What best describes a function of the gluteus maximus?

The gluteus maximus is primarily responsible for assisting in hip extension and external rotation. This muscle is one of the largest and strongest in the body, playing a critical role in movements such as standing up from a seated position, climbing stairs, and maintaining an upright posture during activities.

When the thigh is extended backward, particularly during activities like walking, running, or jumping, the gluteus maximus is heavily engaged to provide the necessary power and stability. Additionally, the external rotation of the hip, which involves turning the thigh outward, is another significant function of this muscle. This dual action aids in both mobility and maintaining proper alignment of the lower body during various physical activities.

In contrast, other options describe functions of different muscles or movements not associated with the gluteus maximus. Adduction of the thigh, flexing the hip joint, and stabilizing the knee joint are primarily the responsibilities of other muscles, highlighting the specific role that the gluteus maximus plays in hip movement and stability.