Exercise for Building Hip Adductor Strength and Preventing Injury Hip Adduction with Internal Rotation (Stability ball) The hip adductors are the muscles in your inner thigh that support balance and alignment. To improve athletic performance and prevent injury, it’s important that you tone, strengthen, and stretch your hip muscles, including your hip adductors. Instructions: Stand with legs apart, put the stability ball between the legs. Press the ball inward from both sides and release. Anatomi