Where is the hip joint located?

The hip joint is the articulation between the pelvis and the lower limb. It is a ball-and-socket structure formed by the acetabulum of the pelvis and the femoral head, commonly referred to as the “groin joint.” It serves as the most critical center for lower-limb locomotion in the human body. When the thigh moves, the joint located at the junction of the thigh and buttock is the hip joint.

The hip joint comprises the acetabulum of the pelvis and the femoral head—the proximal end of the femur—united via the joint capsule and surrounding ligaments. As one of the largest and most mobile synovial joints in the body, it permits flexion, extension, adduction, and abduction; thus, its functional role is indispensable. Moreover, due to robust muscular support—including the gluteal muscles and proximal musculature of the femur—the hip joint is also among the most stable large joints in the human body.

The hip joint exists bilaterally (left and right) and constitutes the central pivot linking the trunk to the lower limbs—the key node for force transmission between them. The joint capsule surrounding the hip is exceptionally strong, further reinforced by powerful ligaments. Consequently, hip dislocation is relatively rare under normal physiological conditions; however, under high-energy trauma, complications such as hip dislocation, avascular necrosis of the femoral head, or femoral neck fracture may occur. Therefore, the hip joint is an anatomically and functionally vital joint.