OBJECTIVE: To assess the reproducibility of isokinetic eccentric and concentric knee extension and flexion strength indices obtained at two different angular velocities. DESIGN: Cohort study. SETTING: University human performance laboratory. PARTICIPANTS: 45 healthy physically active young adults (25 males). MAIN OUTCOME MEASURES: A non reciprocal protocol of concentric and eccentric contractions of the knee extensors and flexors was performed at 30 and 120°/s. Strength indices evaluated included peak moment; dynamic control ratios; and the difference between eccentric and concentric ratio at the two angular velocities. RESULTS: No evidence for inter-test bias in any of the strength indices was noted. Measurement precision for peak moment, as quantified using ratio limits of agreement, suggest that scores may be expected to vary up to 15% for the knee extensors in both eccentric and concentric contraction modes. An error of up to 19% was calculated for the peak moment scores of the knee flexors. Intraclass correlation coefficients revealed fairly robust preservation of participants' rank order for the majority of strength indices (>0.85). CONCLUSION: Isokinetic-related indices of knee muscles performance enable an acceptable level of detection of expected changes in muscular strength parameters as a result of planned interventions.
OBJECTIVE: To assess the reproducibility of isokinetic eccentric and concentric knee extension and flexion strength indices obtained at two different angular velocities. DESIGN: Cohort study. SETTING: University human performance laboratory. PARTICIPANTS: 45 healthy physically active young adults (25 males). MAIN OUTCOME MEASURES: A non reciprocal protocol of concentric and eccentric contractions of the knee extensors and flexors was performed at 30 and 120°/s. Strength indices evaluated included peak moment; dynamic control ratios; and the difference between eccentric and concentric ratio at the two angular velocities. RESULTS: No evidence for inter-test bias in any of the strength indices was noted. Measurement precision for peak moment, as quantified using ratio limits of agreement, suggest that scores may be expected to vary up to 15% for the knee extensors in both eccentric and concentric contraction modes. An error of up to 19% was calculated for the peak moment scores of the knee flexors. Intraclass correlation coefficients revealed fairly robust preservation of participants' rank order for the majority of strength indices (>0.85). CONCLUSION: Isokinetic-related indices of knee muscles performance enable an acceptable level of detection of expected changes in muscular strength parameters as a result of planned interventions.
Authors: Aldo Scafoglieri; Jona Van den Broeck; Stijn Willems; Rob Tamminga; Henk van der Hoeven; Yde Engelsma; Stijn Haverkamp Journal: BMC Musculoskelet Disord Date: 2021-05-15 Impact factor: 2.362
Authors: Susanne Beischer; Eric Hamrin Senorski; Christoffer Thomeé; Kristian Samuelsson; Roland Thomeé Journal: BMJ Open Sport Exerc Med Date: 2019-02-26
Authors: Thomas Kienbacher; Grace Achim-Gunacker; Melanie Pachner; Katharina Kerschan-Schindl; Patrik Gunacker; Richard Habenicht; Walter Klepetko; Peter Jaksch; Stephan Doblhammer; Gerold Ebenbichler Journal: Am J Phys Med Rehabil Date: 2018-06 Impact factor: 2.159