On the assessment of lower-limb muscular power capability (original) (raw)
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Reliability and Validity of Three Clinical Methods to Measure Lower Extremity Muscle Power
2021
Background: Lower extremity muscle power is critical for daily activities and athletic performance in clinical populations. Objective: The purpose of this study was to determine the reliability and validity of 3 clinically feasible methods to measure lower extremity muscle power during a leg press. Methods: Ten of 26 subjects performed 2 sessions of 5 submaximal leg presses separated by 3-7 days in this repeated-measures cross-sectional design; the remaining performed 1 test session. Power was calculated independently for each method [simple video, linear position transducer, and accelerometer] and compared to the reference force plate. Test-retest reliability was evaluated using intraclass correlation coefficients (ICC). Pearson's correlation coefficient (r), Bland-Altman plots with 95% limits of agreement (LOA), and mean bias percentages (%) were used to determine relative and absolute validity. Results: Power measures were reliable for all methods (ICC=.97-.99). All were highly correlated with the force plate (r=.96-.98). Mean bias was-0.8% (LOA:-16.57% to 14.98%) (video),-13.21% (LOA:-23.81% to-2.61%) (position transducer) compared to the force plate. Proportional bias was observed for accelerometry. Conclusion: All methods were reliable and highly correlated with the force plate. Only the video and position transducer demonstrated absolute validity. The position transducer was the most feasible method because of its simplicity and accuracy in measuring power.
Relative reliability of three objective tests of limb muscle strength
Isokinetics and exercise science, 2011
If measures of muscle strength are to be broadly applied, they should be objective, portable, quick, and reliable. Through this component of the NIH Toolbox study we sought to compare the test-retest reliability of 3 tests of muscle strength that are objective, portable, and quick: the five-repetition sit-to-stand test (FRSTST), hand-grip dynamometry (HGD), and belt-stabilized hand-held dynamometry (BSHHD) of knee extension. Three sets of each test were performed- 1 warm-up and 2 maximal. Measures from the maximal tests obtained 4 to 10 days apart were compared. Reliability was described using descriptive statistics, intraclass correlation coefficients (ICCs) and 4 measures of response stability: standard error of measurement (SEM), method error (ME), coefficient of variation of SEM (SEM CV ), and coefficient of variation of variation of ME (ME CV ). The ICCs of all tests were good (≥ 0.853). Measures of response stability showed less variability between test and retest for FRSTST a...
Applied Sciences
The 5-Sit-to-stand test (5STS) is used for lower limb muscle power (MP) determination in field/clinical setting. From the time taken to perform five standing movements and three partially verified assumptions (vertical displacement, mean concentric time, and mean force), MP is estimated as the body’s vertical velocity x force. By comparison with a gold standard, laboratory approach (motion capture system and force plate), we aimed to: (1) verify the assumptions; (2) assess the accuracy of the field-estimated MP (MPfield); (3) develop and validate an optimized estimation (MPfield-opt). In 63 older adults (67 ± 6 years), we compared: (i) estimated and measured assumptions (2-WAY RM ANOVA), (ii) MPfield and MPfield-opt with the reference/laboratory method (MPlab) (2-WAY RM ANOVA, Pearson’s correlation coefficient (r), Bland-Altman analysis). There was a significant difference between estimated and measured assumptions (p < 0.001). Following the implementation of the optimized assump...
Journal of Strength and Conditioning Research, 2010
Negrete, RJ, Hanney, WJ, Kolber, MJ, Davies, GJ, Ansley, MK, McBride, AB, and Overstreet, AL. Reliability, minimal detectable change, and normative values for tests of upper extremity function and power. J Strength Cond Res 24 : 3318-3325, 2010-The purpose of this study was to examine the test-retest reliability, minimal detectable change (MDC), and determine normative values of 3 upper extremity (UE) tests of function and power. One hundred eighty participants, men (n = 69) and women (n = 111), were tested on 3 UE strength and power maneuvers in a multicenter study to determine baseline normative values. Forty-six subjects returned for a second day of testing within 5 days of the initial assessment for the reliability component of the investigation. Explosive power was assessed via a seated shot-put test for the dominant and nondominant arms. Relationships between the dominant and nondominant arms were also analyzed. A push-up and modified pull-up were performed to measure the amount of work performed in short (15-second) bursts of activity. The relationship between the push-up and modified pull-up was also determined. Analysis showed test-retest reliability for the modified pull-up, timed push-up, dominant single-arm seated shot-put tests, and nondominant single-arm seated shot-put tests to be intraclass correlation coefficient (3,1) 0.958, 0.989, 0.988, and 0.971, respectively. The MDC for both the push-up and modified pull-up was 2 repetitions. The MDCs for the shot put with the dominant arm and the nondominant arm were 17 and 18 in., respectively. The result of this study indicates that these field tests possess excellent reliability. Normative values have been identified, which require further validation. These tests demonstrate a practical and effective method to measure upper extremity functional power.
Lower-Limb Power cannot be Estimated Accurately from Vertical Jump Tests
Journal of Human Kinetics, 2013
The countermovement jump test is often adopted to monitor lower-limb power of an individual. Despite several studies on the validity of this test, there is still a need to determine the minimal difference needed to be confident that a difference in power between two individuals is present or that a true change in the performance of an individual has occurred. In this study, power was measured from ground reaction forces and compared to that obtained from predictive equations for two groups of subjects (67 trained and 20 highly trained individuals). The height of each jump was determined with kinematic techniques. The main outcome is a large discrepancy between power calculated from ground reaction forces and that calculated from predictive equations. For the trained group, the R-square value between power and predicted power was 0.53 and the minimal difference to consider that two individuals were different was 821.7 W. For the highly trained individuals, a much larger R-square value was obtained (0.94). Despite this, the minimal difference to consider that two individuals were different was still large (689.3 W). The large minimal differences obtained raise serious concerns about using countermovement jumps for appraisal and monitoring of lower-limb power of an individual.
Reliability and Factorial Validity of Squat and Countermovement Jump Tests
Journal of Strength and …, 2004
Markovic, G., D. Dizdar, I. Jukic, and M. Cardinale. Reliability and factorial validity of squat and countermovement jump tests. J. Strength Cond. Res. 18(3):551-555. 2004.-The primary aim of this study was to determine reliability and factorial validity of squat (SJ) and countermovement jump (CMJ) tests. The secondary aim was to compare 3 popular methods for the estimation of vertical jumping height. Physical education students (n ϭ 93) performed 7 explosive power tests: 5 different vertical jumps (Sargent jump, Abalakow's jump with arm swing and without arm swing, SJ, and CMJ) and 2 horizontal jumps (standing long jump and standing triple jump). The greatest reliability among all jumping tests (Cronbach's ␣ ϭ 0.97 and 0.98) had SJ and CMJ. The reliability ␣ coefficients for other jumps were also high and varied between 0.93 and 0.96. Within-subject variation (CV) in jumping tests ranged between 2.4 and 4.6%, the values being lowest in both horizontal jumps and CMJ. Factor analysis resulted in the extraction of only 1 significant principal component, which explained 66.43% of the variance of all 7 jumping tests. Since all jumping tests had high correlation coefficients with the principal component (r ϭ 0.76-0.87), it was interpreted as the explosive power factor. The CMJ test showed the highest relationship with the explosive power factor (r ϭ 0.87), that is, the greatest factorial validity. Other jumping tests had lower but relatively homogeneous correlation with the explosive power factor extracted. Based on the results of this study, it can be concluded that CMJ and SJ, measured by means of contact mat and digital timer, are the most reliable and valid field tests for the estimation of explosive power of the lower limbs in physically active men.
An evaluation of a strength qualities assessment method for the lower body
The purpose of this investigation was to evaluate an assessment method for the lower body and its ability to detect training induced changes in athletes. A repeated measures study design was used to assess reliability; in addition several longitudinal single subject case-studies are reported, justifying the sensitivity of the test to detect training induced changes. Inter-day reliability of the measures was assessed with repeated measures 48 h apart and the detection of training induced changes was evaluated by tracking athletes over a normal conditioning period which included resistance and sport specific training. Peak force for the isometric mid-thigh pull was 2879±613 N and 1988±412 N for the squat jump, resulting in a mean Dynamic Strength Deficit of 0.70±0.10. The coefficient of variation ranged from 2.01-3.19 % and intra-class correlation coefficients of 0.952-0.987 were observed. For athletes involved in lower-body maximal strength training, their pre and post measurements recorded changes in isometric mid-thigh pull peak force (215-362 N), and changes in the Dynamic Strength Deficit ratio (0.03-0.14) that exceeded the measures technical error. The Dynamic Strength Deficit ratio, is a reliable means of assessing an athlete's strength qualities, and comparisons of the force measures appear to be a valid means to detect training induced changes in athletes.