Relationship of Knee Extensor Strength and Hopping Test Performance in the Assessment of Lower Extremity Function (original) (raw)
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Journal of Sport Rehabilitation, 2001
Isokinetic strength and functional performance are used to assess recovery after rehabilitation. It is not known whether low-speed closed-linear-kinetic isokinetic muscle strength correlates with functional performance. Objective: To investigate the relationship between linear closed (CKC) and open (OKC) concentric isokinetic strength of the dominant lower-limb extensors and functional performance. Design: Correlational analysis. Setting: University laboratory. Participants: Thirty uninjured men and women (age = 20.9 ± 2.4 years). Main Outcome Measures: Peak CKC and OKC isokinetic strength and best score from a shuttle run for time, single-leg vertical jump, and single-leg hop for distance. Results: Neither lower-limb CKC nor OKC isokinetic strength measured at low speeds correlated highly with performance on the functional tasks of jumping, hopping, and speed/agility. Conclusions: Although the basis of both closed and open isokinetic strength must be appreciated, they should not be the only determinants of functional performance.
Journal of Physical Therapy Science, 2018
The main purpose of the study was to examine the relationship of a battery of frequently used functional assessment tests with quadriceps and hamstrings isokinetic strength in Knee-osteoarthritis (OA) patients. Secondarily, the predictability of isokinetic strength on these performance variables was also assessed. [Subjects and Methods] Seventeen males and 23 females with Knee-OA, were assessed via a) the common functional tests: 6-minute walk test, Timed up-and-go test, 30-second chair test and 12-stair test and b) isokinetic concentric extension-flexion at 120°/s and 180°/s. [Results] Both Knee Extension and Flexion Peak Torque per Body weight showed moderate to strong, statistically significant correlation, with all 4-functional performance tests, for both velocities. Both 12-stair test and 30-second chair test were significant predictors in all analyses, while the 6-minute walk test was an additional significant predictor of the 120°/s knee flexion. [Conclusion] Thigh muscle strength in both tested velocities proved to be significantly correlated with functional performance. The 12-stair test and 30-second chair test results were significant predictors for isokinetic extension and flexion in both velocities. It appears that those two tests challenge the knee and the surrounding musculature in a manner that reflects muscle strength.
The effects of knee extensor eccentric training on functional tests in healthy subjects
Brazilian Journal of Physical Therapy, 2010
Background: It is well known that eccentric training increases muscle strength and promotes greater neural activation, and therefore has been used in the recovery of knee extensors. The hypothesis of this study was that there would be a strong correlation between knee extensor torque and functional tests. Objectives: To investigate the relationship between knee extensor peak torque and functional tests of agility (runs) and propulsion (hop for distance) after short-term isokinetic eccentric training. Methods: Twenty healthy and active male undergraduate students (age 22.5±2.1 years; height 1.72±0.10 m; weight 67.8±9.5 kg; body mass index: 22.5±2.0 kg/m 2 ), with no abnormalities or history of injury of the limbs, performed an isokinetic assessment of the knee extensors and flexors and also functional tests before and after isokinetic training, which consisted of 3 sets of 10 MVECs at 30 o /s, with 3 minutes of rest between sets, twice a week for 6 weeks. Results: The eccentric training increased the extensor peak torque (16, 27 and 17%; P<0.01) and decreased the H/Q ratio (10, 20 and 13%; P<0.01) for the isometric and eccentric modes at 30°/s and 120°/s, respectively. It also decreased the time in two of the five agility tests (carioca and pivot diagonal; P<0.01), and increased the distance in the hop tests, for both dominant and non-dominant limbs (P<0.01). Conclusions: Although the eccentric training led to an increase in extensor peak torques as well as an improvement in most of the functional tests, the hypothesis that a strong correlation would be observed between peak torques and functional tests was not confirmed. Article registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) under the number 12607000590460. Resumo Contextualização: Sabe-se que o treino excêntrico aumenta a força muscular, promovendo uma maior ativação neural e, portanto, tem sido usado na recuperação do torque extensor. A hipótese deste estudo foi a de que possa existir uma forte correlação entre o torque extensor do joelho e os testes funcionais. Objetivos: Correlacionar o torque extensor do joelho com os testes funcionais de agilidade (corridas) e impulsão (saltos em distância) após o treino isocinético excêntrico de curta duração. Métodos: Vinte homens universitários, ativos e saudáveis (22,5±2,1 anos; 1,72±0,10 m; 67,8±9,5 kg; IMC 22,5±2,0 kg/m 2 ), sem reportar anormalidades ou história de lesão no membro inferior, realizaram avaliação isocinética do torque extensor e flexor do joelho e testes funcionais antes e depois do treino isocinético que consistiu em três séries de 10 CEVM a 30º/s, com 3 minutos de repouso entre as séries, realizado duas vezes por semana, durante seis semanas. Resultados: O torque extensor aumentou (16, 27 e 17%; P<0,01), a razão I/Q diminuiu (10, 20 e 13%; p<0,01) para os modos: isométrico e excêntrico a 30°/s e 120°/s, respectivamente; diminuiu o tempo em dois dos cinco testes de corridas (carioca e pivô diagonal; P<0,01) e aumentou a distância nos testes de saltos tanto para o membro dominante quanto para o não dominante (P<0,01). Conclusões: Embora o treino excêntrico tenha aumentado o torque dos extensores do joelho, bem como melhorado a maioria dos testes funcionais, a hipótese de uma forte correlação entre essas variáveis não se confirmou. Artigo registrado no Australian New Zealand Clinical Trials Registry (ANZCTR) sob o número 12607000590460.
Ability of closed and open kinetic chain tests of muscular strength to assess functional performance
Scandinavian Journal of Medicine and Science in Sports, 2000
The purpose of this study was to investigate the ability of closed and open kinetic chain tests of muscular strength to assess functional performance. Sixteen healthy male subjects, with a mean (∫SD) age, body mass and height of 27∫5 years, 78∫9 kg and 183∫9 cm, respectively, volunteered to participate in the study. In the closed kinetic chain test (involving muscles working across multiple joints), the subjects performed a 3 repetition maximum (3 RM) barbell squat. The open kinetic chain test (involving muscles working across a single joint) consisted of a concentric isokinetic knee extension at an angular velocity of 60ae/s, and was performed using a Kinetic Communicator II
Reliability of an Isokinetic Test of Muscle Strength and Endurance
Journal of Orthopaedic & Sports Physical Therapy, 1989
The reliability of an isokinetic test of muscle strength and endurance was evaluated. Eleven males and 9 females underwent testing on three separate occasions, 2-4 days apart. The protocol included a velocity spectrum test (VST-5 repetitions at velocities ranging from 90-330°/sec) and a muscle endurance test (number of contractions performed in 45 sec at 180°/sec). In the VST, no significant within-subject test day differences were noted at any velocity. Reliability was generally higher at slower velocities and higher for knee extension than flexion. Mean intraclass correlation coefficients (ICCs) for peak torque across velocities were 0.88 for extension and 0.79 for flexion. For the endurance test, two reliable measures were total work performed and average power (ICCs = 0.92); relative endurance measures had ICCs of less than 0.80. Thresholds for demonstrating experimental effects and the number of subjects to test at different detection levels are-recommended.
Reliability of an Isokinetic Test of Muscle Strength and Endurance 1
Journal of Orthopaedic & Sports Physical Therapy, 1989
The reliability of an isokinetic test of muscle strength and endurance was evaluated. Eleven males and 9 females underwent testing on three separate occasions, 2-4 days apart. The protocol included a velocity spectrum test (VST-5 repetitions at velocities ranging from 90-330°/sec) and a muscle endurance test (number of contractions performed in 45 sec at 180°/sec). In the VST, no significant within-subject test day differences were noted at any velocity. Reliability was generally higher at slower velocities and higher for knee extension than flexion. Mean intraclass correlation coefficients (ICCs) for peak torque across velocities were 0.88 for extension and 0.79 for flexion. For the endurance test, two reliable measures were total work performed and average power (ICCs = 0.92); relative endurance measures had ICCs of less than 0.80. Thresholds for demonstrating experimental effects and the number of subjects to test at different detection levels are-recommended.
An Adequate Interset Rest Period for Strength Recovery During a Common Isokinetic Test
Journal of Strength and Conditioning Research, 2013
Isokinetic testing is used in rehabilitation settings on a regular basis; yet, there is a lack of consistency in rest period usage among protocols. Furthermore, the allotment of rest periods has been arbitrary (e.g., 30, 60, 90 seconds or more). This investigation examines the work:rest ratio as an effective method of standardizing rest periods in isokinetic testing. The purpose of this study was to establish an adequate rest period that would allow reproducibility of strength during a common isokinetic strength test. Twenty-seven healthy college-aged men (age, 23 6 3.8 years; body weight, 79.54 6 11.09 kg) were tested on 5 separate occasions: 2 familiarization sessions and 3 experimental sessions. Each subject performed a knee extension/flexion isokinetic strength protocol (Cybex NORM; Lumex, Inc., Ronkonkoma, NY, USA) to determine peak torque by performing 5 maximal reciprocal repetitions at each ascending velocity of 60, 180, and 3008$s 21. Work:rest ratios of 1:3, 1:8, and 1:12 were counterbalanced between sets. A 3 3 3 repeated measures analysis of variance was used to analyze the data. A significance level of a # 0.05 was used for all tests. There was no significant difference in either knee extension or knee flexion peak torque when comparing work:rest ratios. These findings suggest that a 1:3 work:rest ratio is sufficient during a common isokinetic strength test.
Influence of recovery time on strength during a testing protocol of knee
Journal de Traumatologie du Sport, 2016
The aim of the present study was to compare the influence of three rest intervals of 30, 60 and 180 seconds randomly applied between two sets of five isokinetic contractions of flexor-extensor knee muscles in a cohort composed of 14 men (32.5 ± 8 years). The comparison of the isokinetic values measured during the first set of each evaluation session showed no significant differences (0.55 < P < 0.80). The analysis of the time and rest interval interaction demonstrated no significant difference between the isokinetic measures obtained after the rest intervals for peak torque of the quadriceps and of the hamstrings and for the mean power of the quadriceps and the hamstrings. These findings raise questions about a strict energetic approach and a future research should analyze the interaction of force production and fatigue phenomena in relation to the rest interval.
BACKGROUND: Few studies have assessed the test-retest reliability of the isokinetic strength at 90 • /s and the isometric parameters for knee extensors. OBJECTIVES: To assess the reliability of isokinetic and isometric parameters of knee extensors, and to determine the smallest real difference between the test-retest measures. METHODS: Knee extensor strength was measured twice, 4 to 5 days apart, using a Biodex dynamometer in forty subjects (12 men, 28 women). The protocols consisted of 5 concentric contractions at 90 • /s and 5 isometric contractions. RESULTS: For women, test-retest reliability was very high for isometric and isokinetic peak-torque (ICCc,1 > 0.9 ), moderate for work (ICCc,1 = 0.82) and questionable for angle of peak torque (Angle-PT), mean Angle-PT and rate of torque development (RTD0−100 ms) (ICC < 0.67). The measurement errors were small for all variables, the SEM% ranged between 3.1% to 7.4%, and SRD% from 8.6% to 19.9%, except for RTD0−100 ms that was the most variable (SEM% = 16.4%; SRD = 47.5%). No differences were found in Angle-PT and RTD0−100 ms with regard to sex. CONCLUSIONS: The isokinetic values obtained at 90 • /s and isometric peak-torque for knee extensors are highly repeatable with a standardized test protocol and the SRD values can be used to detect real changes. Alternative strategies of analysis should be developed to improve reliability of Angle-PT and RTD0−100 ms. Angle-PT and RTD0−100 ms do not appear affected by gender