This union supports weight bearing as well as absorbing the forces created by physical activity, standing, and sitting. Strong capsular ligaments surround and support the hip joint, and muscles from the lower back, pelvis and thigh contribute to strength and stability. The head of the femur is covered with a smooth layer of cartilage, which helps to absorb shock and reduce friction during movement, while synovial fluid further cushions the joint and transports essential nutrients to joint structures.
Important differences exist in the size and structure of the hip and pelvis in men and women.
A woman's bone structure is slightly less dense than a man's, and the pelvis is smaller, shorter and wider. Additionally, the bony protrusions for muscle attachment are not as sharply defined. Muscle Strain One of the most common problems of the hip is a muscle strain or tear. This frequently occurs when an athlete tries to change directions, or start and stop suddenly. Frequently there is a sudden onset of pain and swelling.