Which muscle does not contribute to hip adduction?

The gluteus medius is the muscle that does not contribute to hip adduction. Its primary function is to abduct the hip, meaning it helps to move the leg away from the body. The gluteus medius is particularly active during activities such as walking or running, where it stabilizes the pelvis and prevents it from tilting during movement.

In contrast, the other muscles listed—adductor longus, gracilis, and adductor magnus—are all part of the adductor group in the inner thigh. These muscles play a significant role in pulling the leg towards the midline of the body, facilitating hip adduction. Therefore, while the gluteus medius is essential for abduction and stabilization, it does not participate in the action of adduction of the hip.