Assessment Of Lower Limb Isokinetic Strength At Varying Angular Velocities In Recreationally Active Individuals

INTRODUCTION: The use of isokinetic testing in sport and exercise science is widely used and allows researchers to assess power output and peak torque in the upper and lower extremities. The hamstring to quadricep ratio (H/Q) describes the maximal strength of the hamstring muscles relative to the maximal strength of the quadricep muscles and helps researchers identify imbalances between the muscle groups. PURPOSE: The purpose of this study was to investigate the H/Q ratio at a variety of angular velocities in recreationally active individuals. METHODS: 30 recreationally active individuals (21.4 ± 1.7 yrs) participated in this study. Participants performed three maximal voluntary contractions on an isokinetic dynamometer at angular velocities of 30°/s, 60°/s, 90°/s, 120°/s, 180°/s, 270°/s and 300°/s concentrically in the dominant limb at a comfortable range of motion. The angular velocities were randomized for each participant. A one-way repeated measures ANOVA was conducted to examine differences in the H/Q ratio in the dominant leg. RESULTS: A significant main effect was observed for speed of contraction (p < 0.001). Pairwise comparisons showed significant differences for 30°/s v. 180°/s, 270°/s and 300°/s (p < 0.001); 60°/s v. 180°/s, 270°/s and 300°/s (p < 0.001); 90°/s v. 180°/s, 270°/s and 300°/s (p < 0.05); 120°/s v. 180°/s, 270°/s, and 300°/s (p < 0.001) (Figure 1). CONCLUSION: Angular velocity does significantly impact the H/Q ratio in recreationally active individuals with increases observed at higher angular speeds. These findings may help exercise scientists establish normative values for the H/Q ratio in recreationally active individuals and prescribe effective exercise interventions to minimize lower limb injuries from sport.