Comparisons of muscle strength and power in females with above and below average hamstrings-to-quadriceps ratio across the velocity spectrum.

Abstract

Females with above average hamstrings-to-quadriceps ratio (HTQ) will have superior peak torque (PT), mean power (MP), and HTQ compared to those with below average HTQ. 27 college-aged females participated. PT and MP was taken from maximal voluntary isometric contractions (MVICs) and isokinetic knee extensions and flexions performed at 60-300°·s^-1 for each leg. HTQ was the ratio of PT from knee flexion and extension. Subjects were separated into above and below average HTQ groups for each leg and velocity. ANOVAs examined differences in HTQ, PT, and MP across groups and velocities. The above average group had greater HTQ across velocity (p ≤ 0.002) but both groups had the same response where HTQ was the same from MVIC-60°·s^-1, increased from 60 to 120°·s^-1, and plateaued 120-300°·s^-1. Knee extension PT was greater for the below average group (p < 0.030). For both groups, PT decreased across velocity (p ≤ 0.005). Knee flexion PT was highest at MVIC followed by a decrease from 60 to 300°·s^-1 for all groups (p < 0.001). For both groups, PT decreased across velocity (p < 0.005). Knee extension MP was greater for the below average group (p < 0.001). For both groups, MP increased from 60 to 180°·s^-1 (p < 0.001) and plateaued from 180 to 300°·s^-1 (p = 1.000). Knee flexion MP was greater for the above average group (p ≤ 0.013). For both groups, MP increased from 60 to 120°·s^-1 (p < 0.001), plateaued from120 to 240°·s^-1 (p = 1.000), decreased from 240 to 300°·s^-1 (p > 0.426). Above or below HTQ has minimal impact on torque and power production as velocity increases, and should be used with other metrics for injury risk.