Which muscle is primarily responsible for hip extension?

The gluteus maximus is primarily responsible for hip extension due to its anatomical position and muscle fiber orientation. This large muscle is located in the posterior aspect of the hip and runs from the ilium, sacrum, and coccyx to the femur. When the gluteus maximus contracts, it pulls the thigh back relative to the trunk, which is the fundamental motion of hip extension.

In addition to its role in hip extension, the gluteus maximus also assists with lateral rotation and abduction of the hip, especially when the leg is raised to the side. Its structure and function make it the most powerful extensor of the hip joint, which is crucial in activities like running, jumping, and climbing.

Other muscles involved in hip movement, like the gluteus minimus, tensor fasciae latae, and psoas major, have different primary functions and are not as effective for hip extension. The gluteus minimus primarily aids in hip abduction and internal rotation, the tensor fasciae latae assists in hip flexion and abduction, and the psoas major is mainly a hip flexor. Therefore, the gluteus maximus stands out as the key muscle for generating hip extension