bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of inversion traction on pain sensation, lumbar flexibility and trunk muscles strength in patients with chronic low back pain
Authors: Kim Jae-Deung , Oh Hye-Won , Lee Jung-Hyun , Cha Jun-Youl , Ko Il-Gyu , Jee Yong-Seok
Published: October 2018

BACKGROUND: Effectiveness of inversion traction has been revealed in patients with chronic low back pain (CLBP), however, it is still unknown as to which angles of inversion traction positively affect patients with CLBP.

OBJECTIVE: To investigate the angle-effects of inversion traction on pain sensation, lumbar flexibility, and trunk muscles (flexors and extensors) strength in patients with CLBP after an 8 week treatment program.

METHODS: Forty-seven women suffering nonspecific CLBP for 23.00± 5.45 weeks were included prospectively and randomized into 3 groups: supine group (SG; n=15), inversion −30° group (I30G; n=18), and inversion −60° group (I60G; n=14), respectively. Each group completed a 3-minute × 3-set inversion traction protocol at 0°, inverted−30°, or inverted −60°, respectively for 4 days a week during 8 weeks. The outcome measures included rating of pain using the visual analogue scale (VAS), flexibility of lumbosacral joint, and the isokinetic strength of the trunk flexors and extensors at 60°/s.

RESULTS: Pain was significantly improved after 8 weeks. The reductions observed in VAS scores were lower in the I60G compared with the changes in I30G and SG. Significant interaction effects were observed in trunk flexion and extension particularly in the I60G condition. There was also a significant increase in the extensor peak torque of the I60G.

CONCLUSIONS: Inversion traction at angle of −60° reduced back pain or discomfort and improved lumbar flexibility and isokinetic trunk extensor strength in patients with CLBP following an 8 week program. Therefore, this treatment modality may be suitable for patient groups of similar CLBP phenomenology.
Ultrasonography of the deep abdominal muscles at rest and during the drawing-in maneuver: A comparative study of Japanese adolescent vs. adult soccer players
Authors: Watanabe Hiroyuki , Abe Hiroshi , Tojima Michio , Yoshimoto Masumi , Takahira Naonobu , Torii Suguru
Published: October 2018

OBJECTIVE: The purpose of this study was to clarify the characteristics of abdominal deep muscles in adolescent soccer players.

METHODS: Participants were 53 soccer players from junior high school and 14 adult soccer players. The deep abdominal muscles of both sides were imaged by ultrasonography. Abdominal muscles on the dominant leg side were selected as the targets of measurements, and measurements of the transversus abdominis (TrA) and internal oblique (IO) muscle were conducted. The muscle thickness of these muscles was measured at rest and during contraction (while drawing-in of the abdominal wall) and served as the basis for comparing the adolescent and adult players.

RESULTS: While no significant inter-group differences were noted in the thickness of the TrA or IO muscle at rest, a significant difference was observed during the drawing-in maneuver.

CONCLUSION: The deep abdominal muscles of adolescent soccer players have not likely reached full maturity.
Inflammatory responses after different velocities of eccentric exercise
Authors: Conceição Miguel Soares , Libardi Cleiton A. , Chacon-Mikahil Mara Patrícia T. , Nogueira Felipe Romano Damas , Vechin Felipe Cassaro , Bonganha Valéria , Bernardes Celene Fernandes , Madruga Vera Aparecida , Cavaglieri Claudia Regina
Published: October 2018

OBJECTIVE: The present study aimed to verify the indirect markers of muscle damage and inflammatory response following different velocities of eccentric exercise in women.

METHODS: Nine women performed isokinetic eccentric actions at a slow velocity (Ecc30 group, 23.8 ± 2.0 years; 57.8 ± 7.0 Kg; 1.6± 0.5 m) and another ten women performed at high velocity (Ecc210 group, 22.2 ± 3.9 years; 56.4 ± 6.0 Kg; 1.6 ± 0.5 m). Maximal voluntary isometric contraction (MVIC), range of motion (ROM), upper-arm circumference, muscle soreness, creatine kinase (CK), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) were measured before, immediately after (except CK and cytokines), and 24, 48 and 72 h following exercise. Normalized changes in the variables following exercise were compared between velocities by a mixed model.

RESULTS: The Ecc30 demonstrated greater CK activity than the Ecc210(group vs. time interaction, P< 0.001). A group effect for circumference and ROM (P< 0.001) and a time effect for circumference (P=0.003), ROM (P=0.004), soreness (P< 0.001), TNF-α (P=0.004), IL-6 (P=0.001) and IL-10(P=0.041) were found. The Ecc30 showed large effect sizes for TNF-α and IL-6 compared to Ecc210, which presented small and moderate effect sizes, respectively. IL-10 showed a moderate effect size for both groups.

CONCLUSIONS: The velocity of the eccentric exercise does not modulate the systemic anti-inflammatory response, at least for a low number of muscle contractions performed by a small muscle group in women.
Portable belt-stabilized hand-held dynamometry set-up for measuring knee extension force
Authors: Bohannon Richard W. , Pritchard Robert O. , Glenney Susan S.
Published: October 2018

The purpose of this paper is to describe a portable belt-stabilized hand-held dynamometry (HHD) set-up for measuring knee extension force and to compare the magnitude and reliability of forces obtained with the set-up to those obtained without belt-stabilization. Measures for single-limb knee extension force were obtained via HHD from 16 young participants by 2 testers of substantially different strength. Measurements were obtained during 2 sessions 1 week apart. Testing was performed with participants in a bariatric chair – with and without HHD belt-stabilization. Data from the first session were used to compare the magnitude of knee extension forces. Data from both sessions were used to examine reliability via intraclass correlation coefficients (ICCs) and Bland-Altman plots. Forces measured with belt-stabilization were significantly (p< 0.001) higher than those measured without belt-stabilization. The differences were greater for male participants (p=0.006) and the female tester(p=0.001). Intertester reliability was poor for measurements obtained without belt-stabilization (ICC=0.17) but good for measurements obtained with belt-stabilization (ICC=0.84). Differences between testers increased with the magnitude of force measured when no belt-stabilization was provided but not when belt-stabilization was used. Test-retest reliability was good when belt-stabilization was employed (ICC=0.87 and 0.92). When belt-stabilization was not used, the test-retest reliability was acceptable for the male tester (ICC=0.77) but not the female tester (ICC=0.50). In conclusion, the set-up examined is affordable, portable and easy to assemble. It allows for rapid testing of knee extension strength. With HHD belt-stabilization, the set-up can be recommended for clinicians and researchers requiring objective measures of knee extension strength in diverse settings.
The influence of running and cycling on subsequent maximal muscular performance
Authors: Wilhelm Eurico N. , Radaelli Regis , Perin Diana , Cunha Giovani S. , Cadore Eduardo L. , Laitano Orlando , Reischak-Oliveira Alvaro , Pinto Ronei S.
Published: October 2018

BACKGROUND AND OBJECTIVE: The extent to which moderate intensity running or cycling impact subsequent maximal neuromuscular performance is unclear. Thus, the aim of the present study was to evaluate the effect of moderate intensity and volume running and cycling on maximal and explosive muscle strength.

METHODS: Ten young physically active men were recruited and had their knee extension isometric peak torque, rate of torque development (RTD), and counter movement jump height measured at a baseline reference condition (REF) and after moderate intensity 30 min running(RUN) or cycling (CYC). Electromyographic activity of the quadriceps muscles was obtained during the isometric tests.

RESULTS: No significant differences were found between conditions for isometric peak torque (p> 0.05), RTD (p> 0.05), countermovement jump (p> 0.05), and the electromyographic amplitude (p> 0.05).

CONCLUSION: The present data indicate that maximal and explosive lower limb muscle strength is not compromised after 30 minutes of moderate intensity continuous exercise, independent of the mode of the exercise performed.
Effect of low to moderate intensity walking and cycling on glycaemic and metabolic control in type 1 diabetes mellitus adolescent males: A randomized controlled trial
Authors: Tomar Rakesh , Hamdan Mohammmed , Al-Qahtani Mohammad Hussain
Published: October 2018

BACKGROUND: Type 1 diabetes mellitus (T1DM) is characterized by an autoimmune destruction of pancreatic beta cells, i.e., the immune system destroys the special cells that make and secrete insulin.

OBJECTIVE: To evaluate the effect of 12 weeks exercise programme on glycaemic and metabolic control in T1DM adolescents.

METHODS: Twenty-four T1DM adolescent males(12–16 y) were randomised into an exercise (n=12) and control group (n=12). Twelve weeks of exercise programme was administered to the exercise group. Two patients, one in each group discontinued training. Training intensity was 40–60% of maximum heart rate for a duration 60 min, 3 times a week.

RESULTS: No significant improvement was seen in HbA $_{1c}$ (P=0.598), low density lipoprotein (P=0.264), high density lipoprotein (P=0.276) and triglycerides (P=0.490) in the exercise group but significant improvement was observed in insulin dose (P=0.000) and total cholesterol (P=0.035).

CONCLUSIONS: Twelve weeks of closely supervised exercise programme enhanced reduction in insulin dose and lowered the total cholesterol T1DM adolescent male and could be recommended as a part of the management of T1DM.
Kinesio Taping improves shoulder internal rotation and the external/internal rotator strength ratio in patients with rotator cuff tendinitis
Authors: Kim Soo-Yong , Kang Min-Hyeok , Kim Eui-Ryong , Oh Jae-Seop
Published: October 2018

BACKGROUND: Although Kinesio Taping (KT) may increase muscle strength, few studies have examined the effectiveness of KT on muscle strength in patients with rotator cuff tendinitis.

OBJECTIVE: To investigate the effect of KT on the isokinetic strength of the shoulder internal rotator (IR) and external rotator (ER) muscles in patients with rotator cuff tendinitis.

METHODS: Thirteen patients with rotator cuff tendinitis participated in this study. Shoulder IR and ER strength was measured concentrically (at 60 and 180°/s) before and after applying KT. The PT of each muscle group as well as the ER to IR ratios served as the outcome parameters.

RESULTS: The PT (both absolute and bodyweight normalized) of the IRs was significantly higher post-KT compared to pre-KT at both angular velocities. The ER/IR ratio was significantly lower post-KT than pre-KT at 60°/s.

CONCLUSIONS: These findings suggest that KT may effectively increase the shoulder IR muscle strength and help restore the shoulder ER/IR balance with decreased ratios in patients with rotator cuff tendinitis.
Moderate intensity and volume downhill run does not impair knee joint stability at early and late phases of quadriceps/hamstrings contraction
Authors: de Oliveira Assumpção Cláudio , de Lima Leonardo Coelho Rabello , de Oliveira Felipe Bruno Dias , Greco Camila Coelho , Denadai Benedito Sérgio
Published: October 2018

BACKGROUND AND OBJECTIVE: Muscle strength imbalance can be an important factor in hamstrings muscle strain. The main purpose of this study was to investigate the effects of downhill running on hamstrings/quadriceps torque (H/Q _{torque} ) and the electromechanical delay(H/Q _{EMD} ) ratios.

METHODS: Fifteen active male individuals performed two maximal voluntary isometric contractions of the knee extensors and knee flexors, from which the maximal muscle torque, EMD and H/Q _{torque} and H/Q _{EMD} ratios were extracted. Thereafter, the participants performed a 30-minute downhill run (−16%) at 70% VO _{2} max. Dependent variables were assessed immediately before, immediately following and 48 hours after the effort.

RESULTS: Maximal isometric torque decreased significantly immediately after the downhill run for both the extensors (pre: 271.8 ± 45.9 N˙m; post: 235.5 ± 55.7 N˙m) and flexors (pre: 112.2 ± 26.3 N˙m; post: 97.7 ± 27.2 N˙m). No significant difference was identified over time for the EMD of the vastus lateralis and biceps femoris muscles. The H/Q _{torque} and H/Q _{EMD} ratios were not influenced by the downhill run.

CONCLUSION: We have demonstrated that moderate intensity and volume downhill run does not impair knee joint stability at early(H/Q _{EMD} ) and late phases (H/Q _{torque} ) of quadriceps/hamstrings contraction.
Factors influencing the reproducibility of isokinetic knee flexion and extension test findings
Authors: Alt Tobias , Knicker Axel J. , Strüder Heiko K.
Published: October 2018

BACKGROUND: Although the reliability of isokinetic strength tests of knee flexors (flex) and extensors (ext) has been examined several times, statistical evidence about the influence of internal and external factors is missing.

OBJECTIVE: This study aims to examine the impact of familiarisation, muscle group, contraction mode, angular velocity and test parameters on the reproducibility of findings derived from an isokinetic dynamometer (IsoMed 2000).

METHODS: Thirty-three male subjects (mean age: 22.3 years) with no prior experience of isokinetic exercise participated in three identical test sessions (T1, T2, T3), each separated by 48–72 h. Peak moment (PM), angle of peak moment (APM) and contractional work (CW) were determined unilaterally(left and right) during maximum concentric (con) and eccentric (ecc) knee flexion (abdominal position) and extension (supine position) at 30, 90 and 150°/s, respectively. An ANOVA with repeated measures confirmed systematic bias. Reproducibility of consecutive tests (T1–T2, T2–T3) was assessed by calculating the intra-class correlation coefficient (ICC 2,1)(relative reliability) as well as the standard error of measurement (SEM)(absolute reliability). ICC values were averaged according to respective factors (Fisher's z-transformation) and tested for significant differences by Steiger's formulas.

RESULTS: PM and CW demonstrated a high absolute reliability (SEM: 4.7–10.5%). Relative reproducibility varied considerably (p⩽ 0.05) between muscles (ecc flex > ecc ext), contraction modes (con ext > ecc ext) and test parameters (PM=CW > APM), but did not depend on angular velocity (30=90=150°/s). Due to familiarisation the reliability of PM obtained from eccentric knee extensions significantly increased (T2–T3> T1–T2).

CONCLUSIONS: These results improve the development and execution of reliable isokinetic strength testing protocols for unilateral knee flexion and extension together with the interpretation of different test parameters.
Relative muscle contribution of lower extremity muscles during isokinetic single leg squat in patients following reconstruction of the anterior cruciate ligament
Authors: Shanbehzadeh Sanaz , Amiri Ali , Pirali Milad , Nassadj Gholamhossein , Yazdi Hamid Reza , Jamshidi Ali Ashraf
Published: October 2018

BACKGROUND: The single-leg squat (SLS) is a common strengthening exercise after anterior cruciate ligament reconstruction (ACLR) surgery. The multi-joint nature of squatting may allow patients to shift the demand from the target muscle group to its synergies, thus reducing the strengthening effect of the SLS exercise.

OBJECTIVE: To compare the muscular contribution in the involved and uninvolved side of the ACLR patients and both sides of the ACLR patients with the matched control group during SLS exercise.

METHOD: Seventeen athletic men with unilateral ACL reconstruction and 16 athletic healthy men participated. Integrated Electromyography was used to calculate the relative contributions of, Vastus Medialis (VM), Vastus Lateralis (VL), rectus femoris (RF), Gluteus maximus(GMax) and Soleus (SOL) muscles to SLS performance and squat peak force was measured with a Biodex System 3 isokinetic dynamometer.

RESULTS: The VM muscle contribution was significantly lower and the VL and GMax contribution was higher on the involved side of the ACLR patients compared to their uninvolved side and the control group. The SLS peak force was significantly lower on the involved side compared to the uninvolved side.

CONCLUSION: The increased VL and GMax muscle contribution might be a compensatory mechanism for the reduced VM contribution on the involved side.
Association between clinical measures of sarcopenia in a sample of community-dwelling women
Authors: Steffl Michal , Bohannon Richard W. , Houdova Veronika , Musalek Martin , Prajerova Kveta , Cesak Petr , Petr Miroslav , Kohlikova Eva , Holmerova Iva
Published: October 2018

BACKGROUND: Sarcopenia is defined as a loss of muscle mass and strength as well as a reduction in physical performance with aging. This study was undertaken to examine the association between specific measures of muscle mass, muscle strength, and physical performance in older women.

METHODS: Sixty-nine community-dwelling women with an average age of 66 years (range 60–79) participated in this study. Their muscle mass was described using bioelectric impedance analysis (BIA), their muscle strength was characterized using hand-grip dynamometry (HGD) and their physical performance was denoted using gait speed. Associations between the measures were examined using Pearson correlations and factor analysis.

RESULTS: The correlation between muscle mass and muscle strength was strong and significant (p< 0.001), whereas the correlation between both variables and gait speed was poor and not significant. The factor analysis showed that gait speed (loading=−0.235) was not part of the same component as muscle mass and grip strength.

CONCLUSIONS: Muscle mass and muscle strength were very closely linked with one another but not with gait speed. Muscle mass and strength represent a different component of sarcopenia than physical performance, at least as represented by gait speed.
Strength and torque consistency of the hip and knee flexors and extensors: A comparative study of elderly and young individuals
Authors: Borges Viviane Santos , Domingues João Marcos , Dias Rosângela Corrêa , Garcia Patrícia Azevedo , Dvir Zeevi
Published: October 2018

OBJECTIVES: To assess the strength of the flexors and extensors of the knee and hip joints in elderly and in young individuals.

METHODS: A group of elderly women (N=47) and men (N=44) aged 65 and older and a group of young women (N=15) and men (N=15) aged between 20 and 30 years were tested for the isokinetic strength of the hip and knee flexors and extensors.

RESULTS: A typical age-related decrease in the strength of all tested muscles was observed but the decline in hip muscles strength, compared to those of the knee, was significantly lower, by about 10%. Moreover, women presented a significantly better strength preservation than men. The consistency of performing the repeated isokinetic efforts was higher, in some instances significantly so, in the older (range: 4.4–11%) than in the younger (3.5–6.3%) individuals but the differences do not seem to convey any clinical significance.

CONCLUSION: These findings enable clinicians to set valid rehabilitation goals, particularly with respect to hip dysfunction in the elderly. Furthermore, healthy elderly individuals perform maximal isokinetic tests with substantially similar degree of gross motor control compared to that of young individuals.
The association of WOMAC, HSS and isokinetic strength and fatigue of knee muscles in people with osteoarthritis following total knee replacement
Authors: Tutté María Laura , Viladomat Merce Avellanet , Coppin Oliver Valero , Cervantes Didac Haro , Muñoz Jose Ignacio Torrero
Published: October 2018

BACKGROUND: Osteoarthritis (OA) is the most prevalent joint pathology and an important cause of disability among people over 65 years of age. Following total knee replacement (TKR), which may be the only curative intervention, function is mainly affected by quadriceps weakness whose extent can accurately be assessed using isokinetic dynamometry.

AIM: To evaluate the association between the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the Hospital for Special Surgery Score (HSS) scores and knee muscle isokinetic strength and fatigue findings in TKR patients 2–5 years postoperatively as well as assess the reproducibility and validity of the isokinetic test findings in this cohort.

DESIGN: Twenty-four women who underwent TKR filled in the WOMAC and HSS questionnaires. The isokinetic test was carried out at 120 and 180°/s in concentric flexion/extension. The maximal isokinetic strength was evaluated as the peak torque (PT). Isokinetic fatigue was measured using the fatigue index and calculated based on 40 repetitions at 120°/s. The same protocol was performed 7 days apart. Test-retest reproducibility was analyzed using intraclass correlation coefficient (ICC), the standard error of measurement (SEM) and Bland Altman plots. HSS and WOMAC internal consistency was tested with Cronbach's alpha; questionnaire validity and correlations were obtained using Spearman's rho.

RESULTS: The HSS Function sub-score was significantly correlated with quadriceps PT but not with fatigue isokinetic scores. Excellent reproducibility was indicated for all outcome measures, with the exception of the HSS Knee subscore and the fatigue index.

CONCLUSIONS: Isokinetic dynamometry of the quadriceps can provide objective and useful information regarding the functional status of patients following TKR due to OA of the knee.
Effect of Different Kinetic Chain States on the Isokinetic Performance of the Lumbar Muscles
Authors: Timm Kent E.
Published: October 2018

This study examined the effects of four different lower extremity kinetic chain states (KCS) on spinal flexor and extensor muscle performance during concentric isokinetic activity. The KCS involved different combinations of joint stabilization: ankle, knee, and hip/pelvis (Closed), knee and hip/pelvis (Open 1), ankle and hip/pelvis (Open 2), and hip/pelvis (Open 3). Twenty volunteer subjects (11 males, 9 females; age range 15–23 yr) were tested on a Cybex TEF isokinetic spinal dynamometer at the speed of 60 deg/sec in a sequential repeated measures design of four different test sessions, each separated by a period of 48 h. Testing involved five maximal spinal flexion/extension repetitions through a 0–60 deg motion arc as peak torque data were collected by the device's computer system. ANOVA failed to show significant differences between test motions (p = 0.668) or the factors of test motion x KCS (p = 0.955), but did show a difference between individual KCS (p < 0.001). Post hoc Scheffe tests showed significant differences between Closed and all Open KCS, between Open 3 and the other Open KCS, but failed to show a difference between the Open 1 and Open 2 KCS. It was concluded that a Closed KCS had a greater influence on lumbar muscle output than Open KCS and that the output influence decreased as KCS became progressively less constrained.
The Effect of Anterior Cruciate Ligament Surgery on the Ankle Plantar Flexors
Authors: Herlant M. , Delahaye H. , Voisin Ph. , Bibre Ph. , Adele M.F.
Published: October 2018

Plantar flexors (PF) of sixty-two patients were tested on the Cybex II Dynamometer about three weeks after anterior cruciate ligament (ACL) surgery. Compared to the non-injured extremity, the deficit is in the range of 30–40%. The authors emphasize the important role of the PF in the stability of the knee and thus the need to reinforce them in a comprehensive program of rehabilitation after ACL surgery.
Reproducibility of Sagittal Plane Knee Translation During Isokinetic Exercises
Authors: Lysholm Marketta , Goertzen Darrell , Messner Karola
Published: October 2018

The reproducibility of sagittal plane knee translation during isokinetic exercises was measured in 10 healthy subjects. At eight different test occasions including two examiners. sagittal plane knee translation of both knees was measured with the CA-4000 system (Orthopaedic System Inc., CA) during maximum muscle forces on the Biodex machine (Biodex Medical Systems Inc., Shirley, NY) at an angular velocity of 60 deg/sec. Moderate correlations were found between the majority of the test occasions. with no differences between knees or examiners, but a high variability of sagittal plane translation was found in the individual subject (coefficient of variation (CV), 6–22%). Higher correlations were found for total translation values than for left-right knee differences. No significant within-day, day-to-day, week-to-week. and between-examiner differences were observed. but a significant change in sagittal plane translation was noted between two tests immediately following each other, the second showing an increase in sagittal plane knee translation despite a similar muscle work at both tests. The amount of total muscle work varied greatly (CV 33%) in the total group, but little in the individual subject (CV 4–10%). Consequently, a moderate positive correlation was found between the total muscle work and sagittal plane knee translation in the whole group, but only weak or no correlations in the individual subject.
The Reliability of Isometric and Isokinetic Torque Measurements of the Knee Extensors in Healthy Subjects
Authors: Stam H. J. , Binkhorst R. A. , van Nieuwenhuyzen J. F.
Published: October 2018

The purpose of this study was to establish the reliability of isometric and isokinetic torque measurements of the knee extensors in healthy volunteers assessed on the Quadriceps Dynamometer. The subjects (18 men, 16 women) were tested on three occasions, at 1-week intervals, with three different angular velocities (0, 45, and 90 deg/sec). The mean absolute torque values (range 103–206 Nm) and coefficients of variation (range 15–24%) of the knee extensors were comparable with data obtained by other investigators using a Cybex II. Interindividual variability was considerable (13–20%), as had been expected. The maximum intraindividual variability was 11%. An analysis of variance showed substantial differences within the subjects on subsequent weeks and at the different testing speeds. These results suggest that a variability of about 10% is accounted for by individual changes in torque within healthy subjects. It is to be expected that intra individual variability will be greater for patients than for healthy subjects. These data can therefore be relevant for patients in determining the reliability of strength measurements in neuromuscular disorders or in strength training.
Mode of Action and Angular Velocity Fatigue Response of the Hamstrings and Quadriceps
Authors: Emery Lovell , Sitler Michael , Ryan Jeff
Published: October 2018

The purpose of this study was to investigate the effects of fatigue on the hamstrings and quadriceps during concentric and eccentric actions at 60 and 150 deg/sec. The dominant leg of 12 subjects was tested on the Biodex B-2000 isokinetic dynamometer (Biodex Medical Systems, Shirley, NY). The results showed that the eccentric mode of action, 150 deg/sec angular velocity, and quadriceps muscle group were levels at which fatigue was significantly delayed than at corresponding levels of concentric mode of contraction, 60 deg/sec angular velocity, and hamstrings muscle group. Subsequent analysis showed a significant three-way interaction. A significant simple, main effect was determined to exist for the quadriceps muscle group at the 150 deg/sec angular velocity for mode of action; concentric fatigue was significantly greater than eccentric fatigue. The findings of the present study suggest that isokinetic fatigue training protocols must be designed to meet the specific training objectives if the desired outcomes are to be met.
Comparison of Test Data from the Cybex TEF and 6000-TMC Isokinetic Spinal Dynamometers
Authors: Timm Kent E.
Published: October 2018

This study compared the test results from two spinal isokinetic dynamometers, the Cybex TEF and the Cybex 6000-TMC (Cybex, Ronkonkoma, NY) in an effort to establish the measurement reliability of the latter device and to develop formulas for the interconversion of test results. A stratified random sample of 5,760 normal subjects (2,880 females, 2,880 males; mean age 25.0±9.9 years; age range 17–49 years) was tested on both devices under an alternate repeated-measures paradigm across the concentric isokinetic speeds of 30, 60, 90, and 120 deg/sec after standardized warmup procedures. Data for peak torque expressed as a percentage of body weight was collected from five maximal repetitions of spinal flexion and extension at all test speeds and then subjected to multiple statistical analyses. Results showed a high level of measurement reliability for both the TEF (intraclass correlation [ICC] = 0.927) and the TMC (ICC = 0.910); failed to show significant differences in subject performances across devices, speeds, genders, and motions; and showed comparison formulas of TEF = TMC + 13.325, TEF = TMC + 15.225, TEF = TMC + 15.775, and TEF = TMC + 16.775 for female and male spinal flexion and extension, respectively. The results may be useful for the design of clinical programs that include spinal isokinetic testing procedures.
Relationship between isokinetic and functional trunk strength in elite junior tennis players
Authors: Roetert E. Paul , McCormick Theodore J. , Brown Scott W. , Ellenbecker Todd S.
Published: October 2018

Elite level tennis players have shown a high incidence of lower back injuries. The objective of this study was to generate a descriptive profile of trunk extension and flexion strength as well as to examine the relationship between trunk strength and several field tests of physical fitness in elite junior tennis players. Measurements were obtained on 60 nationally ranked junior tennis players between 13 and 17 years of age. Trunk flexion and extension data were obtained concentrically on a Cybex 6000 Isokinetic dynamometer with TEF modular component at speeds of 60° s−1 and 120° s−1. Peak torque/body weight and work/bodyweight ratios were statistically analyzed in comparison to the field tests. A descriptive profile of isokinetic flexion/extension ratios was generated for elite junior tennis players. Trunk flexion/extension ratios ranged from 102 to 122% for peak torque at 60° s−1 and 120° s−1. The field tests consisted of a standardized fitness testing protocol which included measurements of strength, power, speed and agility, endurance and flexibility. The correlated measurements included the total distance thrown on a forehand, backhand, overhead, and reverse overhead medicine ball toss. The analyses yielded significant correlations (range 0.47–0.82) between all isokinetic trunk flexion/extension data and the series of four medicine ball tosses, which were used in the field as a measurement of power (P < 0.01). These results demonstrate the relationship between isokinetic trunk testing and functional movement patterns. In addition, the isokinetic testing results provide an initial profile of trunk flexion and extension strength in elite junior tennis players.
Reliability of the BTE Dynatrac isotonic dynamometer
Authors: Kovaleski John E. , Ingersoll Christopher D. , Knight Kenneth L. , Mahar Colleen P.
Published: October 2018

The BTE Dynatrac is an isotonic dynamometer in where the preset resistance determines the effort and the limb must overcome the resistance to accelerate through the ROM. Previous reliability studies of isokinetic devices do not apply to this type of dynamometer. Therefore, the purpose of this study was to assess the reliability of the BTE Dynatrac Isotonic Dynamometer using average work and power to determine whether the Dynatrac can produce consistent results under different preset loads and between exercise sessions. Twenty-nine (M = 19; F = 10) recreationally active college students underwent identical testing on three occasions. On a day before testing, peak torque was measured from a 6 s maximal voluntary isometric contraction (MVIC) at 70° of knee flexion. This value determined the preset loads used for the three isotonic testing sessions. During the isotonic sessions each subject performed six repetitions of maximal knee extensions at preset loads (20%, 40%, and 60% of MVIC) through the 90° ROM. The order of testing on each of the three nonconsecutive days was determined by using a balanced Latin Square. Average work and power were recorded and analyzed. The reliability of average power measurement was excellent regardless of the preset load (20% MVIC = 0.82; 40% MVIC = 0.83; and 60% MVIC = 0.90). The reliability of average work measurement was excellent at 60% MVIC(0.86) and 40% MVIC(0.80), but only fair at 20% MVIC(0.57). We conclude that clinicians can be confident in comparing average power measurements between sessions regardless of the preset load and for average work at the moderate to higher preset loads.
The effect of using frontal shoe orthotics and plyometric training on selected functional measurements in junior high school football players
Authors: Reaper F. , Bandy W.D. , Longinotti S. , Carson A.P. , Hattlestad M. , Culpepper H. , Campbell M.
Published: October 2018

Plyometric training incorporates quick powerful movements involving an active pre-stretching (eccentric muscle contraction) prior to concentric contraction. It has been claimed that the effect of plyometric training could be enhanced using a frontal shoe orthotic due to increased overload created by this appliance. However, no study to date has examined this claim. Therefore, the purpose of the present study was to determine whether the use of the Jumpsole, a frontal shoe orthotic, will enhance the effect of plyometric training on vertical jump, 40 yard dash time, and calf circumference. Thirty five healthy eighth and ninth grade males participating on the same junior high school football team volunteered to participate in this study. A stratified sampling technique was used to ensure similarity on a weight and position basis between a control group (18 males) and experimental group (17 males). The control group completed the 6-week training program without the Jumpsole shoe orthotic. The 6-week training program consisted of 45 min to 1 h sessions performed bi-weekly utilizing acceleration activity, skipping, lateral cone hops, bounding, jump rope, and depth (box) jumps. Vertical jump, 40 yard dash time, and calf circumference were measured before and after the 6 weeks of training. A two-way multivariate analysis of variance with repeated measures on one factor and appropriate follow-up repeated measures univariate analyses revealed that the only significant difference occurred between the pre-test and post-test (irrespective of influence of whether the subjects were in the experimental group or the control group) for the dependent variable vertical jump. These results indicate that, although the plyometric training program was effective for enhancing vertical jump, the training program did not improve speed of running or size of calf muscle. Additionally, the use of the frontal shoe orthotic in an attempt to enhance the plyometric training program was not effective.
A comparison of EMG activity between the medial and lateral heads of the gastrocnemius muscle during isometric plantar flexion contractions at various knee angles
Authors: Fiebert Ira M. , Correia Edward P. , Roach Kathryn E. , Carte Mary Beth , Cespedes John , Hemstreet Katie
Published: October 2018

Traditionally, the two-headed gastrocnemius muscle has been considered as one muscle. The purpose of this study was to delineate if electromyographic (EMG) activity differences existed between the medial and lateral gastrocnemius heads, as well as torque output, in the normal right leg, during isometric plantar flexion contractions at three knee angles. Thirty volunteers, between the ages of 18–35, participated in this study. Isometric plantar flexion, with the ankle at 90° , was performed at three knee angles; 0°, 45°, and 90°. The EMG activity was measured in root-mean-square (RMS) microvolts on the Bioscope electromyographic feedback unit, and torque output was measured on the Biodex System II Dynamometer. Results showed decreasing EMG activity of both the medial and lateral gastrocnemius heads as the knee angle changed from 0° to 90°. EMG output decreased significantly as knee flexion increased from 0° to 45° to 90° (F = 14.29, P = 0.0007). However, the pattern of EMG activity decline for medial and lateral gastrocnemius heads was significantly different (F = 4.58, P = 0.0143). Plantar flexion torque decreased significantly across the three angles (F = 94.64, P = 0.0001). It appears that the length-tension principle played a major role in the declining EMG and torque, during isometric plantar flexion. The differences of the medial and lateral gastrocnemius pattern of decline implies that the two heads of the gastrocnemius muscle should be considered as separate entities. However, many factors not controlled for in this study, may have impacted the results. Therefore, health professionals should look at this study as a preliminary study in the investigation of the activation of the medial and lateral gastrocnemius muscles, leading to further investigation.
Concentric isokinetic resistance training and quadriceps femoris cross-sectional area
Authors: Housh Dona J. , Housh Terry J. , Weir Joseph P. , Weir Loree L. , Donlin Patrick E. , Chu Wei-Kom
Published: October 2018

The purposes of this study were to determine the effects of unilateral leg extension concentric isokinetic resistance (CIR) training on: (1) hypertrophy at the largest anatomical cross-section of the vastus intermedius, vastus lateralis, vastus medialis, and rectus femoris muscles in the trained and untrained limbs and (2) strength of the quadriceps femoris muscle group in the trained and untrained limbs. Sixteen untrained young adult males [mean age 24.7 ± 5.1 (SD) years] volunteered to serve as subjects. The subjects were divided into two groups: (1) training group (TG, n = 8) and (2) control group (CG, n = 8). The TG performed six sets of ten repetitions of extension of the non-dominant leg at 120°/s three times per week for 8 weeks on a Cybex II isokinetic dynamometer. The CG did not train. Pretraining and post-training leg extension peak torque at 120°/s and the largest anatomical cross-section of each muscle of the quadriceps femoris were determined utilizing a Cybex II dynamometer and magnetic resonance imaging scanner, respectively. The results indicated a significant (P < 0.05) increase (4.6%) in the CSA of the muscles of the non-dominant (trained) quadriceps femoris as well as significant (P < 0.05) increases in both non-dominant (trained) and dominant (untrained) quadriceps femoris strength (17.7 and 9.3%, respectively). There was no hypertrophy of the muscles of the dominant (untrained) limb. These data indicated that leg extension CIR training resulted in significant increases in both CSA and strength of the non-dominant (trained) quadriceps femoris as well as a significant increase in the strength, that was not accompanied by muscular hypertrophy, of the dominant (untrained) limb.
Single versus multiple joint isokinetic testing with ACL reconstructed patients
Authors: Feiring David C. , Ellenbecker Todd S.
Published: October 2018

The purpose of this study was to compare lower extremity strength using a traditional isokinetic single joint (open kinetic chain) knee extension/flexion test and a multiple joint (closed chain) isokinetic leg press test in patients following an anterior cruciate ligament (ACL) reconstruction. Twenty three subjects underwent both isokinetic single and multiple joint testing at 180, 240, and 300°/s using a calibrated Biodex dynamometer. Testing was performed following (x = 15) weeks of accelerated knee rehabilitation with a predominantly closed chain rehabilitation protocol. Peak torque (PT) and single repetition work (SRW) were analyzed and compared bilaterally in both the single and multiple joint tests. Single joint isokinetic knee extension testing measured strength of the injured limb relative to the uninjured limb at 74–77% for (PT) with multiple joint isokinetic extension testing at 91–93% for (PT). Significant (P < 0.001) differences were identified between the bilateral comparisons measured in the single and multiple joint isokinetic testing conditions for both PT and SRW. Results from this study demonstrate significant differences between single and multiple joint isokinetic testing in the lower extremity. This information is of vital importance to clinicians interpreting results of muscle function in patients following ACL reconstruction.
The application and interpretation of intraclass correlations in the assessment of reliability in isokinetic dynamometry
Authors: Walmsley Roy P. , Amell Tyler K.
Published: October 2018

The purpose of this discussion is to review the methods utilized to calculate the intraclass correlation coefficient (ICC) as well as indications on the interpretation and application of the statistic in the assessment of reliability. The index result of the ICC and several examples of clinical and research applications of the ICC are given with respect to the reliability of isokinetic testing.
The relationship between muscle and balance performance as a function of age
Authors: Wiksten Denise L. , Perrin David H. , Hartman Mark L. , Gieck Joe , Weltman Arthur
Published: October 2018

Aging is associated with decreases in strength and muscle mass. In addition, the ability to maintain balance decreases with age. Few studies have examined the relationship between isokinetic muscle performance and balance performance. It was the purpose of this study to determine if there is a relationship between muscle and balance performance, and to discover how this relationship is affected by age. Fifty-five healthy females were recruited from two different age groups, 28 females who were 18–30 years of age mean age = 22.9 years (± 3.4), height = 163.5 cm (± 6.5), weight = 64.8 kg (± 15.7) and 26 females who were > 60 years of age mean age = 68.1 years (± 4.8), height = 159.7 cm (± 10.0), weight = 68.0 kg (± 11.4). Concentric and eccentric isokinetic muscle performance for the hip, knee, and ankle was measured using the KinCom isokinetic dynamometer. Balance performance was measured using the sharpened Romberg and one-legged stance tests. Younger subjects performed significantly better than older subjects on all muscle and balance performance variables (P = 0.05 to P = 0.0001), except the sharpened Romberg test with the eyes open. The older group exhibited significant relationships between balance and muscle performance measures (r = - 0.10 to r = 0.57). In the older group, hip muscle performance was shown to correlate significantly better with balance performance than knee or ankle muscle performance. Also noted was a significantly greater relationship between muscle performance and balance performance with the eyes closed in the older group, as compared to the younger group. This is the first study known to thoroughly examine the relationship between muscle and balance performance. The presence of significant relationships warrants further examination. It is recommended that this relationship be examined in a broad spectrum of young, old, healthy and disabled populations.
The effect of increased straight leg raise on work production in subjects with tight hamstrings
Authors: Kroll Penny G. , Muhlhauser Ronald W. , Parsons N. Cole , Taylor Christopher D.
Published: October 2018

This study examined the effect of a 20% increase in straight leg raise (SLR) on concentric isokinetic measures of work in subjects with tight hamstrings. Subjects were deemed eligible if passive SLR of the dominate limb was <70° and if subjects had no documented problems with the tested limb. Thirty-two volunteer subjects were randomly assigned to experimental and control groups (n=16 each) and baseline measures were completed. Experimental group subjects then participated in supervised stretching and a home program with SLR re-assessment prior to each supervised session. Within 24 hours of an experimental subject reaching the 20% targeted increase in SLR range, that subject and a control subject were re-tested. The results showed no significant change in work production despite a 20% increase in SLR. This study suggests that a modest increase in SLR does not adversely affect the strength of tight hamstring muscles. Clinical implications are that an increase in flexibility of a tight muscle may not adversely effect a subject's ability to maximize muscular potential.
Goal setting: An efficient way to maximise isokinetic performance
Authors: Malliou Paraskevi , Beneka Anastasia , Ginnekopoulos Konstantinos , Aggelousis Nikos , Theodorakis Yannis
Published: October 2018

The aim of this study was to examine the effectiveness of goal setting on isokinetic parameters (peak torque and isokinetic work). An experimental group n=20 and a control group N=20 of healthy physical education students were studied. Both groups participated in a four week quadriceps strengthening program on an isokinetic dynamometer with the experimental group setting specific personal goals in each training session and receiving visual feedback of their performance. Results showed that the experimental group improved both isokinetic parameters (peak torque, work) significantly more than the control p<0.05 group. The findings indicate that personal goal settings when used with visual feedback might be an important determinant for improvement of isokinetic performance.
An objective measure of lateral epicondylitis
Authors: Pearson David , Gehlsen Gale M. , Wilson Julie K. , Lee Gary , Sevier Thomas
Published: October 2018

Purpose: The purpose of this study was to develope and determine the efficacy of a middle digit isokinetic eccentric strength dynamometer (MMD) in two groups of subjects. Methodes: The first group was composed of individuals without physician diagnosed lateral epicondylitis (13 males and 14 females), and the second group was composed of individuals who had physician diagnosed lateral epicondylitis (13 males and 14 females. A middle digital extension isokinetic dynamometer measured eccentric isokinetic torque, work, power, and angle at peak torque of the third finger. Results: Test-retest correlation values ranged from 0.83 to 0.45. ANOVA indicated a significant difference in work, power and angle at peak torque were indicated between the two subject groups. Conclusion: The middle digital extension isokinetic dynamometer appears to provide an acceptable means of evaluating effects of lateral epicondylitis therapy.
Muscle strength recovery following anterior cruciate ligament reconstruction: A prospective study of 151 patients with a two-year follow-up
Authors: Holm Inger , Risberg May Arna , Aune Arne Kristian , Tjomsland Ole , Steen Harald
Published: October 2018

This prospective study evaluated the muscle strength recovery during a two year follow-up, assessed the relationship between different funtional outcome measurements and compared the outcome between younger( $<$ 25 years) and older ( $\geq$ 25 years) patients. Progress in isokinetic muscle performance was measured at all follow-up intervals up to two years postoperatively. The Cincinnati functional score showed significant improvement between all follow-up intervals. Correlation analysis showed a significant relationship between the patients' subjective assessment of knee function and muscle strength and the triple jump test. The older age group had a significant slower recovery than the younger group up to one year postoperatively.