The hip is a ball and socket joint, which plays an important role in facilitating movements such as walking, jumping and running. It has the greatest range of motion compared to any other joint in the body except for the shoulder. (All joints have a certain range of motion, which is measured in degrees). The hip joint also bears the weight of the body and the force of the leg and hip muscles.
The hip joint is formed where the femur meets the three bones constituting the pelvis: ilium, ischium and the pubis. The femoral head fits into the acetabulum, which is a round socket on the side of the pelvis. It then connects to the femur by the femoral neck, which is essentially just a short section of bone.
The femoral head and acetabulum are coated with smooth cartilage, which is kept slippery by synovial fluid from the synovial membrane. This cartilage enables the bones of the hip to move against each other smoothly without any pain or discomfort. This synovial fluid keeping the cartilage slippery enables the great flexibility, and range of motion of the hip joint.
The hip joint also has ligaments to ensure stability. Ligaments are connective tissue, which connects two bones or cartilage. The ligaments of the hip joint comprise intracapsular ligaments and extracapsular ligaments. The extracapsular ligaments prevent the hip from performing too excessive an abduction and extension of the femur at the hip joint.
The hip joint is also surrounded by muscles. For instance, one may have heard of the gluteal muscles which are the buttock muscles at the back of the hip. The hamstring muscles are also commonly known. They start from the bottom of the pelvis and cross to the back of the hip joint helping to extend the hip.
Hip pain can originate from any of these sources. The hip joint anatomy outlined here is aimed at providing an overview of the basics of hip anatomy. Knowing the basics of hip anatomy may enable a patient or a caregiver to have a more meaningful conversation with their doctor regarding their condition.
The hip is a complicated mechanism and therefore hip pain can originate in many different parts of the joint. Learning the anatomy of your hip will better enable you to pinpoint your pain and work with your doctor to keep it from limiting your life.