bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the assessment of lower-limb muscular power capability
Authors: Liebermann Dario G. , Katz Larry 
Published: October 2018

Purpose: This study assessed the reliability and validity of different methods used to estimate lower-limb muscular power capability based on mechanical variables. For this purpose, vertical jumping was compared with isokinetic knee extensions and with power tests used by practitioners. Methods: Four groups of subjects (N=106) were tested in different conditions. Group-I performed countermovement vertical jumps (CMJ) on a force plate followed by left and right knee extensions on an isokinetic device at 120, 180 and 240 deg · s $^{-1}$ . Group-II performed CMJ trials followed by 20-m sprints, hand-reach jumps and 1RM leg-press testing. Group-III carried out squat jumps (SJ) in addition to CMJ trials. Finally, Group-IV performed the CMJ test and was retested twice after a short inter-session interval (1–4 days) and after a long one (4.5–5 months). The Pearson correlation was used to assess the validity and reliability of CMJ (p ≤ 0.01, **). Results: Mean peak power during CMJ was correlated with sprint time(r=-0.882 $^{**}$ ) and leg-press 1 RM(r=0.797 $^{**}$ ), but less with peak hand-reach height(r=0.695; p ≤ 0.05). Isokinetic knee extension power showed also a significant correlation with CMJ power, but its strength depended on the angular velocity (Isok-120 r=0.702 $^{**}$ ; Isok-180 r=0.737 $^{**}$ ; Isok-240 r=0.599 $^{**}$ ). Test-retests showed a strong correlation after a short interval(r=0.915 $^{**}$ ) and after a long one(r=0.890 $^{**}$ ). Using the SJ technique did not have any effect on reliability (r=0.914 $^{**}$ ). Conclusions: CMJ matches other methods used for testing lower-limb power capability. It is highly reliable and it allows a valid assessment of muscular power. Since CMJ is also simple and accurate to perform, it is the recommended method.
An update of neck muscle strength: From isometric to isokinetic assessment
Authors: Portero Pierre , Genriès Valérie 
Published: October 2018

Pain syndromes in the neck-shoulder region resulting in neck sprain after repetitive mechanical loads imposed on the neck and shoulders during car or sporting accidents do not appear to be an isolated phenomenon. These pathologies require a specific muscle assessment for the diagnosis and the management of patients. Isometric muscle assessment is classically used, involving a maximal voluntary contraction performed at specified joint position against unyielding resistance. In spite of high reliability and reproducibility, this method does not allow the investigation of the dynamic properties of muscle. For this reason, an isokinetic method has become an increasingly popular modality in rehabilitative and sport medicine. Its concept has the advantage of providing a method of measuring strength during dynamic movements in a highly standardised situation. Although trunk muscles have been widely explored by the isokinetic technique, the cervical spine has not received the benefit of isokinetic technological progress. Recently, a specific neck device has been designed and validated, permitting the first isokinetic approach of neck muscles in different healthy and sporting populations. This article examines the use of isometric neck muscle assessment and proposes the isokinetic method as a tool for assessing the cervical spine in exercise sciences, medicine, and rehabilitation.
Isokinetic dynamometry of weak muscles
Authors: Tiffreau Vincent , Turlure Alain , Viet Ghislaine , Thevenon André 
Published: October 2018

The aims of the study were to assess the reproducibility and validity of very weak knee flexors and extensors muscle strength with a new isokinetic evaluation procedure. Subjects and methods: Reproducibility mean and maximal work without correction of gravity was first assessed in 14 neuromuscular patients, at 10°/s. Three patients suffering from Guillain-Barre Syndrome were then investigated at different states of recovery. Maximal concentric effort was performed at 10°/s and 30°/s. Acute correction of gravity was performed as forces values measured during passive mobilisation were removed from active measurements. Correlation between manual muscle testing and maximal moment and mean work was explored. Results: Reproducibility was judged acceptable. Intraclass correlation coefficients ranged from 0.7 to 0.84. In the correlation study, manual muscle assessment ranged from 2 to 4 and peak of forces ranged from 0.4 Nm to 51.88 Nm. There was a significant positive relationship as Spearman Correlation coefficients ranged from 0.77 to 0.89. Conclusion: Weak muscle isokinetic evaluation is reproducible and well correlated to clinical evaluation. This evaluation procedure could be of great interest in neurological diseases investigations.
Reproducibility of concentric and eccentric isokinetic strength of the shoulder rotators in normal subjects 40 to 55 years old
Authors: Dauty Marc , Delbrouck Claire , Huguet Dominique , Rousseau Bertrand , Potiron-Josse Michèle , Dubois Charles 
Published: October 2018

The purpose of this study was to define the test-retest reproducibility of concentric and eccentric isokinetic measurements of shoulder rotators. It was carried out at a 26 day ± 4 interval. Fourteen healthy volunteer subjects (7 men and 7 women), aged between 40 and 55 years (47.5 ± 5.6 years), were included. Evaluation was carried out with a Cybex Norm dynamometer and the reliability was calculated according to the intra-class correlation coefficient (ICC 2.1). The protocol was randomised for the shoulder and for sets of concentric (con) and eccentric (ecc) tests. Concentric sets consisted of 5 movements of internal (IR) and external rotation(ER) at the speed of 60°/sec. then 120°/sec. Eccentric performance was recorded only for the external rotators, to determine the ratio ER $_{ecc}$ / IR $_{con}$ . Results indicated excellent reproducibility for the peak torque (0.91–0.98), total work (0.88–0.96) and average power(0.83–0.94) in concentric muscle action for internal and external rotators and in eccentric muscle action for external rotators at 60 and 120°/sec. On the other hand the strength ratio: ER $_{con}$ / IR $_{con}$ and ER $_{ecc}$ / IR $_{con}$ should be interpreted with caution because of a lower reproducibility (ICC: 0.53–0.83). In conclusion, isokinetic findings relating to concentric and eccentric performance of the internal and external rotators of the shoulder are reproducible under the present protocol. These findings may serve for assessing rotator cuff function at the age where the incidence of rotator cuff overuse becomes a serious problem.
Age-related changes in concentric and eccentric muscle strength in the lower and upper extremity: A cross-sectional study
Authors: Delbaere K. , Bourgois J. , Witvrouw E.E. , Willems T.M. , Cambier D.C. 
Published: October 2018

Objective: To determine the influence of ageing on lean muscle area and isometric and concentric and eccentric muscle strength in the upper and lower extremity in a cross-sectional study design. Subjects and methods: Lean muscle area and maximal muscle strength(isometric and isokinetic, 60° and 120°/s) of both upper and lower extremity were assessed of 45 men and 56 women (20 to 89 years). Results: One-way variance analysis and regression analyses revealed a parallel decline with age in both sexes for maximal muscle strength. The decline in maximal muscle strength from age 60 was 34 to 45% in men and 11 to 32% in women in the arms and 40 to 47% in men and 37 to 45% in women in the legs. Isometric, concentric and eccentric contractions showed a similar decline in ageing in both sexes. There was a better maintenance with age of the strength in the arms than in the legs (p < 0.01) and at 120°/s than at 60°/s(p < 0.05). Conclusions: The present findings suggest a parallel decline in lean muscle area and strength and similar losses in isometric, concentric and eccentric strength with increasing age.
Manual massage effect in knee extensors peak torque during short-term intense continuous concentric–eccentric isokinetic exercise in female elite athletes
Authors: Sykaras E. , Mylonas A. , Malliaropoulos N. , Zakas A. , Papacostas Em. 
Published: October 2018

Manual massage is considered an important part of athletic rehabilitation or preparation for training and competition. Objective: To study the possible effects of manual massage on concentric and eccentric peak torque of knee extensors, when applied during intervals of exercise. Methods: Twelve elite female Tae Kwon Do athletes were tested twice during a week (different extremity each) in continuous concentric/eccentric isokinetic exercise (6 sets of 10 repetitions, with 2 minutes intervals). Manual massage was applied during breaks to the extremity (massage extremity) while for the other limb (control extremity) the interval was passive. For both groups peak torque was measured 3 minutes after the last set. The same test was performed 3 minutes prior to the first set. The best performance was recorded pre- and post-exercise and the results were compared. Results: For both groups peak torque (concentric and eccentric) was reduced after the exercise protocol. In the massage group the reduction was lower and significantly different for eccentric type of muscle work (p < 0.05). Conclusions: Application of manual massage during isokinetic exercise intervals has an enhancing effect on the peak eccentric torque of the knee extensors.
Plantar flexor muscle action while sitting, standing and prone in patients with upper motor neuron lesion due to stroke
Authors: Carlsson U. , Henning G.-B. , Svantesson U. , Sunnerhagen K.S. 
Published: October 2018

Aim: The purpose of the present study was to investigate the effect of different test positions on the static strength of ankle joint muscles and the EMG activity of the calf and thigh muscles in patients with upper motor neuron lesion due to stroke. Set-up: Static torque was recorded during isometric plantar flexion muscle action while sitting, standing and lying prone, in both the affected and the non-affected leg in seven patients. The EMG activity was recorded in the soleus, medial gastrocnemius, anterior tibial and rectus femoris muscles. Results: The affected leg showed lowered torque values in all positions compared to the non-affected leg. There were no significant differences in the torque values depending on positions nor in the EMG recordings. When the standing position was used as "normative", there was a significant difference in the EMG values between the affected and non-affected leg when sitting with the knee bent and while standing with the knee straight; i.e. in closed-chain exercises. Discussion: Training and testing of strength in the plantar flexor muscles in stroke patients may be done in both open and closed-chain exercises as far as force development is concerned. However, the outcome of these different types of exercises might be influenced by the position of the knee joint since the gastrocnemius is a two-joint muscle.
Intramachine and intermachine reproducibility of concentric performance: A study of the Con-Trex MJ and the Cybex Norm dynamometers
Authors: Bardis C. , Kalamara E. , Loucaides G. , Michaelides M. , Tsaklis P. 
Published: October 2018

Introduction: There is minimal information in the literature concerning the intramachine reliability of the new Isokinetic dynamometer Con-Trex MJ, and the intermachine reproducibility of this instrument with the Cybex Norm isokinetic dynamometer. Objective: The purpose of this study was to provide some insight with regard to the reproducibility of Con-Trex MJ in measuring the knee muscle performance in flexion and extension (concentric) and to compare the variability of measurement between Con-Trex and Cybex Norm. Methods: 35 (70 legs) male subjects with no previous history of any knee pathology volunteered for the study. Intramachine reproducibility was evaluated by assessing 30 legs twice on the Con-Trex MJ, within 2 to 7 days, at angular velocities of 60°, 180° and 300°/sec. Intermachine reproducibility was evaluated by assessing 40 legs randomly on the Con-Trex MJ and Cybex Norm within 2 to 7 days at 60° and 180°/sec. Coefficient of variation (CV) was used to determine the reproducibility of repeated measurements at $p< 0.01$. Results: Intra: The variability of measurements of Con-Trex for Peak Torque, was 5.19–5.68% for extension and 4.84–7.33% for flexion depending on the angular velocity. This is acceptable for clinical and research studies. Inter: Between the two Isokinetic devices there was a greater CV for Peak Torque ranging 7.28–9.17% for extension and 8.54–15.84% for flexion. Conclusion: Based on the results of the present study, comparisons of results between the two devices may not be valid. The results for knee flexion and extension measurements at 60° and 180°/sec recorded with Con-Trex were consistently greater than the values recorded with the Cybex Norm.
Muscular force-velocity parameters during single joint and multiple joint sagittal activities of the upper limb
Authors: Stefańska Małgorzata 
Published: October 2018

Objective: To determine the force-velocity characteristics (F-v) of upper limb muscles and specify the muscle group which has a predominant influence on the global F-v characteristics of the limb. Subjects and methods: 30 healthy young men participated in this study which consisted of two experiments. In the first the moment developed by flexors and extensors of shoulder, elbow and radio-carpal joints at angular velocities ranging 0–300°/s was measured isokinetically. In the second experiment global F-v characteristics were assessed statically and dynamically. Results: Elbow extensors had a predominant impact on the shape of the global F-v characteristics of the examined limb. Conclusions: The force-velocity characteristics provide comprehensive information regarding the capacity of the examined muscle groups. This information is of value in setting target scores for total upper limb strength in the context of specific habitual activities such as chair rise.
Concentric isokinetic dynamometry of the shoulder: Which parameters discriminate between healthy subjects and patients with shoulder disorders?
Authors: van Meeteren Jetty , Roebroeck Marij E. , Selles Ruud W. , Stijnen Theo , Stam Henk J. 
Published: October 2018

There is no consensus on the optimal isokinetic dynamometry parameters to clinically assess shoulder disorders. Therefore, this study aimed to establish which parameters are best able to discriminate between shoulder patients and healthy subjects, focusing on peak torques and peak torque ratios. Isokinetic dynamometric measurements of both shoulders were made in 20 healthy subjects and these data were compared with baseline measurements in 9 patients with shoulder disorders. The different outcome measures were compared by testing for significant group differences between patients and healthy subjects and by scoring how the patient data compared to the normal range of values found in healthy subjects. Significant differences between patients and healthy subjects were found for the peak torques, but not for the agonist-antagonist peak torque ratios. In addition, there were significant differences for the dominant/non dominant ratios of the peak torques but not for the dominant/non dominant ratios of the peak torque ratios. The percentage of patients with a standard deviation score outside the 90% normal distribution of healthy subjects was largest (>78%) for the involved/uninvolved (I/U) ratio of the peak torques. It was concluded that bilateral comparison of peak torques is the most appropriate outcome parameter to distinguish patients from healthy subjects.
Trunk strength patterns in elite rowers
Authors: McGregor Alison , Hill Adam , Grewar Jane 
Published: October 2018

This study compared the strength and fatigue characteristics of the trunk in international rowers and non-rowing controls. 39 international rowers(mean age 27.4 ± 4.9, 20 females, 19 males) and 35 control subjects who did not row (mean age 23.2 ± 3.2, 20 males, 15 females) were recruited and parameters of trunk flexion-extension strength including isometric fatigue were recorded tested on a Cybex Norm Isokinetic Testing System. The rowers were significantly stronger (P < 0.001) in all measured parameters of back strength than the control group (isometric extension strength 249.3 N/m ± 52.1 (SD) in rowers compared with 178.6 N/m ± 85 (SD) in controls). Greater strength in the rowing group was most significant in the later stages of range. Both populations demonstrated marked fatigue of the trunk muscles, although this was more prominent in the rowers (p < 0.05 in flexion). In general, values of extensor strength were markedly greater than flexion strength, although this was less so in rowers. Consequently the trunk extensor-flexor ratios were lower in the rowing population. In conclusion, elite rowers are significantly stronger than control subjects. It is of interest that these strength gains are not proportional throughout range and this may be related to the rowing action, and may be of importance with respect to future development of LBP.
The size of physiological spinal curvatures and functional parameters of trunk muscles in children with idiopathic scoliosis
Authors: Anwajler Joanna , Skrzek Anna , Mraz Małgorzata , Skolimowski Tadeusz , Woźniewski Marek 
Published: October 2018

Objective: To examine the influence of the spinal contour changes on the functioning of trunk muscles in children with idiopathic scoliosis. Background: In the early stage of scoliosis progression, changes in the sagittal plane often manifest themselves in curving in the lumbar lordosis and curving out of the thoracal scoliosis. An increase or decrease in the size of anteroposterior spinal curvatures may disturb functioning of the trunk muscles. Method: Thirty five girls (mean age: 14.7 ± 2.3 yr) with idiopathic scoliosis took part in this study. In terms of location, thoracal scoliosis was dominant. Photogrammetry with automatic Moiré fringe analysis system was used to assess the spinal contour. Activity of the spinal flexors and extensors was tested isokinetically at 3 angular velocities: 60, 90 and 120°/s. The measured force-velocity parameters were analysed according to location of the scoliosis (primary thoracal or primary thoraco-lumbar scoliosis), the size of the deformity and posture type: lordotic, kyphotic or equivalent (balanced) (a posture type, where thoracic kyphosis and lumbar lordosis are of similar size – they are balanced). Results and conclusions: A step-by-step discriminant analysis indicated that parameters associated with muscle endurance were the most diversified regardless of the division criterion applied. It was also revealed that functioning of the trunk muscles was related to the spine asymmetry in the frontal plane as well as on the spinal contour in the sagittal plane.
Strength of trunk and thigh musculature and bone mineral density in women aged 40–79 years
Authors: Skrzek Anna , Bolanowski Marek 
Published: October 2018

Background: Decreased bone strength together with impaired physical efficiency followed by falls are the most important causes of osteoporotic fractures in elderly population. Objectives: To examine the influence of age on isokinetic trunk and knee flexion and extension torque properties, and to study their associations with bone mineral density in women. Material and methods: 288 women were divided into 4 age groups(40–49, 50–59, 60–69, 70–79 years). Isokinetic concentric studies of spinal and knee extensors and flexors were carried out at 90°/s and 120°/s, for spine, and 60°/s and 180°/s for knees. Bone mineral density was measured in the proximal femur by DXA. Results: The different strength parameters (peak torque, peak torque/body mass, average torque of five repetitions) decreased and the time to reach peak torque increased with age. Some relations have been noted between these isokinetic parameters and bone mineral density. Conclusions: Age-related deterioration in strength-velocity parameters of knee and spinal muscles are co-incidental with a gradual decrease in proximal femur BMD in older women.
Peripheral isokinetic muscle function and cardiorespiratory capacity in coronary artery disease patients
Authors: Elleuch M.H. , Ghroubi S. , Chaari M. , Elleuch H. , Massmoudi K. , Abdenadher M. , Trabelssi I. , Akrout M. , Feki H. , Frikha I. , Dammak J. , Kammoun S. , Zouari N. 
Published: October 2018

Objective: The aim of this study was to determine if the diminished aerobic capacity of coronary artery disease (CAD) in male patients is accompanied by a peripheral impaired skeletal muscle function and to assess the correlation between the isokinetic strength and aerobic aptitude of these patients. Materials and methods: Fifteen CAD patients and 15 healthy subjects(age: 60 ± 6 vs 57 ± 3.5 years old) performed both maximal exercise testing, an isokinetic assessment of knee muscles and a 6-minute walking test. The quadriceps and hamstrings were tested at 150 and 180°/s while being monitored with ECG. The cardio-respiratory and mechanical parameters (VO2, VT, HR, and power) were measured at ventilatory threshold and at maximal effort during a maximal exercise testing. Results: Isokinetic assessment was conducted successfully with all patients. No rhythm irregularity or hemodynamic anomalies were observed in the 2 groups. Muscle testing revealed significant strength impairment. Quadriceps peak torque, at 150°/s was 77 ± 16 Nm in patients vs. 99 ± 23 Nm in controls, (p<0.01) while at 180°/s the values were 71 ± 14 vs. 91 ± 23 Nm, (p<0.01), respectively. For the hamstrings the values were respectively 49 ± 16 vs. 66 ± 14 Nm, (p <0.01) and 47± 10 vs. 60 ± 12 Nm, (p<0.01). CAD subjects presented a deficient aerobic capacity compared to the healthy control group at maximal effort (Vo2 maximal uptake: Vo2 max: 20.34± 4.95 vs. 29.16 ± 7.68 ml mn $^{-1}$ kg $^{-1}$ , (p=0.01); maximal ventilation Ve max: 58.18 ± 16.28 vs 84 ± 24.45 ml mn ${-1}$ , (p<0.05); heart rate: HR max: 118 ± 21 vs 152 ± 13 beats mn $^{-1}$ , (p<0.001); maximal power: P max: 102 ± 31 vs. 153 ± 33 W. (p<0.001) and at ventilatory threshold: VT (Vo2: 13.77 ± 2.33 vs. 17.08 ± 3.59 ml mn $^{-1}$ kg $^{-1}$ , (p< 0.05); VE: 29.64± 6.64 vs. 37.76 ± 7.2 ml mn $^{-1}$ ,(p<0.05); HR: 86 ± 14 vs. 111 ± 15 beats mn $^{-1}$ , (p=0.001); but no significant difference was noticed for power (P: 61 ± 12 vs. 76 ± 24 W:). We also noticed that isokinetic muscle strength and O2 peak were not related to each other and are therefore independent. Conclusion: This study shows that CAD patients, compared to healthy subjects, have impaired cardio respiratory capacities which are accompanied by increased muscle fatigability. Isokinetic muscle strength and maximal aerobic capacity are independent of each other. An isokinetic muscle assessment in these patients must be conducted systematically and seems to have a considerable value in cardiovascular rehabilitation.