Conséquences et prédiction des lésions musculaires des ischiojambiers à partir des paramètres isocinétiques concentriques et excentriques du joueur de football professionnelConsequences and prediction of hamstring muscle injury with concentric and eccentric isokinetic parameters in elite soccer players

OBJECTIVE: To know if isokinetic parameters identify previous hamstring (H) injury and predict a new muscle injury in high-level soccer player. METHOD: Concentric (con) and eccentric (ecc) isokinetic torque was measured at the angular speed of 60 degrees /s in 28 elite soccer players (23 years +/- 3.3; 74 kg +/- 7.5; 178 cm +/- 6.5). First, 11 players, victims of 15 moderate or major hamstring injuries in the preceding 2 years, were compared with 17 players without previous hamstring injury. Comparisons were carried out from isokinetic knee flexors-extensors ratios [Hcon/Qcon and Hecc/Qcon] and bilateral knee flexors ratios [Hcon/Hcon and Hecc/Hecc]. Secondly, all the population was followed during 12 months and the isokinetic muscular profile of players who presented a recurrence or a new hamstring muscle injury was analysed. RESULTS: A concentric ratio hamstring-to-quadriceps lower than 0.6 and a hamstring asymmetry of more than 10% do not allow to identify previous hamstring injury. On the other hand, the mixed ratio eccentric hamstring-to-concentric quadriceps lower than 0.6 represents the best indicator (probability: 77.5%). The rate of recurrence is 30% (three cases of 10) and the rate of new hamstring muscle injury is 31% (five cases of 16) (P > 0.05). One of the five injured soccer players presented a concentric ratio hamstring-to-quadriceps lower than 0.6 and no player presented a mixed ratio lower than 0.6. However, four of the five injured players presented a concentric and an eccentric asymmetry. But, it is the strongest side, which presented a new hamstring muscle injury. CONCLUSION:The mixed ratio eccentric hamstring-to-concentric quadriceps lower than 0.6 identify a previous hamstring injury despite the resumption of competitive soccer. However, this ratio and the others isokinetic studied parameters do not predict a recurrence or a new hamstring muscle injury.     

Test-retest reliability of isokinetic knee extension and flexion

OBJECTIVE: To assess reliability of isokinetic peak torque and work for knee flexion and extension. DESIGN: Single-group test-retest. SETTING: University laboratory. PARTICIPANTS: Eleven men and 7 women (mean age, 21 y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Peak torque and work for concentric and eccentric knee extension and flexion were recorded at 60 degrees/s for 3 trials on 2 occasions. Intraclass correlation coefficient model 3,1 (ICC(3,1)), standard error (SE) of measurements, and smallest real differences were calculated for the maximum and for the mean peak torque and work of the 3 repetitions. RESULTS: Relative reliability was "very high" for peak torque and work (ICC range, >.90). The SE measurements ranged between 5% and 10% of the initial values for both peak torque and work. The smallest change that indicates a real improvement for a single subject (smallest real differences) ranged from 12% to 25% for peak torque and work variables and from 25% to 30% for the peak torque ratios. CONCLUSIONS: Isokinetic concentric and eccentric knee extensor and flexor strength variables are reliable when measured by the same examiner in asymptomatic subjects.     

Influence of concentric resistance training on concentric and eccentric strength

This study investigated the effects of isokinetic concentric training on isokinetic concentric and eccentric torque outputs. Sixteen female subjects (mean age in years +/- SE = 21 +/- 1) were randomly assigned to either a training or a control group. Concentric and eccentric torques of the right knee extensors were assessed at 1.05rad.s-1 using a KinCom isokinetic dynamometer system. Each test consisted of a set of four maximal concentric and four maximal eccentric contractions of the knee extensors. The peak and average torques for each contraction were calculated using the computer software supplied by the KinCom manufacturer. On a separate day, after abstaining from heavy exercise for at least 12 hours, a single cross-sectional image of the thigh at midfemur was obtained using computer tomography (CT) scanning. From this image, cross-sectional area of the quadriceps femoris group was calculated using the computer software associated with the General Electric 9800 CT Scanning System. Training group subjects trained three days weekly for six weeks on a Cybex II+ isokinetic dynamometer, completing five sets of ten maximal effort knee extensions at an angular velocity of 1.05rad.s-1. Each set of exercise was separated by two minutes of self-selected recovery. Torque outputs were monitored daily to ensure that adequate recovery was provided between sets of exercise, and to document changes in strength as the program progressed. Significant (p less than .01) increases in peak and average concentric torque (11% and 12%, respectively), peak and average eccentric torque (18% and 21%, respectively), and muscle cross-sectional area (3.2%) were observed for training group subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reliability of measurements of concentric and eccentric isokinetic loading

The purpose of this study was to assess the reliability of a method for testing peak torque and work output of the knee extensor muscle during concentric and eccentric loading at three velocities of exercise (60 degrees, 120 degrees, and 180 degrees/sec). Fourteen healthy men (23-32 years of age) performed exercises of the quadriceps femoris muscles during concentric and eccentric loading, with a five-second pause between each contraction. Three different tests were performed on different occasions. The first exercise session was a practice session, and the next two sessions were established to collect data in a test-retest format. Peak torque and work were measured for the two testing sessions. The results of this study demonstrated that with a very specific protocol, the reliability of concentric peak torque and work measurements was excellent at 60 degrees and 120 degrees/sec and good at 180 degrees/sec. In contrast, reliability of eccentric peak torque and work measurements was good at 120 degrees and 180 degrees/sec but low at 60 degrees/sec.     

Test-retest reliability of isometric and isokinetic knee extension and flexion in patients with fibromyalgia: evaluation of the smallest real difference

Adsuar JC, Olivares PR, del Pozo-Cruz B, Parraca JA, Gusi N. Test-retest reliability of isometric and isokinetic knee extension and flexion in patients with fibromyalgia: evaluation of the smallest real difference.

Objective

To investigate the reliability of isokinetic peak torque and work and isometric peak torque measurements for knee flexion and extension in fibromyalgia (FM) patients by determining the smallest real difference (SRD).

Design

Test-retest reliability study.

Setting

University laboratory.

Participants

Women with FM (N=37) aged between 34 and 74 years.

Interventions

Not applicable.

Main Outcome Measures

The participants performed isometric, concentric, and eccentric tests of the knee. Unilateral maximal peak torque and average work were measured for each direction (flexion, extension) and contraction (isometric, concentric, eccentric) type. Relative reliability, absolute reliability, and SRD were calculated. The 3 tests were repeated after an interval of 7 days.

Results

With the exception of eccentric flexion, all peak torque measures had an intraclass correlation coefficient (ICC) of > 0.90, and all work measures had an ICC of > 0.85. The SRD ranged between 21% and 37% for all peak torque measures and between 40% and 73% for all work measures.

Conclusions

Isokinetic dynamometry provides reliable measurement of peak torque and work for isometric, concentric, and eccentric knee flexion and extension in patients with FM. The present study has generated novel SRD data, which will assist physicians, therapists, and clinicians in interpreting posttreatment changes in patients with FM.     

Reliability of knee extension and flexion measurements using the Con-Trex isokinetic dynamometer

The aim of this study was to evaluate the reliability of isokinetic and isometric assessments of the knee extensor and the flexor muscle function using the Con-Trex isokinetic dynamometer. Thirty healthy subjects (15 males, 15 females) were tested and retested 7 days later for maximal strength (isokinetic peak torque, work, power and angle of peak torque as well as isometric maximal voluntary contraction torque and rate of torque development) and fatigue (per cent loss and linear slope of torque and work across a series of 20 contractions). For both the knee extensor and the flexor muscle groups, all strength data - except angle of peak torque - demonstrated moderate-to-high reliability, with intraclass correlation coefficients (ICC) higher than 0.86. The highest reliability was observed for concentric peak torque of the knee extensor muscles (ICC = 0.99). Test-retest reliability of fatigue variables was moderate for the knee extensor (ICC range 0.84-0.89) and insufficient-to-moderate for the knee flexor muscles (ICC range 0.78-0.81). The more reliable index of muscle fatigue was the linear slope of the decline in work output. These findings establish the reliability of isokinetic and isometric measurements using the Con-Trex machine.     

Concentric Internal and Eccentric External Fatigue Resistanc of the Shoulder Rotator Muscles in Female Tennis Players

Background

Shoulder muscle imbalance is a potential shoulder injury risk factor in athletes performing overhead sports. While normative functional peak strength of concentric external to concentric internal shoulder muscle fatigue data is available, comparisons of functional eccentric external to concentric internal shoulder rotator muscle fatigue resistance, which impacts muscle imbalance throughout the duration of play, have not been studied in this population.

Objectives

To assess fatigue resistance of the internal and external shoulder rotator muscles in female tennis players.

Methods

Fifteen female collegiate tennis players were tested bilaterally for shoulder concentric internal and eccentric external peak torque production throughout 20 maximal repetitions on a Kin-Com isokinetic dynamometer. Twelve t - tests were conducted to evaluate for differences in peak torque, relative fatigue ratios, and functional peak torque ratios between extremities and mode of activation during the first, as well as, last five repetitions that were conducted.

Results

Non-dominant concentric internal and eccentric external peak torque production significantly decreased throughout the twenty repetitions. Neither dominant concentric internal peak torque decrements and eccentric peak torque decrements were not significantly different across the twenty contractions.These changes in peak torque upon subsequent repetitions resulted in relative fatigue ratios of dominant eccentric external rotation that were significantly greater than non-dominant eccentric external rotation. Relative fatigue ratios of dominant concentric internal rotation did not differ from non-dominant concentric internal rotation.

Conclusions

The data suggest that eccentrically activated external shoulder rotator muscles could possibly adapt to overhead activities by becoming more fatigue resistant.     

Isometric torque of the quadriceps femoris after concentric, eccentric and isometric training

Twenty-seven normal, healthy women participated in this study, which investigated three methods of increasing the isometric strength of the quadriceps femoris through a six-week training program. Three experimental exercise groups were formed: A, eccentric, B, concentric, and C, isometric. The peak isometric torque of the quadriceps femoris was determined on the Cybex II Isokinetic Dynamometer before and after training. A total of 18 exercise sessions per subject were held. A two-way ANOVA with repeated measures revealed that while all three experimental groups significantly increased in isometric strength, no one method of training was superior. No interaction occurred in the population between the effects of pre- and posttraining scores and the type of training. The relationship between the experimental design and knee joint biomechanics may have precluded significant differences in strength gain among the experimental groups.     

Reliability of isokinetic ankle dorsiflexor strength measurements in healthy young men and women

The purposes of this study were: (i) to determine the test-retest reliability of isokinetic ankle dorsiflexor strength measurements in young healthy adults using the Biodex dynamometer, and (ii) to examine several statistical measures for the interpretation of reliability. Thirty men and women (mean age 23 +/- 3 years) performed three maximal concentric contractions at 30 degrees/s, 60 degrees/s, 90 degrees/s, 120 degrees/s and 150 degrees/s. Reliability of peak torque, work and torque at a specific time were assessed by calculating the intraclass correlation coefficient (ICC 2,1), Pearson product moment correlation coefficient (r), standard error of the measurement (SEM), method error (ME) and coefficient of variation (CV), and by plotting the differences between observations against their means. Isokinetic tests of ankle dorsiflexor strength in healthy young adults using the Biodex dynamometer were highly reliable (ICC 0.61-0.93). It is recommended that test-retest reliability analyses include the ICC and assessments of measurement errors (SEM, ME or CV), as well as graphs to indicate any systematic variations in the data.     

What change in isokinetic knee muscle strength can be detected in men and women with hemiparesis after stroke?

OBJECTIVE: To assess the intra-rater (between occasions) test-retest reliability of isokinetic knee muscle strength measurements in subjects with chronic poststroke hemiparesis and to define limits for the smallest change that indicates real (clinical) improvements for stroke patients. SUBJECTS: Fifty men and women (mean age 58 +/- 6.4 years) 6-46 months post stroke, able to walk at least 300 m with or without a unilateral assistive device. METHODS: Maximal concentric knee extension and flexion contractions at 60 degrees/s and 120 degrees/s, and maximal eccentric knee extension contractions at 60 degrees/s, with the paretic and nonparetic limbs, were performed seven days apart using a Biodex dynamometer. MEASURES: Reliability of the maximum peak torque measurements was evaluated with the intraclass correlation coefficient (ICC(2,1)), the Bland and Altman analyses, the standard error of measurement (SEM and SEM%) and the smallest real difference (SRD and SRD%). RESULTS: Test-retest agreements were high (ICC(2,1) 0.89-0.96) with no discernible systematic differences between limbs, angular velocities and modes. The SEM%, representing the smallest change that indicates a real (clinical) improvement for a group of subjects, was relatively small (8-20%). The SRD%, representing the smallest change that indicates a real improvement for a single subject ranged from 26% to 33% for concentric knee extension, from 39% to 55% for concentric knee flexion, and from 22% to 25% for eccentric knee extension. CONCLUSION: Isokinetic knee muscle strength can be reliably measured and used to detect real improvements following an intervention for single subjects as well as for groups of subjects with chronic mild to moderate hemiparesis after stroke.     

Shoulder isokinetic profile of male handball players of the Brazilian National Team

Background

Data obtained on an isokinetic dynamometer are useful to characterize muscle status and have been reported in muscle imbalance studies in different types of sport. However, few studies have assessed elite handball players to establish reference values.

Objective

The purpose of this study was to compare, for the dominant (D) and non-dominant (ND) side, the isokinetic profile of shoulder rotator muscle strength between male handball players (H) and asymptomatic non-athletes (NA).

Method

Isokinetic concentric and eccentric strength tests for D upper limbs were performed by the H group (n=20) and the NA group (n=12). Internal and external rotator muscle peak torque in concentric action was assessed at 60°/s and 300°/s and in eccentric action at 300°/s. We also calculated conventional balance (the ratio of external rotator peak torque to internal rotator peak torque in concentric action) and functional balance (the ratio of external rotator peak torque in eccentric action to internal rotator peak torque in concentric action).

Results

In the H group, dominant limbs were stronger in concentric action for external rotation at 60 and 300°/s. The conventional balance ratio for the D side was significantly lower at 60 and 300°/s for H compared to NA. The functional ratio for the D side was significantly lower at 300º/s for H compared to NA.

Conclusions

Compared to asymptomatic non-athletes, handball players presented significant muscular imbalance resulting from daily sports practice, a known risk factor for shoulder injuries.     

Test-retest reliability of isokinetic muscle strength of the lower extremities in patients with stroke

OBJECTIVE: To i the test-retest reliability of isokinetic strength measurements of 3 muscle groups of the lower extremities in stroke patients. DESIGN: Isokineth tests of bilateral hip flexors, knee extensors, and ankle plantarflexors at 2 angular velocities, performed during 2 sessions scheduled 1 week apart for each subject. SETTING: Outpatilitation clinic of a local hospital in Taiwan. PARTICIPANTS: Nts with mild spastic hemiparesis secondary to stroke and with poststroke onset time of at least 6 months. All subjects could communicate and voluntarily move the affected lower extremity. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The maximal peak torque, total work, and average power of the 3 muscle groups on the affected side examined during each test were quantified by using the normalization and the deficit methods. The normalization method divides the measured strength value by the patient's body weight, whereas the deficit method divides the difference between the strengths of the unaffected and affected extremities by the strength of the unaffected extremity. RESULTS: The normalized strength measures for muscles on the affected side showed good to excellent test-retest reliability (intraclass correlation coefficient [ICC] range,.62-.94; P<.05), whereas the deficit strength measures did not always show good reliability (ICC range,.13-.91). The knee extensors and ankle plantarflexors, but not the hip flexors, on the affected side showed better test-retest reliability of isokinetic strength generated at faster velocity (ICC range,.73-.94) than that generated at slower velocity (ICC range,.62-.88). The normalized peak torque (ICC range,.76-.94) and total work (ICC range,.83-.91) were more reliable than the normalized average power (ICC range,.62-.90) for all 3 muscle groups on the affected side. CONCLUSIONS: Quantitative assessment of muscle strength of the affected lower extremity in patients with mild spastic hemiparesis secondary to stroke is feasible using isokinetic testing. However, the test-retest reliability of isokinetic strength measures is affected by the quantifying method, testing velocity, and strength measures.     

Leg press exercise can reduce functional hamstring:quadriceps ratio in the elderly

The aim of this study was to investigate whether 12 weeks of leg press strength training exercise could affect the conventional and functional hamstring:quadriceps ratios in the elderly. Twelve elderly participants were submitted to a 12 week progressive training protocol (two sessions/week) using a 45° leg press exercise. A significant increase in the one repetition maximum was observed after 4, 8, and 12 weeks (p = 0.001, p < 0.001, and p < 0.001, respectively) compared to week 0 and after 8 (p = 0.011) and 12 weeks (p = 0.001) compared to week 4. The concentric knee extensor peak torque was significantly higher at weeks 8 (p = 0.001) and 12 (p = 0.024) compared to week 0. There was no change in the concentric and eccentric knee flexor peak torques (p = 0.629 and 0.274, respectively) and conventional ratio (p > 0.314) after 12 weeks of training. The functional ratio (eccentric knee flexor peak torque:concentric knee extensor peak torque) reduced significantly after 8 (p = 0.034) and 12 (p = 0.036) weeks of strength training. Although the 45° leg press exercise requires knee extensor and flexor, hip extensor, and plantar flexor muscle strength, our findings suggest that the isolated use of the 45° leg press exercise reduces the knee functional ratio after 8 weeks of training. Therefore, 45° leg press exercise alone, without a hamstring exercise, should not be recommended for elderly individuals.     

Evolution of the isokinetic torque of shoulder rotators before and after 3 months of shoulder stabilization by the Latarjet technique]

OBJECTIVE: To compare prospectively isokinetic shoulder strength before and 3 months after shoulder stabilization by the Latarjet procedure indicated for the treatment of recurrent dislocation. METHOD: Twenty-five subjects, 23+/-6 years old, with anterior unidirectional recurrent shoulder dislocation, underwent isokinetic concentric (con) and eccentric (ecc) measurement of lateral rotators (LR) and medial rotators (MR) of both shoulders at the angular speed of 60 and 120 degrees par second. Evaluation was carried out in the scapular plane with the patient in a sitting position one month before and 3 months after shoulder stabilization by the Latarjet technique. We calculated the concentric ratio LR/MR and mixed ratios LR(ecc)/MR(con) and LR(con)/MR(ecc). RESULTS: Before surgery, the rotator peak torque for the operated shoulder side was similar to that of the healthy shoulder side. The concentric ratio for the healthy shoulder side was higher because the lateral rotators were slightly weaker on the recurrent-dislocated shoulder side. Three months after shoulder stabilization by the Latarjet technique, for the operated shoulder side, the isokinetic concentric torque of rotators was similar to that before surgery. For the operated shoulder side, only the eccentric torque of medial rotators was significantly lower after surgery than before surgery and lower than that for the healthy shoulder side (9 to 15%). Ratios did not differ before and after surgery. CONCLUSION: Three months after surgery with Latarjet technique for recurrent dislocated shoulder, operated shoulders showed a slight strength deficit as compared with healthy shoulders. The concentric deficit after surgery was not significantly different from that before surgery. This result could be explained by strengthening exercises performed during the shoulder rehabilitation program. However, the eccentric strength deficit of medial rotators of the operated shoulder is certainly associated with the opening and stitching of the sub-scapular muscle necessary for the shoulder stabilization.     

Tai Chi Chuan to improve muscular strength and endurance in elderly individuals: a pilot study

OBJECTIVE: To evaluate the training effect of a Tai Chi Chuan (TCC) program on knee extensor muscular strength and endurance in elderly individuals. DESIGN: Before-after trial. SETTING: Community setting. PARTICIPANTS: Forty-one community dwelling subjects aged 61.1 +/- 9.8 years undertook a TCC program. Nine dropped out during the study. Pretraining and posttraining measurements were obtained from 15 men and 17 women. INTERVENTION: Subjects participated in a 6-month TCC program. Each session consisted of 20 minutes of warm-up, 24 minutes of structured TCC training, and 10 minutes of cool-down exercises. MAIN OUTCOME MEASURES: Peak torque of dominant and nondominant knee extensors was tested at speeds of 60 degrees , 180 degrees , and 240 degrees/sec concentrically and eccentrically. Muscular endurance of the knee extensor was tested at the speed of 180 degrees /sec. RESULTS: In the group of men, concentric knee extensor peak torque increased by 15.1% to 20.0% and eccentric peak torque increased by 15.1% to 23.7%. The group of women also showed increases, ranging from 13.5% to 21.8% in concentric peak torque, and 18.3% to 23.8% in eccentric peak torque. In addition, the knee extensor endurance ratio increased by 9.6% to 18.8% in the men and 10.1% to 14.6% in the women. CONCLUSION: TCC training may enhance muscular strength and endurance of knee extensors in elderly individuals.     

Isokinetic eccentric training is more effective than constant load eccentric training for quadriceps rehabilitation following anterior cruciate ligament reconstruction: a randomized controlled trial

ObjectiveTo compare the effects of conventional (constant load) eccentric training and isokinetic eccentric training on quadriceps muscle mass, strength and functional performance in recreational athletes following anterior cruciate ligament (ACL) reconstruction.MethodsThirty recreational male athletes (25 years old) undergoing ACL reconstruction received a standard rehabilitation program. Volunteers were randomized to conventional group (CG; n = 15) or isokinetic group (IG; n = 15) to be engaged in a 6-week (2 sessions/week) quadriceps eccentric training program at the extensor chair or at the isokinetic dynamometer, respectively. Assessments of quadriceps muscle mass (through magnetic resonance imaging), strength (through isokinetic dynamometry) and self-aware functionality (through questionnaire) were performed before and after the training programs. Single leg hop test performance was assessed only at post-training evaluation.ResultsIG had significantly higher improvements than CG (p < 0.05) for all muscle mass outcomes (+17–23% vs. +5–9%), as well as for isometric (+34% vs. +20%) and eccentric (+85% vs. +23%) peak torques. There was no between-group difference (p > 0.05) for concentric peak torque, Lysholm score, and single leg hop test.ConclusionIsokinetic eccentric training promotes greater responses than conventional eccentric training on quadriceps muscle mass and strength of recreational athletes following ACL reconstruction.     

Pain-related factors contributing to muscle inhibition in patients with chronic low back pain: an experimental investigation based on superimposed electrical stimulation

OBJECTIVE: To evaluate muscle strength, as a component of physical deconditioning, and central activation ratio, representing the performance level during testing, in patients with chronic low back pain as compared to healthy controls, and to evaluate the contribution of cognitive-behavioral and pain-related factors to the central activation ration of patients with chronic low back pain. METHODS: Twenty-five patients with chronic low back pain and 25 age and gender-matched controls participated. Muscle strength, that is, peak torque of the quadriceps muscle, was measured on a Cybex dynamometer. During peak torque, the quadriceps muscle was percutaneously stimulated using superimposed electrical stimulation, generating an additional twitch torque in case of submaximal performance. The central activation ratio was calculated as peak torque/(peak torque + additional twitch torque). To evaluate cognitive-behavioral and pain-related factors influencing the central activation ratio, measures of fear of injury, pain catastrophizing, psychologic distress, and pain intensity were used. Differences between groups were tested using either T tests or Mann-Whitney U tests. Associations were tested by partial correlation coefficients controlling for gender. RESULTS: The male:female ratio was 15:10. Mean age and chronic low back pain duration were 42.7 (+/-9.5) and 9.9 (+/-8.3) years, respectively. Mean muscle torque (per kg lean body mass) in patients (1.95 Nm/kg +/-0.8) was less than in controls (3.16 Nm/kg +/-0.7) (P < 0.01). Median central activation ratio was lower in patients (P < 0.05). Patients experiencing increased psychologic distress and patients with a higher current pain level showed a lower central activation ratio (P < 0.05). CONCLUSIONS: When interpreting decreased muscle strength in terms of physical deconditioning in patients with chronic low back pain, submaximal performance has to be taken into account. The results suggest that patients with chronic low back pain who report increased psychologic distress and a higher level of current pain tend to show increased inhibition of muscle activity, leading to submaximal performance.     

股四头肌绳肌等速肌力测试的效度研究

了解Ｃｙｂｅｘ３３０型等速功能评定装置是否能有效反映肌力。方法：按骨骼肌肌力与总的肌纤维横断面积成比例的特性，选用ＣＴ成像技术测量产力肌的横断面积和ＣＴ值，对抽测的绳肌和股四头肌的峰值转矩、面积和ＣＴ值进行对比研究。结果：①所有受试者诸肌的各峰值转矩与面积的相关系数为０．４８－０．８０，相关均有显著性或非常显著性；②正常人所测肌的各峰转矩与ＣＴ值的相关系数为０．０２－０．５０，相关均无显著性；③患者除股四头肌在３００°／ｓ运动时峰值转矩与Ｃ４值的相关无显著性外，其余各峰值转矩与ＣＴ值的相关系数为０．４６－０．６１，相关有显著性或非常显著性；④在正常人中，虽然上述指标大多数为优势侧大于非优势侧，但双侧差异均无显著性，而患者健侧的各项指标均大于患侧，差异有显著性和非常显著性。结论：用此装置所测试的等速肌力符合产力肌肉横断面积的变化，他不仅能有效地评定肌力，而且能反映用徒手肌力测试观察不到的肌力变化，可以作为客观评定临床和康复治疗效果及康复医学等研究的工具。     

Evaluation of a dynamometer measuring torque of uni- and bilateral concentric and eccentric muscle action

Summary. A dynamometer designed for torque measurements of uni- and bilateral concentric and eccentric muscle actions of the quadriceps and hamstring muscle groups is described. Torque reproducibility and control of lever-arm position were studied using known standards. In vivo measurements assessed angular velocity, lever-arm acceleration, variability of torque between limbs and reproducibility of torque. Torque obtained from left and right leg attachments was equal when using weights and during dynamic in vivo conditions. Static torque recorded at different lever-arm positions and known torque were equal. Likewise, lever-arm position output equated with known angles. In vivo test-retest of peak torque was found to be reliable. Acceleration of the lever arm was greater for concentric bilateral than for unilateral muscle actions but equal during eccentric muscle actions. The dynamometer is suggested to provide valid and reproducible torque measurements up to at least 700 Nm at constant angular velocities up to 2·62 rad s^-1. Besides being a research tool the dynamometer is useful in clinical settings for rehabilitation and evaluation of skeletal muscle function.