The hip region is the portion of the human body lateral to the gluteal region that joins the lower extremities to the trunk of the body. The complex collaboration of the muscles, bones and ligaments in the hips and specifically the hip joint are responsible for the bodies’ vast range of motion. The largest components of the hip, the muscles and bones, are designed to support the weight of the human body and aid mobility and balance. Therefore, the bones comprising the hip joint are heavier and stronger and the muscles are bigger and more powerful than any other joint in the human body. As a result, complications or diseases of the hip are especially debilitating to those they affect.
In order to understand ailments of the hip it is important to understand the anatomy of the hip.
The major bones of the hip are the femur and the pelvis. The femur and the pelvis are a joined at the hip joint.
Femur: The femur, also referred to as the thigh bone, is the largest and strongest bone in the human body.
Pelvis: The pelvis, also referred to as the pelvic region, connects the lower part of the trunk to the abdomen and lower extremities.
The hip joint is a ball and socket joint, similar to the shoulder, in which the round ball, or femoral head, of the thigh bone fits into the rounded socket, or acetabulum, of the pelvis. The rounded nature of the femoral head allows it to glide in many planes of direction, enabling you to walk, sit, stand and perform daily functions. The femoral head and the acetabulum come together at the joint capsule where they are covered by the articular cartilage and kept lubricated by the synovial membrane.
In the hip, the major components of the joint capsule are the ligaments, articular cartilage and synovial membrane.
Articular cartilage is a soft, slippery tissue that covers the ends of bones at any joint in the human body. It provides a cushion for bones so they don’t grind together.
Synovial membrane covers the articular cartilage and secretes synovia fluid, the substance responsible for the lubrication of the joints.
Ligaments of the hip are the soft durable tissue that connects the femur to the pelvis. There are several important ligaments in the hip. These ligaments provide the stability to the bones that aids the human body with one of its most essential functions, balance.
The hip muscles are the strongest and most powerful muscles in the body. They support your trunk or core and enable mobility. There are 7 major muscles in the hip, separated into 4 categories the:
- Adductor Group: The adductor group moves your inner leg toward the center line of your body. The adductor group is composed of the adductor magnus, adductor longus & brevis, pectineus, and the gracilis.
- Gluteal Group: The gluteal group also known as the posterior thigh muscles or buttocks, consists of the gluteus maximus, the strongest muscle in the body. This group helps you walk, run, climb or move from a sitting to standing position. The gluteal group consists of the gluteus minimus, gluteus medius, gluteus maximus, and the tensor fasciae latae.
- Iliopsoas Group: The iliopsoas group are the flexor muscles of the hip joint. This group helps you sit up from a lying-down position. The iliopsoas group consists of the psoas major and iliacus.
- Abductor Group: The abductor group aids movement of your leg away from the center line of your body. The abductor group consists of the piriformis muscle and the inferior and superior gemellis muscles.
Range of Motion
If you’re experiencing pain in your hip there is a good possibility you are unable to use your full range of motion. In order to create a comprehensive treatment plan with your doctor it is important to understand the standard for hip mobility.
|Hip Flexion||Bending||0-125 degrees|
|Hip extension||Straightening||115-0 degrees|
|Hip hyperextension||Straightening beyond normal range||0-15 degrees|
|Hip abduction||Move away from central axis of body||0-45 degrees|
|Hip adduction||Moves towards central axis of body||45-0 degrees|
|Hip lateral rotation||Rotation away from the center of the body||0-45 degrees|
|Hip medial rotation||Rotation towards center of body||0-45 degrees|