The hip joint is a ball-and-socket synovial joint designed for a wide range of motion. Articular cartilage lines the femoral head and acetabulum, providing a smooth, low-friction surface. Over time, this cartilage can thin at a rate of roughly 0.1 to 0.2 millimeters per year, particularly after age 40, gradually reducing the joint's ability to absorb shock and distribute load evenly.
As cartilage deteriorates, the underlying bone and surrounding soft tissues compensate by absorbing greater mechanical forces. This increased stress triggers inflammation, which leads to the stiffness, swelling, and pain patients commonly experience. Physical therapy strengthens the muscles surrounding the hip joint, helping distribute load more evenly and reduce pain.
The hip also depends on a network of stabilizing muscles including the gluteus medius, piriformis, and iliopsoas. When these muscles weaken or develop trigger points from prolonged sitting or repetitive strain, they can refer pain deep into the hip joint, creating a cycle of dysfunction that worsens without intervention.
