The Relationship between Isokinetic Open and Closed Chain Lower Extremity Strength and Functional Performance

Abstract

Objectives: To determine (1) correlations between isokinetic lower extremity 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 strength, power, and agility tests was performed at a hospital-based outpatient physical therapy clinic.Participants: A volunteer sample of 29 male and 31 female, college-age subjects participated.Measurements: All subjects were tested in the following isokinetic tests: reciprocal leg press, single-leg squat, and knee extension. Performance tests included single-leg hop and vertical jump and a speed/agility test.Results: Analysis showed isokinetic knee extension, leg press, and single-leg squat strength significantly correlated to all functional tests. There were significant correlations among the 3 different isokinetic strength measures, as well.Conclusions: These results suggest a significant relationship between lower extremity open and closed chain isokinetic strength and functional performance testing.