Which muscle is primarily responsible for extending and slightly rotating the hip?

The gluteus maximus is primarily responsible for extending and slightly rotating the hip due to its anatomical positioning and functional capabilities. This muscle is the largest and most superficial of the gluteal muscles, playing a crucial role in movements that involve hip extension, such as standing up from a seated position, climbing stairs, or performing squats.

During hip extension, the gluteus maximus helps to pull the thigh backward, an essential function in both dynamic movements like sprinting and maintaining stability when standing. Additionally, the gluteus maximus assists in external rotation of the hip, especially when the hip is flexed. This dual function contributes to its importance in various athletic and daily activities.

Other muscles mentioned do not serve this primary function. The vastus group, while integral in knee extension, does not significantly affect hip movement. The rectus femoris, part of the quadriceps, is also more focused on knee extension and hip flexion rather than extension and rotation. The pectoralis minor is primarily involved in movements of the shoulder girdle and has no role in hip actions. Thus, the gluteus maximus stands out as the muscle responsible for hip extension and slight rotation.