The relationship between isokinetic open and closed chain lower extremity strength and functional performance

Objectives: To determine (1) correlations between isokinetic lower extremit y strength and functional performance and (2) correlations among different modes of isokinetic testing. Design and Setting: A correlational design with 6 measures. A series of str ength, power, and agility tests was performed at a hospital-based outpatien t physical therapy clinic. Participants: A volunteer sample of 29 male and 31 female, college-age subj ects participated. Measurements: All subjects were tested in the following isokinetic tests: r eciprocal leg press, single-leg squat, and knee extension. Performance test s included single-leg hop and vertical jump and a speed/agility test. Results: Analysis showed isokinetic knee extension, leg press, and single-l eg squat strength significantly correlated to all functional tests. There w ere significant correlations among the 3 different isokinetic strength meas ures, as well. Conclusions: These results suggest a significant relationship between lower extremity open and closed chain isokinetic strength and functional perform ance testing.