A SINGLE SESSION OF HIP ABDUCTORS RESISTANCE EXERCISE UNTIL FAILURE DOES NOT CHANGE DYNAMIC KNEE VALGUS AND MUSCLE ACTIVATION DURING LANDING TASKS

Abstract

The hip abductors play a key role on lower limb alignment with their weakness can lead to misalignment during weight-bearing tasks. Muscle fatigue through physical exercise is a common strategy to cause muscle strength reduction and to be able to investigate the impact on lower limb control. The aim of study was to verify the effect of a single session of hip abductors resistance exercise until failure on the dynamic knee valgus and activation of the hip abductor muscles during single-leg and double-leg landings. Seventeen participants with experience in strength training performed single-leg and double-leg landings with measurements of gluteus medius (GMed) and tensor fascia latae (TFL) muscle activation and frontal plane kinematics (dynamic valgus index) before and after the session of exercise for hip abductors (4 sets of 10 RM with a 2-minute rest between sets). Dynamic valgus index was higher in the single-leg landing compared to double-leg landing (p < 0.001), without effect of fatigue (p = 0.613). GMed and TFL activation were higher in single-leg landing compared to double-leg landing (p<0.001), without effect of fatigue (p > 0.05). A single session of hip abductors resistance exercise until failure did not change dynamic knee valgus and hip abductors muscle activation. Also, the single-leg landing promotes higher dynamic knee valgus and muscle activation of GMed and TFL compared to double-leg landing.