Does greater hamstrings-to-quadriceps ratio influence countermovement and drop jump performance among females?

Females are more prone to knee injuries, specifically during high velocity movements and dynamic tasks, potentially due to a poorer hamstrings-to-quadriceps ratio (HTQ). This study compared the differences in countermovement jump (CMJ) and drop jump (DJ) performance between females with above average versus below average HTQ.

Twenty-seven females (age = 21.30 ± 2.35 years, height = 165.71 ± 7.17 cm, weight = 65.86 ± 11.39 kg) participated. Peak torque (PT) 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 for all muscle actions. CMJs and DJs were performed on force plates. Subjects were separated into above and below average HTQ groups for each leg and velocity. Independent samples t tests assessed differences in CMJ and DJ performance for above versus below average HTQ groups for each leg independently.

When split by HTQ at MVIC for the right leg, the above average group had a greater CMJ braking phase duration (p = 0.029), while when split by HTQ at 300°⋅s⁻¹, the below average group had a greater braking rate of force development (p = 0.031). When split by HTQ at 300°⋅s⁻¹ for the left leg, the CMJ braking phase duration was greater for the above average group (p = 0.045). There were no differences for DJ metrics (p ≥ 0.069).

Differences were primarily found in the CMJ eccentric phase, which might suggest HTQ has a greater influence on eccentric capabilities. HTQ may provide some relevance regarding eccentric performance in the CMJ, but may offer limited information regarding overall jumping performance.