Preseason strength and flexibility imbalances associated with athletic injuries in female collegiate athletes

TLDR

A cohort of 138 female collegiate athletes from eight weight‑bearing varsity sports underwent preseason isokinetic strength testing of knee flexors and extensors at 30 and 180 deg/s, active range‑of‑motion flexibility assessments of lower‑body joints, and were monitored for injuries by an athletic trainer during their seasons. Forty percent of the athletes sustained injuries, and lower‑extremity injury risk was higher when a right knee flexor was 15 % stronger than the left at 180 deg/s, a right hip extensor was 15 % more flexible than the left, or the knee flexor/extensor ratio was below 0.75 at 180 deg/s, demonstrating that specific strength and flexibility imbalances predict injury.

Abstract

One hundred thirty-eight female collegiate athletes, participating in eight weightbearing varsity sports, were administered preseason strength and flexibility tests and followed for injuries during their sports seasons. Strength was measured as the maximal isokinetic torque of the right and left knee flexors and knee extensors at 30 and 180 deg/sec. Flexibility was measured as the active range of motion of several lower body joints. An athletic trainer evaluated and recorded injuries occurring to the athletes in practice or competition. Forty percent of the women suffered one or more injuries. Athletes experienced more lower extremity injuries if they had: 1) a right knee flexor 15% stronger than the left knee flexor at 180 deg/sec; 2) a right hip extensor 15% more flexible than the left hip extensor; 3) a knee flexor/knee extensor ratio of less than 0.75 at 180 deg/sec. There was a trend for higher injury rates to be associated with knee flexor or hip extensor imbalances of 15% or more on either side of the body. These data demonstrate that specific strength and flexibility imbalances are associated with lower extremity injuries in female collegiate athletes.