Which muscle is mainly responsible for hip adduction?

The muscle primarily responsible for hip adduction is the adductor longus. This muscle is located in the inner thigh and plays a crucial role in bringing the legs toward the midline of the body. In terms of anatomy, the adductor longus originates from the pubis and inserts onto the linea aspera of the femur. When it contracts, it pulls the thigh inward, thus facilitating adduction.

While other muscles mentioned also have important roles, their primary functions differ. For instance, the gluteus maximus is primarily involved in hip extension and external rotation, rather than adduction. The pectineus contributes to both hip flexion and adduction, but it is generally not the main muscle associated with adduction specifically. The quadratus femoris primarily functions in external rotation of the thigh and does not have a significant role in adducting the hip. Therefore, the adductor longus stands out as the key muscle responsible for this motion.