老年人膝关节和踝关节位置觉的重测信度

背景：目前国内外关节位置觉的研究主要以青年人为对象,而老年人在不同角度关节位置重现的重测信度研究比较缺乏。目的：观察老年人膝关节和踝关节在不同角度关节复位测试的重测信度。方法：在Biodex system 3等速系统上用被动复位测试法测试28名健康老年人的膝、踝关节本体感觉,以被动复位绝对误差角度作为个体位置觉能力优劣的代表。重测信度评价指标为组内相关系数（ICC）。结果与结论：左右两侧膝关节位置觉测试在不同角度都具有良好的重测信度,ICC值为0.851～0.973;左右两侧踝关节位置觉测试在跖屈与背伸位具有中等以上的重测信度,ICC值为0.742～0.964;左侧踝关节复位的绝对误差角度小于右侧踝关节（P〈0.05）,且左侧（ICC为0.870～0.964）踝关节重测的相关系数高于右侧（ICC为0.742～0.944）。提示老年人膝关节和踝关节位置觉重测的相关性良好,并且左侧踝关节的相关性高于右侧。     

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.     

Jamar握力器对老年男性的重测信度和测量误差

目的分析Jamar握力器在老年人握力测量时的重测信度和测量误差。方法40位老年志愿者,平均年龄(82.2±8.4)岁。接受间隔1周共2次Jamar握力器测量握力。结果组内相关系数为0.99。测量标准误(SEM、SEM%)为1.18～1.69、4.11%～6.41%;个案最小真实改善程度值(SRD、SRD%)为3.27～4.68、11.39%～17.75%;Bland-Altman分析显示没有系统误差。结论在老年男性中,Jamar握力器具有良好的重测信度与可接受的测量误差。     

老年人膝关节和踝关节位置觉的重测信度

背景:目前国内外关节位置觉的研究主要以青年人为对象,而老年人在不同角度关节位置重现的重测信度研究比较缺乏.目的:观察老年人膝关节和踝关节在不同角度关节复位测试的重测信度.方法:在Biodex system 3等速系统上用被动复位测试法测试28名健康老年人的膝、踝关节本体感觉,以被动复位绝对误差角度作为个体位置觉能力优劣的代表.重测信度评价指标为组内相关系数(ICC).结果与结论:左右两侧膝关节位置觉测试在不同角度都具有良好的重测信度,ICC值为0.851~0.973;左右两侧踝关节位置觉测试在跖屈与背伸位具有中等以上的重测信度,ICC值为0.742~0.964;左侧踝关节复位的绝对误差角度小于右侧踝关节(P < 0.05),且左侧(ICC为0.870~0.964)踝关节重测的相关系数高于右侧(ICC为0.742~0.944).提示老年人膝关节和踝关节位置觉重测的相关性良好,并且左侧踝关节的相关性高于右侧.     

Test-retest reliability of cervicocephalic kinesthetic sensibility in three cardinal planes

The test-retest reliability of both the head-to-neutral head position (NHP) and head-to-target repositioning tests in three cardinal planes has been examined in this study. Twenty young adults underwent both head repositioning tests and retests with 10 min rest intervals. Root mean square error (RMSE, total error), constant error (CE, directional bias), variable error (VE, variability), and standard error of measurement (SEM) were calculated from the position data recorded by an ultrasound-based motion analysis system. Intra-class correlation coefficients (ICC) were used to examine reliability. The results showed fair to excellent reliability of RMSE during head-to-NHP (ICC=0.45-0.80) and head-to-target tests (ICC=0.42-0.90), except during the head-to-NHP test (ICC=0.29) from a head extended position. Low reliability of VE associated with the neck motion toward left side bending indicated a direction-dependent effect. The SEM of RMSE (0.7-2.6 degrees), CE (0.3-4.0 degrees) and VE (0.4-1.5 degrees) indicated an acceptable range of error. The present study indicated acceptable and reliable RMSE measurements with a motion analysis system in healthy young adults. Furthermore, examining the CE and VE could contribute to the interpretation of whether the subject performed the reposition tests with directional bias and repositioning variability, respectively.     

Reliability of ankle dorsiflexion passive range of motion measurements obtained using a hand-held goniometer and Biodex dynamometer in stroke patients

[Purpose] This study investigated the reliability of ankle dorsiflexion passive range of motion (DF-PROM) measurements obtained using a goniometer and Biodex dynamometer in stroke patients. [Subjects] Fifteen stroke patients participated in this study. [Methods] Ankle DF-PROM was assessed using a goniometer and Biodex dynamometer. Ankle DF-PROM was measured during two sessions with 7 days between tests. Intraclass correlation coefficient, standard error of measurement, and minimal detectable change values were used to assess the reliability of measurements obtained using both instruments. [Results] The intra-rater reliability for ankle DF-PROM using the goniometer was moderate and good for the two raters, while using the Biodex dynamometer, it was good for both raters. Inter-rater reliability using the goniometer was moderate; using the Biodex, it was good. [Conclusion] Both intra- and inter-reliability measurements of ankle DF-PROM were higher using a Biodex dynamometer than with a goniometer.Key words: Biodex reliability, Ankle dorsiflexion passive range of motion, Stroke     

Reliability of isokinetic measurements of hip muscle torque in young boys

The purpose of this study was to determine the reliability of measurements of hip muscle torque obtained with the Cybex II isokinetic dynamometer from healthy young boys. Twenty-nine healthy boys, aged 6 to 10 years, were tested two times at one- to two-week intervals. Torque of the hip flexors and extensors and the hip abductors and adductors was assessed at angular velocities of 30 degrees and 90 degrees/sec. The torque generated by each muscle group at 30 degrees/sec was similar to the torque generated at 90 degrees/sec. Intraclass correlation coefficients (ICCs) were used to determine test-retest reliability for measurements of each of the muscle groups at both angular velocities. The ICCs were higher for hip flexion and extension than they were for hip abduction and adduction. The highest ICC (ICC = .84) was found for hip extension at 90 degrees/sec. The ICCs for hip abduction and adduction at both angular velocities were less than .60. Factors that possibly contributed to the relatively low reliability in hip abduction and adduction are discussed.     

Reliability of hand-held dynamometry and functional strength tests for the lower extremity in children with Cerebral Palsy

PURPOSE: To evaluate the intertester reliability of two methods for measuring lower-limb strength in children with cerebral palsy (CP). METHOD: Twenty-five subjects with CP (7-17 years of age) participated in this study. Lower-limb muscle strength was measured on 2 occasions using a Hand-held Dynamometer (HHD; break-method and make-method) and a 30-sec Repetition Maximum (RM) during three functional strength tests for the lower extremities. Reliability was measured using the intraclass correlation coefficients (ICCs), the standard error of measurement (SEM) and the coefficient of variation (CV). RESULTS: The intertester reliability of strength measurement using a HHD was questionable with ICC values ranging from 0.42-0.73 for the break-method, and from 0.49-0.82 for the make-method. The SEM and CV (%) values ranged from 27.9-58.9 and 22.2-35.3% for the break-method, and from 30.6-52.7 and 16.2-56.2% for make-method. The intertester reliability of strength measurement using the 30-sec RM was acceptable with ICC values ranging from 0.91 -0.96, and SEM and CV (%) values ranging from 1.1-2.6 and 10.9-39.9% for the functional exercises. CONCLUSION: The intertester reliability of measuring muscle strength of the lower extremities using a hand-held dynamometer is questionable. The intertester reliability of the 30-sec RM for the lower extremity is acceptable.     

Reliability of isokinetic strength imbalance ratios measured using the Cybex NORM dynamometer

The main aim of this study was to examine the absolute and relative reliability of some commonly used strength imbalance indices such as concentric hamstring-to-concentric quadriceps ratio, eccentric hamstring-to-concentric quadriceps ratio and bilateral concentric and eccentric strength ratios. An additional aim was to examine the reliability of the peak torque and work of the knee extensor and flexor muscles measured using the Cybex NORM dynamometer. Eighteen physically active healthy subjects (mean +/- standard deviation, age 23 +/- 3 years, height 176 +/- 5 cm, body mass 74 +/- 8 kg) were tested three times with 96 h between sessions. Peak torque, average work, unilateral and bilateral ratios were determined at 60, 120, 180 and -60 degrees s(-1). Low (0.34) to moderate (0.87) relative reliability (intraclass correlation coefficient, ICC) was found for strength imbalance ratios with eccentric hamstring-to-concentric quadriceps ratio showing the greater ICC (>0.80). High ICC values (0.90-0.98) were found for peak torque and average work. Absolute reliability (standard error of measurement) ranged from 3.2% to 8.7% for strength imbalance ratios and from 4.3% to 7.7% for peak torque and average work measurements. This study established the reliability of the most common strength imbalance ratios and of absolute isokinetic muscle strength assessed using the Cybex NORM.     

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.     

Reliability of hand-held dynamometry and functional strength tests for the lower extremity in children with Cerebral Palsy

Purpose. To evaluate the intertester reliability of two methods for measuring lower-limb strength in children with cerebral palsy (CP).

Method. Twenty-five subjects with CP (7 – 17 years of age) participated in this study. Lower-limb muscle strength was measured on 2 occasions using a Hand-held Dynamometer (HHD; break-method and make-method) and a 30-sec Repetition Maximum (RM) during three functional strength tests for the lower extremities. Reliability was measured using the intraclass correlation coefficients (ICCs), the standard error of measurement (SEM) and the coefficient of variation (CV).

Results. The intertester reliability of strength measurement using a HHD was questionable with ICC values ranging from 0.42 – 0.73 for the break-method, and from 0.49 – 0.82 for the make-method. The SEM and CV (%) values ranged from 27.9 – 58.9 and 22.2 – 35.3% for the break-method, and from 30.6 – 52.7 and 16.2 – 56.2% for make-method. The intertester reliability of strength measurement using the 30-sec RM was acceptable with ICC values ranging from 0.91 – 0.96, and SEM and CV (%) values ranging from 1.1 – 2.6 and 10.9 – 39.9% for the functional exercises.

Conclusion. The intertester reliability of measuring muscle strength of the lower extremities using a hand-held dynamometer is questionable. The intertester reliability of the 30-sec RM for the lower extremity is acceptable.     

Test-retest reliability of hand-held dynamometric strength testing in young people with cerebral palsy

OBJECTIVE: To evaluate the test-retest reliability of measuring lower-limb strength with a hand-held dynamometer in young people with cerebral palsy (CP). DESIGN: One rater measured the isometric strength of the lower limbs in 10 participants with CP on 2 occasions separated by 6 weeks. SETTING: University movement rehabilitation laboratory in Australia. PARTICIPANTS: Ten young people (mean age +/- standard deviation, 13.5+/-3.4 y) with spastic diplegic CP. Eight of the participants walked independently and 2 walked with assistive devices. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Retest reliability of lower-limb strength, expressed in the units of measurement for the interpretation of group mean and individual scores and as intraclass correlation coefficients (ICC(2,1)). RESULTS: For groups, mean lower-limb strength increases of 7 kg (30%) could be interpreted as real change using 95% confidence intervals (CIs). For individuals, for strength gains to be interpreted as real change using 95% CIs, strength increases would need to be greater than 16.8 kg (70%) for the measurement of knee extension and to be greater than 4.3 kg (25%) for ankle plantarflexion. Measurement of hip extension strength was not reliable for group mean or individual scores. All reliability coefficients were greater than.80. CONCLUSION: A hand-held dynamometer can reliably measure changes in lower-limb strength for groups of young people with CP. It is uncertain whether this method is useful for evaluating change in individuals. Relying only on a coefficient of reliability to decide the usefulness of a measurement can be misleading.     

STRENGTH AND FATIGUE MEASUREMENTS OF THE HIP FLEXOR AND HIP EXTENSOR MUSCLES: TEST-RETEST RELIABILITY AND LIMB DOMINANCE EFFECT

Background:Standardized testing of hip muscle strength and fatigue in the sagittal plane is important for assessing, treating and preventing a number of trunk and lower extremity pathologies. Furthermore, individuals displaying asymmetries of muscle strength between limbs are more likely to sustain an injury.Purpose:To evaluate the test-retest reliability of isometric strength and isokinetic fatigue measurements of the hip flexor and hip extensor muscles, and to examine whether there is a significant limb dominance effect on strength, fatigue and flexor-extensor ratios.Study design:Cross-sectional study.Methods:To evaluate reliability, 30 healthy individuals (33.2 + /- 13.1 years) were included. On a separate occasion, 24 healthy individuals (29.0 + /- 10.3 years) participated to assess between-limb differences. Reliability was established using intraclass correlation coefficients (ICCs), standard error of measurements (SEM) and minimal detectable change (MDC). Isometric strength (best peak torque of three maximal contractions; Nm/kg), isokinetic fatigue (total work of 20 consecutive maximal concentric flexor-extensor contractions at 120 °/s; Joule/kg), and flexor-extensor ratios, were recorded using a Biodex dynamometer.Results:Reliability was good-to-excellent (ICCs>0.83) and measurement errors were acceptable (SEM<13.6% and MDC%<37.8%). No significant between-limb differences in strength, fatigue and flexor-extensor ratios were detected.Conclusions:Isometric strength and isokinetic fatigue of the hip flexor and hip extensor muscles can be reliably assessed in healthy individuals using the Biodex dynamometer. Limb dominance did not significantly affect strength, fatigue or flexor-extensor ratios.Level of Evidence:2b     

Comparison of Common Methodologies for the Determination of Knee Flexor Muscle Strength

BackgroundKnee flexion strength may hold important clinical implications for the determination of injury risk and readiness to return to sport following injury and orthopedic surgery. A wide array of testing methodologies and positioning options are available that require validation prior to clinical integration. The purpose of this study was to 1) investigate the validity and test-retest reliability of isometric knee flexion strength measured by a fixed handheld dynamometer (HHD) apparatus compared to a Biodex Dynamometer (BD), 2) determine the impact of body position (seated versus supine) and foot position (plantar- vs dorsiflexed) on knee flexion peak torque and 3) establish the validity and test-retest reliability of the NordBord Hamstring Dynamometer.Study DesignValidity and reliability study, test-retest design.MethodsForty-four healthy participants (aged 27 ± 4.8 years) were assessed by two raters over two testing sessions separated by three to seven days. Maximal isometric knee flexion in the seated and supine position at 90^o knee flexion was measured with both a BD and an externally fixed HHD with the foot held in maximal dorsiflexion or in plantar flexion. The validity and test-retest reliability of eccentric knee flexor strength on the NordBord hamstring dynamometer was assessed and compared with isometric strength on the BD.ResultsLevel of agreement between HHD and BD torque demonstrated low bias (bias -0.33 Nm, SD of bias 13.5 Nm; 95% LOA 26.13 Nm, -26.79 Nm). Interrater reliability of the HHD was high, varying slightly with body position (ICC range 0.9-0.97, n=44). Isometric knee flexion torque was higher in the seated versus supine position and with the foot dorsiflexed versus plantarflexed. Eccentric knee flexion torque had a high degree of correlation with isometric knee flexion torque as measured via the BD (r=0.61-0.86). The NordBord had high test-retest reliability (0.993 (95%CI 0.983-0.997, n=19) for eccentric knee flexor strength, with an MDC₉₅ of 26.88 N and 28.76 N for the left and right limbs respectively.ConclusionCommon measures of maximal isometric knee flexion display high levels of correlation and test-retest reliability. However, values obtained by an externally fixed HHD are not interchangeable with values obtained via the BD. Foot and body position should be considered and controlled during testing.Level of Evidence2b     

Learning effect of isokinetic measurements in healthy subjects, and reliability and comparability of Biodex and Lido dynamometers

The aim of this study was to examine the learning effect during a set of isokinetic measurements, to evaluate the reliability of the Biodex System 3 PRO dynamometer, and to compare the Biodex System 3 PRO and the Lido Active dynamometers on both extension and flexion over the elbow and the knee at 60 degrees s(-1). Thirteen (nine women, four men) healthy participants were measured five times using the Biodex and once using the Lido dynamometer. The intervals between the first four tests were 20 min, and 1 week between tests 4 and 5. Between Biodex and Lido measurements there was a 20 min time interval. When comparing the first five measurements (Biodex), no systematic effect over time and an excellent reliability were found with respect to elbow and knee flexion and extension. No difference in muscle strength (Nm) between the Biodex and Lido was observed for knee flexion (P = 0.59), knee extension (P = 0.18) and elbow extension (P = 0.63). However, elbow flexion showed a 14.8% (95% CI: 11.2-18.4%; P = 0.0001) higher peak torque on Biodex. In conclusion, no learning effect was observed and the Biodex proved to be a highly reliable isokinetic dynamometer. A difference was observed when comparing Biodex and Lido on elbow flexion, but the difference did not outrange the expected variation found with a typical isokinetic measurement, which is why both sets of equipment seem applicable in clinical practice.     

Reliability of simple portable tests of physical performance in older people after hip fracture

OBJECTIVE: To investigate the test-retest reliability of measures of strength, balance, gait and functional performance when used with older people following hip fracture. SUBJECTS: Thirty people (16 hospital inpatients and 14 community dwellers). DESIGN: Subjects underwent two assessments: one day apart for the hospital inpatients and one week apart for the community dwellers. MEASUREMENT: Strength (dynamometer, sphygmomanometer, spring balance, lateral step-up ability), balance (sway-meter, Functional Reach Test, single leg stance time, Step Test), gait (timed 6-m walk with steps taken, base of support and step length), and functional performance (PPME total score and timed supine-to-sit and sit-to-stand) were measured. RESULTS: Eleven of the 14 continuously scaled measurement tools achieved excellent reliability (intraclass correlation coefficient (ICC) > 0.75) for one or more tests. A hand-held dynamometer was found to be the tool with the highest test-retest reliability for measuring hip muscle strength (ICC (3,1) 0.86 for affected hip abduction). For measurement of knee extension strength, a spring balance (ICC (3,1) 0.94 affected leg) was the most reliable. For testing balance, the Step Test (ICC (3,1) 0.94 for stepping with affected leg) and Functional Reach Test (ICC (3,1) 0.89) had the highest test-retest reliability. The ICC (3,1) values were 0.97 for walking velocity (comfortable pace) and 0.96 for the total score of the Physical Performance and Mobility Examination. CONCLUSION: The test-retest reliability of a number of simple measures of physical performance is excellent when used with this population.     

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.     

Reliability and validity of ankle proprioceptive measures

OBJECTIVE: To determine the reliability and validity of ankle proprioceptive measures. DESIGN: Reliability was assessed between test occasions. Construct validity was addressed by the ability of measures to differentiate among groups. SETTING: Laboratory of an educational institution. PARTICIPANTS: Eight healthy adults were recruited into each of 3 groups: (1) young (20-39y), (2) middle-aged (40-59y), and (3) older adults (>or=60y). Four subjects from each group (n=12) participated in retesting. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Threshold for perception of passive movement, error in active reproduction of position, error in reproduction of velocity, and error in reproduction of torque. RESULTS: Intersession reliability was excellent (intraclass correlation coefficient [ICC] range, .79 - .95) for threshold for perception of movement, error in active reproduction, error in velocity reproduction, and error in dorsiflexion torque reproduction; intersession reliability was good for error in reproduction of plantarflexion torque (ICC=.72). Threshold for perception of movement differed between groups 1 and 3 and between groups 2 and 3 (P<.05). Error in reproduction of position was greater in group 2 than in group 1 (P<.05). CONCLUSION: Differences in proprioception between the older and the 2 younger groups were best detected by using threshold for perception of passive movement.     

Test-retest strength reliability: hand-held dynamometry in community-dwelling elderly fallers

OBJECTIVE: To determine the reliability of a standardized protocol by using a hand-held dynamometer (HHD) to measure lower-extremity strength in community-dwelling elderly fallers. DESIGN: Within-session test-retest reliability of the HHD. SETTING: Balance laboratory of a university. PARTICIPANTS: A convenience sample of 41 community-dwelling elders (61-90y) who fell at least once in the previous year. INTERVENTION: The strengths of 8 lower-extremity muscle groups bilaterally were tested twice, with an intervening rest period of 15 seconds. MAIN OUTCOME MEASURE: Maximal isometric force. RESULTS: Test-retest intraclass correlation coefficients (ICCs) were high, generally ranging from.95 to.99 for 1 trial (ICC(2,1)) and from.97 to 1.00 for the mean of 2 trials (ICC(2,2)). There were no significant differences in strength values across trials (P>.05). Men had significantly greater strength than women across all muscle groups (P>.05). Right knee extensor strength demonstrated the largest trial-to-trial difference,.54 kg using a single measurement and.39 kg using the mean of both measurements. Among the 3 lower-extremity muscle groups, the ankle showed higher a coefficient of variation (CV=5.1%-7.4%) than the knee (CV=4.6%-5.1%) or the hip (CV=4.2%-6.3%) when using 1 measure. CONCLUSION: By using an HHD and a standardized measurement protocol, a novice tester can obtain reliable lower-extremity strength values in community-dwelling elderly fallers.     

Test-retest reliability of isokinetic dynamometry for the assessment of spasticity of the knee flexors and knee extensors in children with cerebral palsy

OBJECTIVE: To assess test-retest reliability of the peak resistance torque and slope of work methods of spasticity measurement of the knee flexors and extensors in children with cerebral palsy (CP). DESIGN: Test-retest reliability study. SETTING: Pediatric orthopedic hospital. PARTICIPANTS: Fifteen children with CP. INTERVENTION: Knee extensor and flexor spasticity was assessed with an isokinetic dynamometer using passive movements at 15 degrees, 90 degrees, and 180 degrees/s taken 1 hour apart. MAIN OUTCOME MEASURES: Peak resistive torque and work were calculated. The relative and absolute test-retest reliability was calculated by using intraclass correlation coefficients (ICCs) and Bland-Altman plots, respectively. RESULTS: Relative reliability was good (ICC>.75) for slope-of-work and peak resistance torque measurements at a velocity of 180 degrees/s, whereas reliability of peak torque measurements was decreased (ICC<.51) at slower velocities for both muscle groups. The 95% limits of agreement of Bland-Altman plots contained most data points for both methods, but the width of the limits of agreement were wide. CONCLUSIONS: The measurement of spasticity of the knee extensors and flexors in children with CP using peak-resistance torque at 180 degrees/s and the slope of work method has acceptable relative test-retest reliability. However, the absolute reliability of spasticity data should be considered cautiously.