor and extensor muscles in static and dynamic situations, and presents results of endurance testing in persons with chronic LBP compared to nonimpaired cohorts. Self perception of fitness affects some test results. Methods for increasing endurance are discussed along with benefits observed from training programs.

title: Back and hip extensor activities during trunk flexion/extension: effects of low back pain and rehabilitation.
abstract: To compare lumbar paraspinal, gluteus maximus, and biceps femoris muscle function during sagittal trunk flexion and extension in patients with chronic low back pain and healthy control subjects, and to assess the influence of rehabilitation in the back pain patients.



A cross-sectional study comparing chronic low back pain patients and healthy controls, and a prospective follow-up in back pain patients during rehabilitation.



Physical medicine and rehabilitation clinic.



Nineteen women with chronic low back pain, and 19 women without pain (controls).



Five-week active outpatient rehabilitation (1 hour three times a week) guided by a physiotherapist, followed by 5-week self-motivated exercise at home.



Subjects performed sagittal trunk flexion and extension while surface electromyogram was bilaterally recorded of paraspinal (L1-L2 level), gluteus maximus, and biceps femoris muscles. The muscle activity was assessed from the average electromyogram and the relative muscle activation onsets and their duration were calculated.



During early flexion, lumbar paraspinal and biceps femoris were activated simultaneously before gluteus maximus. At the end of flexion and during extension all investigated muscles were activated and relaxed in order. Lumbar paraspinal and biceps femoris muscles were activated in a similar order in low back pain patients and healthy controls during flexion and extension. However, the duration of gluteus maximus activity was shorter in the back pain patients than in controls during the trunk flexion (p<.05), and it ended earlier during extension. Active rehabilitation did not change the muscle activities of lumbar paraspinal and biceps femoris in the back pain patients, but in the measurements after rehabilitation the onset of gluteus maximus activity occurred later in flexion and earlier in extension.



The activity of the gluteus maximus muscle during the flexion-extension cycle was reduced in patients with chronic low back pain. The gluteal muscles should be taken into consideration in the rehabilitation of these patients.

title: Delayed postural contraction of transversus abdominis in low back pain associated with movement of the lower limb.
abstract: The temporal parameters of the response of the trunk muscles associated with movement of the lower limb were investigated in people with and without low back pain (LBP). The weight shift component of the task was completed voluntarily prior to a stimulus to move to allow investigation of the movement component of the response. In the control subjects the onset of electromyographic (EMG) activity of all trunk muscles preceded that of the muscle responsible for limb movement, thus contributing to the feed-forward postural response. The EMG onset of transversus abdominis was delayed in the LBP subjects with movement in each direction, while the EMG onsets of rectus abdominis, erector spinae, and oblique abdominal muscles were delayed with specific movement directions. This result provides evidence of a change in the postural control of the trunk in people with LBP.

title: Decreased joint and spinal mobility associated with low back pain in young adults.
abstract: Anthropometric factors, spinal and limb-joint mobility, and trunk strength were measured in young students--55 men and 48 women (mean age 21.4 years, SD 1.6). Twenty-six of the men and 29 of the women had had back pain during the preceding year and they were compared with those without back pain. In the male back-pain group, extension, lateral flexion and the sum of mobility in the lumbar spine, and hip flexion and external rotation of the shoulders were significantly smaller. In the female back-pain group, extension and the sum of mobility in the thoracic spine, and extension, external rotation, and the sum of mobility in the hips were significantly diminished. Anthropometric factors and trunk strength had no significant relationship with a history of back pain except for a pronounced lordosis in women. The results suggest that ligamentous or capsular stiffness of the joints may be associated with low back pain in young adults.

title: Correlations of hip mobility with degree of back pain and lumbar spinal mobility in chronic low-back pain patients.
abstract: Mobility of hips and lumbar spine were measured in 301 men and 175 women who were in employment but suffered from chronic or recurrent low-back pain. The degree of low-back pain (LBP) was assessed with a questionnaire. Hip flexion, extension, internal rotation, and hamstring flexibility in the men, and hip flexion and extension in the women had statistically significant negative correlations with LBP. Among the correlations between hip and lumbar spinal mobility, hip flexion and extension with lumbar rotation were strongest.

title: Lumbopelvic motion during seated hip flexion in subjects with low-back pain accompanying limited hip flexion
abstract: PurposeLimited hip flexion may lead to a poor lumbopelvic motion during seated active hip flexion in people with low-back pain (LBP). The purpose of this study was to compare lumbopelvic motion during seated hip flexion between subjects with and without LBP accompanying limited hip flexion.MethodsFifteen patients with LBP accompanying limited hip flexion and 16 healthy subjects were recruited. The subjects performed seated hip flexion with the dominant leg three times. A three-dimensional motion-analysis system was used to measure lumbopelvic motion during seated hip flexion.ResultsDuring seated active hip flexion, the angle of hip flexion was significantly lower in patients with LBP accompanying limited hip flexion (17.4 ± 4.4 in the LBP group, 20.8 ± 2.6 in the healthy group; t = 2.63, p = 0.014). The angle of the lumbar flexion (4.8 ± 2.2 in the LBP group, 2.6 ± 2.0 in the healthy group; t = −2.96, p = 0.006) and posterior pelvic tilting (5.0 ± 2.6 in the LBP group, 2.9 ± 2.0 in the healthy group; t = 2.48 p = 0.019), however, were significantly greater in patients with this condition.ConclusionsThe results of this study suggest that limited hip flexion in LBP can contribute to excessive lumbar flexion and posterior pelvic tilting during hip flexion in the sitting position. Further studies are required to confirm whether improving the hip flexion range of motion can reduce excessive lumbar flexion in patients with LBP accompanying limited hip flexion.

title: Trunk muscle function and low back disorders: a ten-year follow-up study.
abstract: Low back disorders and trunk muscle function were studied by questionnaire, interview, clinical examination, and performance tests in 902 employees in the metal industry. The survey was repeated after a 10-yr interval for 654 persons. For those who were allowed to participate in the muscle function tests, the prevalences of clinical findings in the low back and of chronic lumbosacral disease were inversely associated with muscle function in both cross-sectional studies. This association seems not to be explained by the interference of pain with muscle function tests. There was no association between muscle function at baseline and either the 10-yr incidence of chronic low back disease or the development of low back symptoms. Men with poor muscle function at baseline had a slightly elevated risk for the appearance of clinical findings at follow-up. There was an inverse association between the clinical findings at baseline and muscle function at follow-up. The association between low back disorder and trunk muscle function seems to result from an effect of the former on the latter, but poor muscle function may also contribute to the risk of disorder.

title: Concentric and eccentric strength of trunk muscles: influence of test postures on strength and characteristics of patients with chronic low-back pain.
abstract: The purpose of this study was to determine the influence of test postures on trunk muscle strength, and to clarify the difference between concentric and eccentric strength of healthy subjects and patients with chronic low-back pain (CLBP). Volunteered and controlled trials took place at a university hospital, which is a referral center and is also open to the general community. The patients were selected from the outpatient care in the university hospital. Fifty healthy subjects (25 men and 25 women; average age 25.7 years, ranging from 23 to 34 years) and 48 patients with CLBP (26 men and 22 women; average age 33.5 years, ranging from 26 to 39 years) volunteered for this study. The main outcome measures were flexor and extensor peak torque/body weight, and flexor/extensor peak torque ratio during concentric and eccentric contractions; Eccentric/concentric peak torque ratio in flexor and extensor. Trunk-muscle strength was significantly greater in the sitting posture when measured with the subjects' feet against the floor (p < .05). Some patients complained of a slight low-back pain during testing, although the pain was not aggravated in any patients. In both concentric and eccentric contraction modes, the patients with CLBP had greater flexor/extensor ratios than the healthy subjects (p < .01). This implies that extensors are more affected in these patients. However, a great imbalance between concentric and eccentric strength of the patients was found, not only in extensors, but also in flexors (p < .01). The current study shows that one should consider the test posture carefully when measuring trunk-muscle strength.(ABSTRACT TRUNCATED AT 250 WORDS)

title: Tightness of hamstring- and psoas major muscles. A prospective study of back pain in young men during their military service.
abstract: Muscular tightness and the therapeutic effect of stretching has been widely discussed during the last few years in sports training and physiotherapy. Within a prospective study of back function and pain before and after compulsory military service, tightness of hamstring- and psoas muscles was assessed. Around 600 young men were examined three times over a period of four years. Tight hamstring muscles were found to be very common in this group. Only 43% of the right and 35% of the left legs reached an angle of at least 80 degrees from the couch during the straight-leg-raising test (Lasegue's test). The test of muscular tightness showed a significant test-retest reliability over all examinations. Tight hamstring- or psoas muscles could not be shown to correlate to current back pain or to the incidence of back pain during the follow-up period.

title: The Inter‐Tester Reliability of Physical Therapists Classifying Low Back Pain Problems Based on the Movement System Impairment Classification System
abstract: The classification of patients with low back pain (LBP) may be important for improving clinical outcomes and research efficiency. The purpose of this study was to examine the inter‐tester reliability of 2 trained physical therapists to classify patients with LBP by using the standardized Movement System Impairment (MSI) classification system. The 5 proposed MSI classifications are based on the most consistent patterns of movement and alignment observed throughout the examination that correlate with the patient's symptom behavior.

title: Classification, treatment and outcomes of a patient with lumbar extension syndrome
abstract: The purpose of the current report is to describe the classification, treatment, and outcomes of a patient with lumbar extension syndrome. The patient was a 40-year-old female with an 18-month history of mechanical low back pain (LBP). The patient reported a history of daily, intermittent pain (mean intensity of 9/10) that limited her ability to sit, stand, walk, and sleep, as well as perform work-related activities. Symptom-provoking movement and alignment impairments associated with the direction of lumbar extension were identified and modification of these impairments consistently resulted in a decrease in pain. Treatment was provided in 3 sessions over a 2-month period. Priority of treatment was to train the patient to restrict lumbar extension-related alignments and movements during symptom-provoking functional activities. Exercises to address the extension-related impairments also were prescribed. The primary change in outcome was a decrease in the mean intensity (2 months: 2/10; 6 months: 1/10) and frequency of pain (2 months: decreased pain with standing and walking; 6 months: additional decrease with sitting, standing and walking). She also reported a decreased duration and number of LBP episodes. Classification directed treatment resulted in improvement in short and long term impairment and functional-level outcomes.

title: Diagnosis and Treatment of Movement Impairment Syndromes
abstract: Chapter 2: Concepts and Principles of Movement System Balance Chapter 3: Imbalances of the Trunk and Low Back Movement Impairment Syndromes Chapter 4: Lower Extremity Imbalances and Hip Impairment Syndromes Chapter 5: Upper Extremity Imbalances and Shoulder Impairment Syndromes Chapter 6: Examination for Muscle and Movement Imbalances for the Lower Quarter, the Trunk, and the Shoulder Girdle Chapter 7: Exercise Descriptions for the Practitioner Chapter 8: Exercise Handouts for the Patient Chapter 9: Case Studies

title: Reliability of physical examination items used for classification of patients with low back pain.
abstract: The purpose of this study was to examine the interrater reliability of measurements obtained by examiners administering tests proposed to be important for classifying low back pain (LBP) problems.



Ninety-five subjects with LBP (41 men, 54 women) and 43 subjects without LBP (17 men, 26 women) were examined by 5 therapists trained in the techniques used.



A manual was developed by the first author that described the clinical examination procedures. The therapists were trained by the first author in the test procedures and definitions. The training included instruction through videotapes, practice and a written examination. Each examination was conducted by a pair of therapists. Within a pair, a therapist was the primary examiner for half of the subjects and an observer was the primary examiner for half of the subjects. Examination findings were recorded independently, without discussion.



Percentage of agreement and generalized kappa coefficients were used to analyzed the data. Kappa values were > or = .75 for all 28 items related to the symptoms elicited and > or = .40 for 72% of the 25 items related to alignment and movement.



The results suggest that experienced therapist who had trained together were able to agree on the results of examinations and obtain an acceptable level of reliability. Future work should focus on testing of reliability when more than one therapist performs the examination and when therapist not trained by the test developer to administer the examination perform the tests. [Van Dillen LR, Sahrmann SA, Norton BJ, et al. Reliability of physical examination items used for classification of patients with low back pain.

title: Classification, intervention, and outcomes for a person with lumbar rotation with flexion syndrome.
abstract: The purpose of this case report is to describe the classification, intervention, and outcomes for a patient with lumbar rotation with flexion syndrome.



The patient was a 22-year-old man with a medical diagnosis of low back strain. Impairments in lumbar flexion and right rotation and lateral bending were identified. Daily activities and positions associated with these actions were associated with increased low back pain (LBP). Instruction focused on modifying lumbar rotation and flexion movements and alignments in daily activities. Exercises to address the direction-specific impairments were prescribed.



The patient participated in 4 visits and completed a questionnaire 1 year after intervention. The patient reported a decrease in symptoms, disability, and frequency of recurrences.



Repetition of specific strategies (alignment and movement) during activities may result in specific impairments that contribute to LBP. Modification of the strategies and exercises to change contributing factors are proposed to help alleviate symptoms, disability, and recurrences.

title: Inter-tester reliability of a new diagnostic classification system for patients with non-specific low back pain.
abstract: Most patients referred to physiotherapy with low back pain are without a precise medical diagnosis. Identification of subgroups of non-specific low back pain patients may improve clinical outcomes and research efficiency. A pathoanatomic classification system has been developed, classifying patients with non-specific low back pain into 12 different syndromes and three subcategories based on history and physical examination. The purpose of this study was to estimate the inter-tester reliability of clinical tests used as criteria for classifying patients. Ninety patients with chronic low back pain were each examined by two physiotherapists. A total of four physiotherapists conducted the assessments. Examination findings were recorded independently by the two examiners. Percentage of agreement and kappa coefficients were calculated for each category. The overall rate of agreement was 72% and the kappa coefficient was 0.62 for the mutually exclusive syndromes in the classification system. Agreement rates for each of the syndromes ranged from 74% to 100% and kappa coefficients ranged from 0.44 to 1.00. The findings suggest the inter-tester reliability of the system is acceptable. The relatively modest level of total agreement (39%) for the system as a whole might indicate that the utility of the system for general screening purposes is limited, compared with the utility in identification of particular syndromes. Due to low prevalence of positive findings in some of the syndromes, future work should focus on testing reliability on a larger sample of patients, and testing of validity and feasibility of the system.

title: Lumbar segmental 'instability': clinical presentation and specific stabilizing exercise management.
abstract: Lumbar segmental instability is considered to represent a significant sub-group within the chronic low back pain population. This condition has a unique clinical presentation that displays its symptoms and movement dysfunction within the neutral zone of the motion segment. The loosening of the motion segment secondary to injury and associated dysfunction of the local muscle system renders it biomechanically vulnerable in the neutral zone. The clinical diagnosis of this chronic low back pain condition is based on the report of pain and the observation of movement dysfunction within the neutral zone and the associated finding of excessive intervertebral motion at the symptomatic level. Four different clinical patterns are described based on the directional nature of the injury and the manifestation of the patient's symptoms and motor dysfunction. A specific stabilizing exercise intervention based on a motor learning model is proposed and evidence for the efficacy of the approach provided.

title: The self-reported aggravating activities of people with chronic non-specific low back pain do not involve consistent directions of spinal movement: an observational study.
abstract: Do the self-reported aggravating activities of people with chronic non-specific low back pain move the spine in a consistent direction?



Cross-sectional observational study.



240 people with chronic non-specific low back pain.


OUTCOME MEASURE
The self-reported aggravating activities from the Patient Specific Functional Scale were classified as flexion, extension or unilateral according to the direction of lumbar spine movement. PARTICIPANTS were described as demonstrating a directional pattern if all three self-reported aggravating activities moved the spine in the same direction.



Of the 148 participants with three classifiable aggravating activities, 47 (32%) demonstrated a directional pattern with 46 (98%) demonstrating a flexion pattern and 1 (2%) an extension pattern. The observed incidence of a directional pattern in the three self-reported aggravating activities of the 148 participants (32%) was no different from what would have been expected by chance. There were no clinical or demographic differences between those who demonstrated a directional pattern and those who did not.



There is no evidence for the existence of a consistent direction of spinal movement during the self-reported aggravating activities of people with chronic non-specific low back pain.

title: Bispectral Index Monitoring during Anesthesiologist-Directed Propofol and Remifentanil Sedation for Endoscopic Submucosal Dissection: A Prospective Randomized Controlled Trial
abstract: Endoscopic submucosal dissection (ESD) is a technically difficult and lengthy procedure requiring optimal depth of sedation. The bispectral index (BIS) monitor is a non-invasive tool that objectively evaluates the depth of sedation. The purpose of this prospective randomized controlled trial was to evaluate whether BIS guided sedation with propofol and remifentanil could reduce the number of patients requiring rescue propofol, and thus reduce the incidence of sedation- and/or procedure-related complications.  A total of 180 patients who underwent the ESD procedure for gastric adenoma or early gastric cancer were randomized to two groups. The control group (n=90) was monitored by the Modified Observer's Assessment of Alertness and Sedation scale and the BIS group (n=90) was monitored using BIS. The total doses of propofol and remifentanil, the need for rescue propofol, and the rates of complications were recorded.  The number of patients who needed rescue propofol during the procedure was significantly higher in the control group than the BIS group (47.8% vs. 30.0%, p=0.014). There were no significant differences in the incidence of sedation- and/or procedure-related complications.  BIS-guided propofol infusion combined with remifentanil reduced the number of patients requiring rescue propofol in ESD procedures. However, this finding did not lead to clinical benefits and thus BIS monitoring is of limited use during anesthesiologist-directed sedation.

title: Pain measurement tools for clinical practice and research.
abstract: An important component of effective postoperative pain management is a measure of the patient's pain intensity. This article examines three unidimensional pain measurement instruments and one multidimensional pain measurement instrument used in daily practice and clinical research. The strengths and weaknesses of the numerical rating scale, verbal descriptor scale, visual analogue scale, and the McGill Pain Questionnaire are discussed. Issues of validity and reliability, important in clinical research, are also presented.

title: Measuring patients' views: the optimum outcome measure.
abstract: quarter of ambulance crews in London are paramedics, but analysis of workload suggests that less than one tenth of calls require paramedical skills. The London Ambulance Service already trains more paramedics than any other service in Britain and loses some of them to provincial services after training. Only one third of hospitals served by the London Ambulance Service provide clinical training placements for paramedics, and even to meet current needs this will require a substantial increase. To achieve the Department of Health's target will require a substantial increase in training at considerable cost. Is this likely to be economic? How will most paramedics maintain their skills when only a small proportion of calls require them?'0 Will the damage to the morale of staff who are not paramedics, seen in other services with the development of an elite, occur in London? The London Ambulance Service has avoided many of these problems by ensuring that some extended skills, such as provision of defibrillation and nebuliser treatment, are taught to every qualified ambulance person. Evidence also exists that ambulance staff who are not paramedics can safely identify and treat hypoglycaemia with glucagon." If implementing a dispatch system responsive to medical priority shows that resources are being effectively targeted according to clinical need the aim of having a paramedic in every front line vehicle would need to be reconsidered. Historically, informal links with individual clinicians and specialty groups have facilitated many changes in ambulance training, operations, and equipment. As the range and complexity of prehospital care increases, however, the mechanisms for medical input to the London Ambulance Service and the audit ofoutcomes will need review. Currently, there is official medical input to extended training in the form of the paramedic steering committee as required by the NHS Training Directorate, but in other matters of policy the only other medical forum, the medical advisory group, has no operational responsibilities. Recent initiatives that have required close liaison are the development of joint training for ambulance and medical incident officers in the management of major incidents,'2 proposals for increasing direct communication between ambulances and accident and emergency departments, and the development of alternatives to obstetric flying squads.'3 The input of the medical advisory group to long term planning and development would be valuable. Unified medical input and systematic audit'4 are particularly necessary in view of the differing medical opinions and prejudices regarding the philosophies of "scoop and run" versus "treat in the street." How best to coordinate medical advice for the London Ambulance Service should be a matter for debate. In particular, the potential benefit to London of the consultant medical director model-popular in the United States and currently being pioneered in the Scottish Ambulance Service-will need careful assessment. Public interest in the London Ambulance Service is obvious, but public confidence, shaken by the 1989 ambulance strike and by the problems of last year, needs to be restored. Although response times have the highest profile-being easily measured-the quality of clinical care delivered is also crucially important, and its absence from the topics included in the service's annual corporate review is regrettable.15 The London Ambulance Service's new management must make an unequivocal commitment to both basic and extended training and the establishment of systematic clinical audit to build on the progress made to date. As a consumer, the public has a part to play in making the service more efficient, and a health education campaign supported by the government is long overdue. Management commitment is likely to produce better response times over the next three years, but this will be a hollow achievement without advances in clinical care.

title: An inventory for measuring depression.
abstract: The difficulties inherent in obtaining consistent and adequate diagnoses for the purposes of research and therapy have been pointed out by a number of authors. Pasamanick12in a recent article viewed the low interclinician agreement on diagnosis as an indictment of the present state of psychiatry and called for "the development of objective, measurable and verifiable criteria of classification based not on personal or parochial considerations, but on behavioral and other objectively measurable manifestations." Attempts by other investigators to subject clinical observations and judgments to objective measurement have resulted in a wide variety of psychiatric rating scales.4,15These have been well summarized in a review article by Lorr11on "Rating Scales and Check Lists for the Evaluation of Psychopathology." In the area of psychological testing, a variety of paper-and-pencil tests have been devised for the purpose of measuring specific

title: Hip rotation range of motion in sitting and prone positions in healthy Japanese adults
abstract: The aim of this study was to elucidate the difference in hip external and internal rotation ranges of motion (ROM) between the prone and sitting positions.  The subjects included 151 students.  Hip rotational ROM was measured with the subjects in the prone and sitting positions. Two-way repeated measures analysis of variance (ANOVA) was used to analyze ipsilateral hip rotation ROM in the prone and sitting positions in males and females. The total ipsilateral hip rotation ROM was calculated by adding the measured values for external and internal rotations.  Ipsilateral hip rotation ROM revealed significant differences between two positions for both left and right internal and external rotations. Hip rotation ROM was significantly higher in the prone position than in the sitting position. Hip rotation ROM significantly differed between the men and women. Hip external rotation ROM was significantly higher in both positions in men; conversely, hip internal rotation ROM was significantly higher in both positions in women.  Hip rotation ROM significantly differed between the sexes and between the sitting and prone positions. Total ipsilateral hip rotation ROM, total angle of external rotation, and total angle of internal rotation of the left and right hips greatly varied, suggesting that hip joint rotational ROM is widely distributed.

title: Factors associated with increased propensity for hamstring injury in English Premier League soccer players.
abstract: The aim of this study was to concurrently model the influence of a number of physical and performance parameters on subsequent incidence of hamstring injury in a squad of English Premier League soccer players. Thirty six healthy, male, elite, professional soccer players (age 22.6+/-5.2 years, height 1.81+/-0.08 m, mass 75.8+/-9.4 kg, lean mass 69.0+/-8.0 kg) were assessed during the first week of pre-season training for anthropometry, flexibility, lower limb strength and power, speed and agility. Over the subsequent 45 week competitive season all hamstring injuries were diagnosed and recorded. Multiple logistic regression analysis was performed to link individual physical and performance capabilities with propensity to sustain a hamstring injury. A model containing age, lean mass, non-counter movement jump (NCM) performance and active hip flexion range of movement (ROM) was significantly (p<0.05) associated with increased propensity for hamstring injury. Odds for sustaining an injury increased x 1.78 for each 1 year increase in age, x 1.47 for each 1cm increase in NCM and x 1.29 for each 1 degrees decrease in active range of hip flexion. Older, more powerful and less flexible soccer players are at greater risk of sustaining a hamstring injury. Support staff should identify such individuals and make appropriate interventions to minimise risk without compromising performance capabilities.

title: Effects of ankle dorsiflexion on active and passive unilateral straight leg raising.
abstract: The purpose of this study was to analyze the straight-leg-raising (SLR) maneuver while the ankle was fixed in dorsiflexion or relaxed in plantar flexion. Twenty-two healthy subjects underwent active and passive SLR with the ankle in each position. We used cinematography to document movement of the right lower limb and pelvis and electromyography to document hamstring muscle activity. Analyses of variance of the angles of maximum SLR and change in the pelvic position showed a significant F ratio (p = .01) among the active and passive trials. Post hoc analyses demonstrated significant differences (p = .01) between SLR with dorsiflexion and SLR with plantar flexion. The EMG activity among trials was not significantly different. The possible causes of the effects of dorsiflexion on SLR are discussed. We encourage clinicians to document and compare SLR with dorsiflexion and SLR with plantar flexion, and we recommend additional research to examine the relative influence of tissue structures on SLR.

title: Dorsiflexion, plantar-flexion, and neutral ankle positions during passive resistance assessments of the posterior hip and thigh muscles.
abstract: Passive straight-legged-raise (SLR) assessments have been performed with the ankle fixed in dorsiflexion (DF), plantar-flexion (PF), or neutral (NTRL) position. However, it is unclear whether ankle position contributes to differences in the passive resistance measured during an SLR assessment.



To examine the influence of ankle position during an SLR on the passive torque, range of motion (ROM), and hamstrings electromyographic (EMG) responses to passive stretch of the posterior hip and thigh muscles.



Crossover study.



Research laboratory.



A total of 13 healthy volunteers (5 men: age = 24 ± 3 years, height = 178 ± 6 cm, mass = 85 ± 10 kg; 8 women: age = 21 ± 1 years, height = 163 ± 8 cm, mass = 60 ± 6 kg).



Participants performed 6 randomly ordered passive SLR assessments involving 2 assessments at each condition, which included the ankle positioned in DF, PF, and NTRL. All SLRs were performed using an isokinetic dynamometer programmed in passive mode to move the limb toward the head at 5°/s.



During each SLR, maximal ROM was determined as the point of discomfort but not pain, as indicated by the participant. Passive torque and EMG amplitude were determined at 4 common joint angles (θ) separated by 5° during the final common 15° of ROM for each participant.



Passive torque was greater for the DF condition than the NTRL (P = .008) and PF (P = .03) conditions at θ3 and greater for the DF than NTRL condition (P = .02) at θ4. Maximal ROM was lower for the DF condition than the NTRL (P = .003) and PF (P < .001) conditions. However, we found no differences among conditions for EMG amplitude (P = .86).



These findings suggest that performing SLRs with the ankle positioned in DF may elicit greater passive torque and lower ROM than SLRs with the ankle positioned in PF or NTRL. The greater passive torque and lower ROM induced by the DF condition possibly were due to increased tension in the neural structures of the proximal thigh.

title: Contribution of pelvic and lower limb motion to increases in the angle of passive straight leg raising.
abstract: We undertook this study to determine the relative contributions of pelvic and lower limb motion to increases in the angle of passive straight leg raising in the sagittal plane. Seventeen healthy subjects underwent passive straight leg raising of their relaxed left lower limb while their right lower limb was held firmly against the table. Each subject's pelvis and left lower limb were marked so that cinematography could document motion of the pelvis and left lower limb during passive straight leg raising. Film analysis revealed that pelvic rotation began within 9 degrees of the beginning of passive straight leg raising and that the relative contribution of pelvic rotation to the angle of passive straight leg raising in relation to the horizontal plane increased in conjunction with the angle of straight leg raising. Clinicians using the passive straight-leg-raising test should be aware of the contribution of pelvic rotation to the angle of straight leg raising when interpreting test results.

title: Effects of Lumbopelvic Neutralization on the Electromyographic Activity, Lumbopelvic and Knee Motion during Seated Knee Extension in Subjects with Hamstring Shortness
abstract: The purpose of this study was to examine the effects of lumbopelvic neutralization on the angle of knee extension, lumbopelvic motion, and the electromyographic (EMG) activities of the quadriceps, hamstrings, and rectus abdominis muscles of subjects with hamstring shortness during seated knee extension.  Twenty young subjects (14 men, 6 women) with hamstring shortness were recruited for this study.  A pressure biofeedback unit was used to monitor the lumbopelvic neutralization during seated knee extension with lumbopelvic neutralization. The EMG activity and kinematic data were measured during seated knee extension with and without lumbopelvic neutralization. Surface EMG was used for measuring the muscle activities of the quadriceps, hamstrings, and rectus abdominis muscles. The angles of knee extension, lumbar flexion, lumbar rotation, and posterior pelvic tilt were measured using a 3-dimensional motion analysis system.  The angles of the lumbar flexion, lumbar rotation, posterior pelvic tilt, and knee extension decreased significantly when performing seated knee extension with lumbopelvic neutralization compared to performing the same maneuver without lumbopelvic neutralization. The EMG activities of the medial and lateral hamstrings, quadriceps, and rectus abdominis decreased significantly during seated knee extension with lumbopelvic neutralization using a pressure biofeedback unit.  Seated knee extension exercise with lumbopelvic neutralization may be useful for minimizing compensatory lumbopelvic motion and preventing compensatory hamstrings and rectus abdominis muscle activities of subjects with hamstring shortness during seated knee extension.

title: The Standing Forward Flexion Test: An Inaccurate Determinant of Sacroiliac Joint Dysfunction
abstract: Objective evidence which supports an association between the forward flexion test (FFT) and sacroiliac joint dysfunction is lacking. The purpose of this study was to investigate the occurrence of a positive FFT in a sample of young adults (N = 128), and to examine the association of factors such as low back pain, pelvic skeletal asymmetry, age, height, weight, and stance asymmetry. The history of back pain and the results of the FFT were recorded and measurements of height, weight, preferred stance angle and asymmetry ratio were taken. Descriptive statistics were used to present the anthropometric and FFT data, and t-tests were used to examine differences between females and males, and subjects with and without a positive FFT. The 0.05 level of significance was selected. Of the subjects tested 24% (n = 31) had a positive FFT and the highest occurrence of a positive FFT was in male subjects (n = 19). Nine asymptomatic subjects had a positive FFT. Statistically significant differences were observed between the positive and negative FFT groups for height, weight and asymmetry ratio (p > 0.05). It is concluded that factors other than sacroiliac joint dysfunction are likely to be the cause of a positive FFT.

title: Correlation between hamstring muscle length and pelvic tilt range during forward bending in healthy individuals: An initial evaluation
abstract: The purpose of this study was to determine if an association exists between hamstring muscle length and the angle of pelvic tilt during forward bending in a student sporting population. A bubble goniometer was used to determine angle of pelvic tilt, and the active knee extension (AKE) test used to assess hamstring muscle length in 21 asymptomatic subjects. The forward bending task was matched to the tibial length of each subject. Mean AKE was 146.5° (±9.0°) and mean angle of pelvic tilt 15.5° (±6.9°). No association was found between hamstring muscle length and total angle of pelvic tilt ( r = 0.045 ) in people with extensibility of the hamstrings within normal limits.

title: Use of noninvasive techniques for quantification of spinal range-of-motion in normal subjects and chronic low-back dysfunction patients.
abstract: Quantitative measures of physical function (range of motion, strength, stability) are critical to musculoskeletal care of the extremities, yet such objective measures in the spine are currently unavailable. In this paper, the authors present a simple, single inclinometer modification of the method of Loebl, which offers the opportunity to separate the components of the compound motion of hip and spine. Analysis of the motion in normal and chronic low-back pain patients allows differentiation of the groups, demonstration of progress in rehabilitation programs, determination of impairment, and provides tests of patient compliance and level of motivation.

title: Flexion relaxation of the hamstring muscles during lumbar-pelvic rhythm.
abstract: This study investigated the simultaneous activity of back muscles and hamstring muscles during sagittal forward body flexion and extension in healthy persons. The study was cross-sectional.



A descriptive study of paraspinal and hamstring muscle activity in normal persons during lumbar-pelvic rhythm.



A university hospital.



Forty healthy volunteers (21 men, 19 women, ages 17 to 48 years), all without back pain or other pain syndromes.



Surface electromyography (EMG) was used to follow activities in the back and the hamstring muscles. With movement sensors, real lumbar flexion was separated from simultaneous pelvic motion by monitoring the components of motion with a two-inclinometer method continuously from the initial upright posture into full flexion. All signals were sampled during real-time monitoring for off-line analyses.



Back muscle activity ceased (ie, flexion relaxation [FR] occurred) at lumbar flexion with a mean of 79 degrees. Hamstring activity lasted longer and EMG activity ceased in the hamstrings when nearly full lumbar flexion (97%) was reached. After this point total flexion and pelvic flexion continued further, so that the last part of lumbar flexion and the last part of pelvic flexion happened without back muscle activity or hamstring bracing, respectively.



FR of the back muscles during body flexion has been well established and its clinical significance in low back pain has been confirmed. In this study, it was shown for the first time that the hip extensors (ie, hamstring muscles) relax during forward flexion but with different timing. FR in hamstrings is not dependent on or coupled firmly with back muscle behavior in spinal disorders and the lumbar pelvic rhythm can be locally and only partially disturbed.

title: Adequacy of Belt-Stabilized Testing of Knee Extension Strength
abstract: Bohannon, RW, Bubela, DJ, Wang, Y-C, Magasi, SR, and Gershon, RC. Adequacy of belt-stabilized testing of knee extension strength.  2011—Tester strength can limit the forces that can be measured using a hand-held dynamometer (HHD). A solution is to use belt stabilization in conjunction with an HHD. The purposes of this study were to determine if a portable belt-stabilized HHD (BSHHD) setup was capable of measuring a broad range of isometric knee extension torques and whether isometric knee extension torques measured using a portable BSHHD system were comparable to those obtained using a Biodex isokinetic dynamometer. Participants in the study were 113 women and 71 men (14-85 years of age) community-dwelling enrollees in the National Institutes of Health Toolbox for the Assessment of Neurological and Behavioral Function. Knee extension torques measured using a BSHHD ranged from 35.0-416.0 N·m. Torques measured with the BSHHD were significantly lower (p < 0.001) than those measured using the isokinetic dynamometer (mean difference: 35.6 N·m left, 33.7 N·m right). However, the measures were highly correlated (r > 0.86, p < 0.001). Torques obtained with a BSHHD may not equal the maximum that individuals can generate, but they reflect such torques. We conclude, therefore, that a portable BSHHD setup is a viable option for measuring a wide spectrum of knee extension torques in diverse settings.

title: The Relationship Between Lower Extremity Injury, Low Back Pain, and Hip Muscle Strength in Male and Female Collegiate Athletes
abstract: ObjectiveTo determine the relationship of previous lower extremity (LE) injury and/or low back pain (LBP) on hip abduction and extension strength. DesignCohort study of college athletes at time of preparticipation screening physical. SettingAn NCAA Division I college. ParticipantsTwo hundred ten college athletes (140 males and 70 females) from an NCAA Division I school. Main Outcome MeasuresMean and maximal hip abduction and extension strengths were recorded using a specially designed dynamometer anchoring station. Previous injury to the LE or LBP in the past year was recorded via personal interview at the time of screening and verified by review of previous injury records. ResultsA significant difference in side-to-side symmetry of maximum hip extension strength was observed in female subjects who reported LE injury or LBP as compared to those who did not. Side-to-side difference in hip strength, however, did not differ between male athletes, regardless of reported LE injury or LBP status. ConclusionFemale athletes appear to have a differing response of the proximal hip musculature to LE injury or LBP, as compared with their male counterparts. Research is under way to further validate these findings. Clinical RelevanceThis study provides some reasoning to support the screening of hip strength during the preparticipation physical, as it may be important in the prevention of LE injury and LBP in collegiate athletes.

title: Validity of Isometric Muscle Strength Measurements of the Lower Limbs Using a Hand-held Dynamometer and Belt: a Comparison with an Isokinetic Dynamometer
abstract: The aim of this study was to evaluate the validity of isometric muscle strength measurements of the lower limbs and hips made with a hand-held dynamometer and belt by comparing them with measurements obtained by an isokinetic dynamometer.  The subjects were 24 healthy adults (12 men, 12 women) with a mean age of 20.4 years.  Measurements were made with both instruments on the flexors, extensors, abductors, adductors, external rotators and internal rotators of the hip and flexors and extensors of the knee.  Measurements obtained with the hand-held dynamometer and belt were significantly lower than those obtained with the isokinetic dynamometer. Pearson’s correlation coefficients for the measurements made with the two instruments ranged from 0.52 to 0.88 for all muscle groups except the hip abductors which was 0.34. In the hip abductors, the coefficient was 0.65 when forces of 450 N and higher were excluded.  Isometric muscle strength measurements of the lower limbs and hips obtained with a hand-held dynamometer and belt are considered to be valid except for measurement of hip abduction of subjects with high muscle strength.

title: Hip- and knee-strength assessments using a hand-held dynamometer with external belt-fixation are inter-tester reliable
abstract: PurposeIn football, ice-hockey, and track and field, injuries have been predicted, and hip- and knee-strength deficits quantified using hand-held dynamometry (HHD). However, systematic bias exists when testers of different sex and strength perform the measurements. Belt-fixation of the dynamometer may resolve this. The aim of the present study was therefore to examine the inter-tester reliability concerning strength assessments of isometric hip abduction, adduction, flexion, extension and knee-flexion strength, using HHD with external belt-fixation.MethodsTwenty-one healthy athletes (6 women), 30 (8.6) (mean (SD)) years of age, were included. Two physiotherapy students (1 female and 1 male) performed all the measurements after careful instruction and procedure training. Isometric hip abduction, adduction, flexion, extension, and knee-flexion strength were tested. The tester-order and hip-action order were randomised.ResultsNo systematic between-tester differences (bias) were observed for any of the hip or knee actions. The intra-class correlation coefficients (ICC 2.1) ranged from 0.76 to 0.95. Furthermore, standard errors of measurement in per cent (SEM %) ranged from 5 to 11 %, and minimal detectable change in per cent (MDC %) from 14 to 29 % for the different hip and knee actions.ConclusionThe present study shows that isometric hip- and knee-strength measurements have acceptable inter-tester reliability at the group level, when testing strong individuals, using HHD with belt-fixation. This procedure is therefore perfectly suited for the evaluation and monitoring of strong athletes with hip, groin and hamstring injuries, some of the most common and troublesome injuries in sports.Levels of evidenceDiagnostic, Level III.

title: Effect of head and limb orientation on trunk muscle activation during abdominal hollowing in chronic low back pain
abstract: BackgroundIndividuals with chronic low back pain (CLBP) have altered activations patterns of the anterior trunk musculature when performing the abdominal hollowing manœuvre (attempt to pull umbilicus inward and upward towards the spine). There is a subgroup of individuals with CLBP who have high neurocognitive and sensory motor deficits with associated primitive reflexes (PR). The objective of the study was to determine if orienting the head and extremities to positions, which mimic PR patterns would alter anterior trunk musculature activation during the hollowing manoeuvre.MethodsThis study compared surface electromyography (EMG) of bilateral rectus abdominis (RA), external oblique (EO), and internal obliques (IO) of 11 individuals with CLBP and evident PR to 9 healthy controls during the hollowing manoeuvre in seven positions of the upper quarter.ResultsUsing magnitude based inferences it was likely (>75%) that controls had a higher ratio of left IO:RA activation with supine (cervical neutral), asymmetrical tonic neck reflex (ATNR) left and right, right cervical rotation and cervical extension positions. A higher ratio of right IO:RA was detected in the cervical neutral and ATNR left position for the control group. The CLBP group were more likely to show higher activation of the left RA in the cervical neutral, ATNR left and right, right cervical rotation and cervical flexion positions as well as in the cervical neutral and cervical flexion position for the right RA.ConclusionsIndividuals with CLBP and PR manifested altered activation patterns during the hollowing maneuver compared to healthy controls and that altering cervical and upper extremity position can diminish the group differences. Altered cervical and limb positions can change the activation levels of the IO and EO in both groups.

title: Symmetry of timing of hip and lumbopelvic rotation motion in 2 different subgroups of people with low back pain.
abstract: To examine whether lumbopelvic motion associated with a clinical test of active hip lateral rotation (HLR) systematically varied between people classified into 1 of 2 low back pain (LBP) subgroups: lumbar rotation (Rot) or lumbar rotation with extension (RotExt); and, specifically, to determine whether the timing of hip and lumbopelvic rotation with HLR would be more symmetric, right versus left, in people in the Rot subgroup compared with the RotExt subgroup.



Two-group, cross-sectional.



A university-based movement science laboratory.



Subjects were 39 people (23 men, 16 women; mean age, 28.1+/-8.0 y) with chronic or recurrent LBP who regularly participated in a rotation-related sport and associated their LBP symptoms with participation.



Not applicable.



Subjects participated in a standardized clinical examination to classify their LBP problem. A 3-dimensional movement system was used to capture kinematics of hip and lumbopelvic rotation during the test of active HLR. To examine timing of motion between the hip and lumbopelvic region, the difference in time between the start of hip and lumbopelvic rotation was calculated (startdiff). Symmetry of motion was indexed by the correlation (r) between right and left startdiff and the coefficient of determination (r2) for each LBP subgroup.



There were no significant differences between the 2 groups with regard to subject, LBP, activity, and range of motion variables (P range, >.05 for all comparisons). People in the Rot subgroup displayed significantly more symmetry of timing of hip and lumbopelvic rotation motion with active HLR than people in the RotExt subgroup (Rot subgroup: r=.94, r2=.88, P=.00; RotExt subgroup: r=.31, r2=.10, P=.12).



People in the Rot and RotExt subgroups displayed systematic differences in how they moved the hip and lumbopelvic region with the clinical test of active HLR. These findings are potentially important because such differences in movement patterns between subgroups of people with LBP suggest different contributing factors and may require different treatments to affect the movement patterns.

title: Patterns of Lumbar Region Movement During Trunk Lateral Bending in 2 Subgroups of People With Low Back Pain
abstract: The movement system impairment (MSI) system is one proposed system for classifying low back pain (LBP) problems. Prior clinical data and observations for the MSI system suggest that different LBP subgroups demonstrate different patterns of movement during clinical tests, such as trunk lateral bending (TLB). The purpose of this study, therefore, was to examine the validity of the observation that lumbar region (LR) movement patterns during TLB are different between 2 subgroups of people with LBP: lumbar rotation with extension (Rotation With Extension) and lumbar rotation (Rotation). 
 Subjects
 Participants were 44 people (28 men and 16 women; age [X̄±SD], 28.5±8.4 years) with chronic or recurrent LBP. 
 Methods
 Each participant's LBP problem was classified with the MSI system. Kinematic variables were measured, and LBP symptoms were recorded during the TLB test. 
 Results
 People in the 2 LBP subgroups demonstrated different patterns of LR movement during TLB. People in the Rotation With Extension subgroup displayed an asymmetric (right versus left) pattern of LR movement across the TLB movement, whereas people in the Rotation subgroup displayed a symmetric pattern of LR movement. Equal proportions of people in the 2 subgroups reported an increase in symptoms with the TLB test. 
 Discussion and Conclusion
 The patterns of LR movement across the TLB movement were different in 2 subgroups of people with LBP. The difference in the LR movement patterns between subgroups may be an important factor to consider in specifying the details of the interventions for these 2 LBP problems.

title: Non-specific chronic low back pain: differences in spinal kinematics in subgroups during functional tasks
abstract: PurposeA multidimensional classification approach suggests that motor control impairment subgroups exist in non-specific chronic low back pain (NSCLBP). Differences in sitting lumbar posture have been identified between two such subgroups [flexion pattern (FP) and active extension pattern (AEP)] and healthy individuals; however, functional spinal movement has not been explored. This study will evaluate whether NSCLBP subgroups exhibit regional spinal kinematic differences, compared to healthy individuals, during functional tasks.MethodsObservational, cross-sectional study design. Spinal kinematics of 50 NSCLBP subjects (27 FP, 23 AEP) and 28 healthy individuals were investigated using 3D motion analysis (Vicon™) during functional tasks [reaching upwards, step down, step up, lifting, and replacing a box, stand-to-sit, sit-to-stand, bending to retrieve (and returning from retrieving) a pen from the floor]. Mean sagittal angle for the total thoracic, total lumbar, upper thoracic, lower thoracic, upper lumbar, and lower lumbar regions between groups was compared.ResultsSignificant differences were observed in lower thoracic and upper lumbar regions between NSCLBP subgroups during most tasks. Significant differences were observed between the FP and healthy group in the lower thoracic region during stand-to-sit-to-stand tasks and bending (and returning from) to retrieve a pen from the floor. All significant results demonstrated the FP group to operate in comparatively greater flexion.ConclusionsThe thoraco-lumbar spine discriminated between FP and AEP, and FP and healthy groups during functional tasks. FP individuals demonstrated more kyphotic thoraco-lumbar postures, which may be pain provocative. No significant differences were observed between AEP and healthy groups, suggesting that alternative mechanisms may occur in AEP.

title: Hamstring shortening in healthy adults.
abstract: Hamstring shortening (HS) causes changes in the posture and walking ability in spastic children, however, there are no studies defining the abnormalities in patellar alignment in individuals with HS.Twenty-five patients with a primary complaint of anterior knee pain, having HS detected at physical examination, and 11 healthy individuals without any HS or knee discomfort as a control group are included in this study. Serial x-rays of the spine, pelvis and knee are taken and knee x-rays are evaluated for the position of the patella in both groups.In patients with Knee Extension Deficit (KED) ≥ 60°, the Blackburne-Peel ratio is lower and the Insall-Salvati ratio is higher than the other groups, denoting a cephalic location of the patella (p < 0.05). There are no changes in the congruency and sulcus angles between the HS and control groups. Vertebral and pelvic changes correlate well with the literature, confirming that significant alterations occur after 60° of KED in adults.The extensor mechanism of the knee is affected and patella is located higher than normal in patients with severe HS, which may be a cause for knee discomfort. In the light of these findings, a routine knee extension deficit examination can be suggested in the initial evaluation of knee discomfort.

title: A QUANTITATIVE STUDY OF MUSCLE FACTORS IN THE CHRONIC LOW BACK SYNDROME
abstract: Low back pain is an extremely prevalent and frustrating cause of disability. With the usual exception of childhood and adolescence, it is common to all age groups. A voluminous literature exists in which every conceivable approach to treatment has been attempted and every possible contributing factor studied. When an organic basis for the low back pain is clearly apparent, its management may be relatively simple. However, in a significant number of patients no obvious organic cause is demonstrable. Many reasons for the chronicity of symptoms without obvious etiology have been advanced. The role of emotional factors has been stressed repeatedly, as has the importance of the soft tissues in precipitating and maintaining the low back symptoms (1-3). Dysfunction of the sacroiliac and interarticular joints of the vertebrae has been proposed as an important factor (4), and there is considerable interest in the role of muscle strength and balance ( 1--3, 5). Biomechanical studies (1) have demonstrated the importance of the trunk musculature in providing extrinsic stability to the spine. Probably all of these factors contribute to the development and persistence of the low back syndrome. Their relative importance in any individual case varies greatly and the frequency with which they occur has yet to be clearly established. From our clinical experience, it appeared that a muscle component might well be a common contributing factor, and one that was amenable to treatment. To investigate the nature, mechanism and importance of muscular elements, a series of controlled studies was begun. The present report is concerned with studies on trunk strength and hamstring-muscle tightness as factors in the chronic low back syndrome.

title: Risk factors for the development of low back pain in adolescence.
abstract: A previous history and earlier onset of low back pain are associated with chronic low back pain in adults, implying that prevention in adolescence may have a positive impact in adulthood. The study objectives were to determine the incidence of low back pain in a cohort of adolescents and to ascertain risk factors. A cohort of 502 high school students in Montreal, Canada, was evaluated during 1995-1996 at three separate times, 6 months apart. The outcome was low back pain occurrence at a frequency of at least once a week in the previous 6 months. Of the 377 adolescents who did not complain of low back pain at the initial evaluation, 65 developed low back pain over the year (cumulative incidence, 17 percent). Risk factors associated with development of low back pain were high growth (odds ratio = 3.09; 95 percent confidence interval (CI): 1.53, 6.01), smoking (odds ratio = 2.20; 95% CI: 1.38, 3.50), tight quadriceps femoris (odds ratio = 1.02; 95% CI: 1.00, 1.05), tight hamstrings (odds ratio = 1.04; 95% CI: 1.01, 1.06), and working during the school year (odds ratio = 1.33; 95% CI: 1.03, 1.71). Modifying such risk factors as smoking and poor leg flexibility may potentially serve to prevent the development of low back pain in adolescents.

title: Restriction in lateral bending range of motion, lumbar lordosis, and hamstring flexibility predicts the development of low back pain: a systematic review of prospective cohort studies
abstract: BackgroundLow back pain (LBP) is an increasingly common condition worldwide with significant costs associated with its management. Identification of musculoskeletal risk factors that can be treated clinically before the development of LBP could reduce costs and improve the quality of life of individuals. Therefore the aim was to systematically review prospective cohort studies investigating lower back and / or lower limb musculoskeletal risk factors in the development of LBP.MethodsMEDLINE, EMBASE, AMED, CINAHL, SPORTDiscus, and the Cochrane Library were searched from inception to February 2016. No age, gender or occupational restrictions of participants were applied. Articles had to be published in English and have a 12 month follow-up period. Musculoskeletal risk factors were defined as any osseous, ligamentous, or muscular structure that was quantifiably measured at baseline. Studies were excluded if participants were pregnant, diagnosed with cancer, or had previous low back surgery. Two authors independently reviewed and selected relevant articles. Methodological quality was evaluated independently by two reviewers using a generic tool for observational studies.ResultsTwelve articles which evaluated musculoskeletal risk factors for the development of low back pain in 5459 participants were included. Individual meta-analyses were conducted based on risk factors common between studies. Meta-analysis revealed that reduced lateral flexion range of motion (OR = 0.41, 95% CI 0.24-0.73, p = 0.002), limited lumbar lordosis (OR = 0.73, 95% CI 0.55-0.98, p = 0.034), and restricted hamstring range of motion (OR = 0.96, 95% CI 0.94-0.98, p = 0.001) were significantly associated with the development of low back pain. Meta-analyses on lumbar extension range of motion, quadriceps flexibility, fingertip to floor distance, lumbar flexion range of motion, back muscle strength, back muscle endurance, abdominal strength, erector spinae cross sectional area, and quadratus lumborum cross sectional area showed non-significant results.ConclusionIn summary, we found that a restriction in lateral flexion and hamstring range of motion as well as limited lumbar lordosis were associated with an increased risk of developing LBP. Future research should aim to measure additional lower limb musculoskeletal risk factors, have follow up periods of 6-12 months, adopt a standardised definition of LBP, and only include participants who have no history of LBP.

title: Evaluation of intra-subject difference in hamstring flexibility in patients with low back pain: An exploratory study.
abstract: To evaluate the extent of intra-subject difference in hamstring flexibility and its possible relationship to the severity of Low Back Pain (LBP). A secondary purpose was to evaluate the extent of intra-rater reliability using both electrogoniometer and conventional goniometer for measuring hamstring tightness.



Potential correlations between muscle impairments and LBP may lead to more effective treatments and prevention strategies.



Seventy two participants with mechanical LBP were recruited for this study. The sample included; 41 females, 31 males with a mean age of 33.69 ± (11.04) years, height of 170 ± (9) cm, and weight of 79.5 ± (1.6) kg. Hamstring length was detected indirectly using the Active Knee Extension method in the 90/90 position from supine. The amount of extension was measured using both electro-goniometer (EG)and a standard goniometer (SG).



Right lower extremities of these patients were significantly more flexible than left ones at α = 0.025 (t_{72}= 3.14, p=0.002). Similarly, dominant lower extremities of these patients were significantly more flexible than the non dominant ones at α=0.025 (t _{72}=2.56, p=0.013). Additionally, Oswestry scores of the patients were significantly and positively correlated with the amount of hamstring tightness of the right lower extremities (r=0.244, p=0.039), left lower extremities (r=0.225, p=0.048) and the average of both sides (r=0.24, p=0.039). However, the Oswestry scores were negatively, but insignificantly correlated to the absolute difference between right and left extremities at (r=-0.156, p=0.091). Finally, the extent of intrasubject reliability in measuring hamstring tightness using EG and SG was found to be high (ICC=0.93).CONCLUSION: There is a possible relation between mild mechanical LBP and hamstrings tightness. It was found that the more the tightness, the higher the severity of LBP that patient experienced. Also, these patients had one of their lower extremities significantly tighter than the other. Such tightness was successfully detected utilizing both EG and SG. These findings and their possible pathomechanical consequences should be considered while constructing effective rehabilitation protocols for patients with mechanical LBP.

title: Extensibility and stiffness of the hamstrings in patients with nonspecific low back pain.
abstract: To investigate the extensibility and stiffness of the hamstrings in patients with nonspecific low back pain (LBP).



An experimental design.



A university laboratory for human movement analysis in a department of rehabilitation medicine.



Forty subjects, a patient group (20) and a healthy control group (20).



Subjects laid supine on an examination table with a lift frame, with left leg placed in a sling at the ankle. Straight leg raising, pulling force, and activity of hamstring and back muscles were recorded with electrodes. Patients indicated when they experienced tension or pain.



The lift force, leg excursion, pelvic-femoral angle, first sensation of pain, and the electromyogram of the hamstrings and back muscles measured in an experimental straight-leg raising set-up.



The patient group showed a significant restriction in range of motion (ROM) and extensibility of the hamstrings compared with the control group. No significant difference in hamstring muscle stiffness can be assessed between both groups.



The restricted ROM and the decreased extensibility of the hamstrings in patients with nonspecific LBP is not caused by increased muscle stiffness of the hamstrings, but determined by the stretch tolerance of the patients.

title: Pain, depression, and illness behavior in a Pain Clinic population
abstract: &NA; The relationship between depression, illness behavior and persistent pain was studied in 100 patients referred to the University of Washington Hospital Pain Clinic. The instruments used were the Illness Behavior Questionnaire (IBQ) and the Levine‐Pilowsky Depression Questionnaire (LPD). To delineate those aspects of illness behavior characteristic of the Pain Clinic group, their scores were compared to those attained on the IBQ by a Family Medicine Clinic sample. The Pain Clinic group showed greater conviction of disease and somatic preoccupation than the comparison group. Further, they were reluctant to consider their health problems in psychologic terms, and denied current life problems. The Pain Clinic group's performance on the LPD indicated a low degree of depressive affect overall and few patients manifesting a depressive syndrome. The association between IBQ and depression scores suggests that the predominant clinical pattern presented by pain clinic patients is best characterized as a form of “abnormal illness behavior”.

title: Differentiation of depression from chronic pain with the dexamethasone suppression test and DSM-III.
abstract: The concept of chronic pain has become enmeshed with depression. In an attempt to unravel this complex relationship, the authors studied a uniform group of 42 patients with chronic pain, i.e., patients who had chronic low back pain with defined organic pathology, in relation to the dexamethasone suppression test (DST). The results were analyzed in relation to the presence or absence of major depression and cortisol suppression. Forty-one percent of the patients with major depression had abnormal cortisol responses to dexamethasone administration; all patients without major depression had normal responses. These results suggest that chronic pain patients differ from patients with major depression and a positive DST.

title: Psychiatric Illness and Chronic Low-Back Pain: The Mind and the Spine—Which Goes First?
abstract: Two hundred chronic low-back pain patients entering a functional restoration program were assessed for current and lifetime psychiatric syndromes using a structured psychiatric interview to make DSM-III-R diagnoses. Results showed that, even when the somewhat controversial category of somatoform pain disorder was excluded, 77% of patients met lifetime diagnostic criteria and 59% demonstrated current symptoms for at least one psychiatric diagnosis. The most common of these were major depression, substance abuse, and anxiety disorders. In addition, 51% met criteria for at least one personality disorder. All of the prevalence rates were significantly greater than the base rate for the general population. Finally, and most importantly, of these patients with a positive lifetime history for psychiatric syndromes, 54% of those with depression, 94% of those with substance abuse, and 95% of those with anxiety disorders had experienced these syndromes before the onset of their back pain. These are the first results to indicate that certain psychiatric syndromes appear to precede chronic iow-back pain (substance abuse and anxiety disorders), whereas others (specifically, major depression) develop either before or after the onset of chronic low-back pain. Such findings substantially add to our understanding of causality and predisposition in the relationship between psychiatric disorders and chronic low-back pain. They also clearly reveal that clinicians should be aware of potentially high rates of emotional distress syndromes in chronic low-back pain and enlist mental health professionals to help maximize treatment outcomes.

title: Toward more accurate use of the Beck Depression Inventory with chronic back pain patients.
abstract: To improve the accuracy of the Beck Depression Inventory (BDI) in assessing depression in chronic back pain (CBP) patients, the pattern of depression symptomatology was evaluated.



Analyses of BDI data obtained from nondepressed and depressed CBP patients were conducted to identify the major factors that differentiated among the patient groups.



CBP patients were recruited from a tertiary rehabilitation center.



One hundred one nondepressed and 99 depressed CBP patients from the tertiary treatment center.



Analyses of the BDI data revealed a general factor of depression severity that excluded items reflecting weight loss, sleep disturbance, and work inhibition. In addition, these analyses yielded a second factor reflecting somatic concerns and disability. Weight loss, sleep disturbance, and work inhibition failed to differentiate the depressed from the nondepressed CBP subjects, suggesting that these symptoms have poor diagnostic potential for CBP patients.



This study demonstrated that the BDI can be used to generate important information about the severity of interference posed by pain on the functioning of an individual, while allowing for an independent evaluation of subjective indices of depression and somatic disturbances that need to be attended to by clinicians.

title: Cognitive Functional Therapy for Disabling Nonspecific Chronic Low Back Pain: Multiple Case-Cohort Study
abstract: Multiple dimensions across the biopsychosocial spectrum are relevant in the management of nonspecific chronic low back pain (NSCLBP). Cognitive functional therapy is a behaviorally targeted intervention that combines normalization of movement and abolition of pain behaviors with cognitive reconceptualization of the NSCLBP problem while targeting psychosocial and lifestyle barriers to recovery.  The purpose of this study was to examine the effectiveness of cognitive functional therapy for people with disabling NSCLBP who were awaiting an appointment with a specialist medical consultant.  A multiple case-cohort study (n=26) consisting of 3 phases (A1–B–A2) was conducted.  Measurement phase A1 was a baseline phase during which measurements of pain and functional disability were collected on 3 occasions over 3 months for all participants. During phase B, participants entered a cognitive functional therapy intervention program involving approximately 8 treatments over an average of 12 weeks. Finally, phase A2 was a 12-month, no-treatment follow-up period. Outcomes were analyzed using repeated-measures analysis of variance or Friedman test (with post hoc Bonferroni correction) across 7 time intervals, depending on normality of data distribution.  Statistically significant reductions in both functional disability and pain were observed immediately postintervention and were maintained over the 12-month follow-up period. These reductions reached clinical significance for both disability and pain. Secondary psychosocial outcomes, including depression, anxiety, back beliefs, fear of physical activity, catastrophizing, and self-efficacy, were significantly improved after the intervention.  The study was not a randomized controlled trial. Although primary outcome data were self-reported, the assessor was not blinded.  These promising results suggest that cognitive functional therapy should be compared with other conservative interventions for the management of disabling NSCLBP in secondary care settings in large randomized clinical trials.

title: Epidemiologic evidence for the relation between socioeconomic status and depression, obesity, and diabetes.
abstract: Many of the leading causes of death and disability in the United States and other countries are associated with socioeconomic position. The least well-off suffer a disproportionate share of the burden of disease, including depression, obesity, and diabetes. Research suggests that the adverse effects of economic hardship on both mental and physical health and functioning are evident at young ages and persist across the lifecourse. Moreover, these associations are seen across cultures. Data from four large epidemiologic studies on the role of psychological characteristics, social factors, and behaviors in health and disease risk are presented that highlight the striking associations between socioeconomic factors and chronic diseases. Data from these studies demonstrate that the effects of economic disadvantage are cumulative, with the greatest risk of poor mental and physical health seen among those who experienced sustained hardship over time.

title: Comparison of psoas major muscle thickness measured by sonography during active straight leg raising in subjects with and without uncontrolled lumbopelvic rotation.
abstract: The psoas major (PM) is important for stabilizing lumbopelvic region during active straight leg raising (ASLR). Uncontrolled lumbopelvic rotation (ULPR) frequently occurs during ASLR in subjects with poor lumbo-pelvic stability and may contribute to asymmetric symptoms including pain in lumbopelvic region.



This study compared the thickness of contralateral PM (cPM) using ultrasound imaging during ASLR in subjects with and without ULPR.



Healthy male subjects (18 without ULPR, 19 with ULPR) were recruited. The thickness of the cPM during rest and ASLR without loading and with a 1-kg load was measured by ultrasound imaging. The relative muscle thickness was calculated as the thickness during ASLR/thickness at rest. Two-way mixed-model analysis of variance was used to identify significant differences in the relative thickness of the cPM between groups and within a loading status. The level of statistical significance was set at α = 0.05.



The resting thickness of the cPM in subjects without ULPR did not differ from that of subjects with ULPR. The relative thickness of the cPM in subjects without ULPR was significantly greater during ASLR than that in subjects with ULPR both without loading and with a load (p < 0.01). No significant change in thickness of the cPM was evident in those with ULPR.



The thickness of the cPM was significantly greater during ASLR in subjects without ULPR than with ULPR. This result indicates that persons with ULPR have less activation of the cPM to stabilize the lumbar spine during ASLR.

title: The psoas major muscle: a three-dimensional geometric study.
abstract: The purpose of this study was to use anatomical data obtained from cadavers, and geometrical scaling data obtained from MRI scans of living subjects, to assess the line of action and mechanical function of the psoas major muscle in three dimensions about each lumbar spine level. In addition, the line of action of the psoas major was documented as a function of lordosis. A total of seven cadavers were dissected from which fibre/tendon architecture was measured, while MRI scans were performed on 15 males to obtain centroid paths and area scales of the muscle over its length. In this way, the curving path of muscle line of action was accommodated together with force and moment predictions that recognized the presence of a tendon at lower lumbar levels (up to L3 in some subjects) significantly increasing the stress. Results confirm that the mechanics of the psoas cannot be adequately represented with a series of straight line vectors from vertebral origins to insertion. Moreover, the mechanical action of the psoas major does not change as a function of lumbar spine lordosis as the muscle path of action changes in accordance with changes in spine posture. Functionally, contrary to claims, the psoas cannot act as a 'derotator' of the spine, does not impose large shear forces on the spine in any posture except at L5-S1, and cannot have major affects to 'control lordosis'. It has the potential to stabilize the lumbar spine with compressive loading and with bilateral activation, to laterally flex it, and can create large anterior shear forces but only at L5-S1.

title: The function of the psoas major muscle: passive kinetics and morphological studies using donated cadavers
abstract: This study was carried out to analyze the phasic heterogeneity in the function of the psoas major muscle (PMM) depending on the flexion angle at the hip joint. The study design was a passive kinetic experiment using 25 osteoligamentous specimens with the PMM tendon. We measured the flexion angle of the hip joint where the PMM tendon loses contact with the femoral head and pelvic surface. Ten osteoligamentous specimens were used for additional measurements of the tensile force and pressure exerted on the PMM and/or at the bone-tendon interface when the PMM tendon was gently pulled in line with the PMM origin in the supine position. The tension loading the PMM tendon was measured at seven different angled positions of hip joint flexion (0°, 15°, 30°, 45°, 60°, 75°, and 90°), using a load cell attached to a traction appliance. The pressure was measured at each of eight sites along the long axis of the PMM, using a pressure sensor. The PMM tendon lost contact with the femoral head at angled positions of 14° (average) hip flexion, and lost contact with the iliopectineal eminence at positions of 54° (average). The tension was stronger at angled positions of 0°–30° at the hip joint. The pressure on the femoral head and pelvic surface were stronger at positions of 0°–30° at the hip joint. The pressure on the femoral head was strongest at a hip flexion of 0°. The tensile force markedly decreased at 45°–60° flexion at the hip joint, while the pressure on the femoral head gradually reduced to zero in the same phases. We concluded that the PMM works phasically: (1) as an erector of the lumbar vertebral column, as well as a stabilizer of the femoral head in the acetabulum at 0°–15° flexion at the hip joint; (2) less as a stabilizer, in contrast to maintaining its erector action, at 15°–45°; and (3) as an effective flexor of the lower extremity, at 45°–60°.

title: CT measurement of trunk muscle areas in patients with chronic low back pain.
abstract: The objective of this study was to determine the cross-sectional area changes of the paraspinal, isolated multifidus, quadratus lumborum, psoas, and the gluteus maximus muscles with CT in patients with chronic low back pain.



In this study, we evaluated 36 patients with chronic low back pain and 34 healthy volunteers. The mean age of the patients was 43.2 +/- 6.9 years (range, 30- 58 years) and the mean age of control group was 44.4 +/- 6.9 years (range, 31-61 years). We defined pain that lasts more then one year as chronic pain. Female patients were selected for standardization. All patients were housewives. None of the patients or controls engaged in physical activity other than routine housework. We used a visual analog scale and the Oswestry Pain Questionnaire for clinical evaluation. We made CT cross-sections of the paraspinal muscles at the upper and lower endplates of L4, and of the gluteus maximus at the head of the interfoveal level.



In the patient group the multifidus, psoas, and quadratus lumborum cross-sectional areas were smaller than in the control group, and the P values were P = 0.002, P = 0.042, and P = 0.047, respectively, at the L4 endplate. At the L4 endplate level, cross-sectional areas of the multifidus and paravertebral muscles in the patient group were smaller than in the control group, and the difference was statistically significant (P = 0.001, P = 0.010, respectively). We did not find any significant difference between the patient and the control groups in gluteus maximus cross-sectional area.



Chronic low back pain caused atrophy of the paraspinal, isolated multifidus, quadratus lumborum, psoas, and the gluteus maximus muscles to varying degrees, which was most prominent in the multifidus. Atrophy was noted in all of the studied muscles, except the gluteus maximus. The reliability of CT in measuring the cross-sectional areas of the back muscles was acceptable.

title: Changes in the Cross-Sectional Area of Multifidus and Psoas in Patients With Unilateral Back Pain: The Relationship to Pain and Disability
abstract: Prospective, cross-sectional observational study.  The aim of this study was to determine if there was an association between wasting of psoas and multifidus as observed on MRI scans and the presenting symptoms, reported pathology, pain, or disability of a cohort of patients presenting with unilateral low back pain.  Current physiotherapy practice is often based on localized spine stabilizing muscle exercises; most attention has been focused on transversus abdominus and multifidus with relatively little on psoas.  Fifty consecutive patients presenting to a back pain triage clinic with unilateral low back pain lasting more than 12 weeks were recruited. The cross-sectional surface area (CSA) of the muscles was measured. Duration of symptoms, rating of pain, self-reported function, and the presence of neural compression were recorded.  Data analysis compared the CSA between the symptomatic and asymptomatic sides. There was a statistically significant difference in CSA between the sides (P < 0.001). There was a positive correlation between the percentage decrease in CSA of psoas on the affected side and with the rating of pain (rho = 0.608, P < 0.01), reported nerve root compression (rho = 0.812, P < 0.01), and the duration of symptoms (rho = 0.886, P < 0.01). There was an association between decrease in the CSA of multifidus and duration of symptoms.  Atrophy of multifidus has been used as one of the rationales for spine stabilization exercises. The evidence of coexisting atrophy of psoas and multifidus suggests that a future area for study should be selective exercise training of psoas, which is less commonly used in clinical practice.

title: Associations Between Physical Activity and Reduced Rates of Hopelessness, Depression, and Suicidal Behavior Among College Students
abstract: The authors explored associations among types of physical activity and hopelessness, depression, and suicidal behavior among college students.  Participants included 43,499 college students aged 18 to 25 who completed the 2005 National College Health Assessment conducted by the American College Health Association.  The authors used logistic regression modeling to compare the odds of experiencing hopelessness, depression, and suicidal behavior in students who engaged in various levels of aerobic and strength or toning activity with students who did not perform these activities.  Men and women who engaged in some physical activity each week demonstrated a reduced risk of hopelessness, depression, and suicidal behavior compared with their inactive counterparts.  This study provides empirical evidence that establishes the association between physical activity, especially aerobic activity, and reduced risk of hopelessness, depression, and suicidal behavior among college students.

title: Sex Differences in the Presentation of Chronic Low Back Pain
abstract: Sex differences in 351 patients with chronic low back pain were examined. Biological, psychological, and psychosocial factors were considered. Sex differences in adaptive functioning were consistent with traditional gender roles. Significant interactions were found for sex and employment status, and sex and marital status. Retired women reported more pain and less activity than retired men. Retired men reported the least pain of any group. Outdoor work and social activities show opposite within-group patterns for men and women when stratifiedby employment status. Marriage was associated with more household work for women and less for men. The financial and social contexts of employment status and marriage are different for men and women. Results suggest the treatment of women with chronic low back pain requires attention to work in the home and the financial and social context of work outside the home.

title: Hamstring muscle tightness. Reliability of an active-knee-extension test.
abstract: The purpose of this study was to examine intratester reliability of a test designed to measure tightness in the hamstring muscles. The test measures the angle of knee flexion with a pendulum goniometer after active knee extension with the hip stabilized at 90 degrees flexion. The angle of knee flexion represents hamstring tightness. After an instruction session for the subjects, the hamstring muscle tightness of both extremities of 15 men was measured during test and retest sessions. The reliability coefficients for test and retest measurements were .99 for the left extremity and .99 for the right extremity. High reliability resulted from strict body stabilization methods, a well-defined end point of motion, and accurate instrument placement. If conducted properly, the test should provide therapists with an objective and reliable tool for measuring hamstring muscle tightness.

title: Movements induced by straight leg raising in the lumbo-sacral roots, nerves and plexus, and in the intrapelvic section of the sciatic nerve
abstract: It is well known that on straight leg raising (Lasegue's test) traction is exerted on the sciatic nerve, the lumbo-sacral nerve roots, and the dura. The roots move through their intervertebral foramina for distances which may amount to several millimetres. If, however, dissection is made from the front instead of from the back (which is the usual approach) the course of the nerves and their changes with leg movements can be followed to the sciatic notch. This more extensive examination reveals several points not generally appreciated in descriptions of the sciatic nerve or in consideration ofthe significance of the straight-leg-raising test. In particular, it shows that nerve movements become progressively greater with increasing distance from the intervertebral foramina, and it establishes the existence of multiple points of pressure against the bone. Alterations in tension and the degree to which the roots are adherent to the intervertebral foramina are open to inspection. All of these changes can readily be examined and correlated with age. This paper incorporates the objective findings and the conclusions reached after a considerable number of dissections made by an anterior approach after routine necropsy, and it records measurements of the movements of those nerves commonly implicated in sciatic pain in a smaller series of 30 cases.

title: Reduced Spinal Cord Movement With the Straight Leg Raise Test in Patients With Lumbar Intervertebral Disc Herniation
abstract: Controlled radiological study.  To explore whether impairment of neural excursion during the straight leg raise test occurs in patients with sciatic symptoms secondary to lumbar intervertebral disc herniation (LIDH).  Earlier studies have shown that during the straight leg raise (SLR) test in asymptomatic volunteers tensile forces are consistently transmitted throughout the neural system and the thoracolumbar spinal cord slides distally.  Fifteen patients with sciatic symptoms due to subacute LIDH were studied with a 1.5 T magnetic resonance scanner. First, a spine specialist diagnosed the LIDH using conventional scanning sequences. Following this subjects were scanned using different scanning sequences for planning and measurement purposes. Displacement of the conus medullaris during the unilateral and bilateral SLR was quantified reliably with a randomized procedure and compared between manoeuvres.  The results showed 66.6% less excursion of conus medullaris with SLR performed on the symptomatic side compared with excursions measured with SLR performed on the asymptomatic side (p ⩽ 0.001).  In patients with LIDH, the neural displacement on the symptomatic side is significantly reduced by the compressing IVD herniation. To our knowledge, these are the first data in intact human subjects to support the limitation of neural movements in the vertebral canal with LIDH.