Hip anatomy – A complicated joint

Last modified: December 11, 2019

The hip, or more specifically the hip joint, is one of the largest joints in the body. It consists of what is known as a ball-and-socket type joint, which means that the head of the joint looks like a ball. This allows the joint to move in all directions, even if the hip is not as mobile as the shoulder joint, for example, which is also a ball-and-socket joint. The hip anatomy also includes the acetabulum, which is located in the pelvis. The ball of the hip joint fits into this. Both joint surfaces are also covered with a layer of cartilage. This articular cartilage allows smooth movements without friction and protects the joints. In addition, the ligaments, joint capsule and muscles hold the hip joint in place. They stabilize the hip joint and enable it to support a large part of the body’s weight.

Load on the hip

The hip joints are among the joints in the lower body that have to work hard. They are the joints that support our entire body weight when we are walking and standing. If the load is too high or if the muscles are exposed to repeated loads for a long period, the muscles can suffer from excess strain. On a microscopic level, the muscles can suffer micro-ruptures which cause pain.

In the short term, the treatment is to allow the muscles to rest and repair, but in the long term it is most important to learn to load the muscles and the area correctly.

If the hips are exposed to high loads as well as incorrect loads, for example from daily, heavy loads in a twisted position, osteoarthritis can develop. Osteoarthritis is a disease that breaks down the cartilage in the joint and can cause both pain and stiffness. There is no cure for osteoarthritis, but with the help of instructor-led and regular training you can reduce the pain.

Continue reading about osteoarthritis.

Pelvis and hip bones

The hips consist of two major skeletal parts: the pelvis and the femur. In turn, the pelvis consists of four different symmetrical parts on the right and left side. These skeletal parts in the pelvis are called the pubis, the ischium, the ilium and the sacrum. These bones are all flat and strong, they connect the upper body to the lower body. The pelvis also protects our internal organs.

The pelvis is held together by strong joints – in the back with the sacroiliac joints and in the front with the pubic symphysis joint. These pelvic joints relax when a woman is pregnant and the body is preparing to deliver a baby.  


The anatomy of the hip is complicated in the form of several muscles, ligaments and a tight joint capsule that hold the joint together. This design means that we can move the joint.

The groin is a structure that is located right next to the hip joint. It is made up of the creases between the thigh and abdomen. The groin is a complex structure in itself which consists of ligaments and muscles.

The groin is relatively sensitive and the muscles here could be strained if a person is not sufficiently warmed up before a training session, for example, which can cause pain. A person with a groin problem may experience some pain relief by stretching the hip flexor muscles. When performing this exercise, it is important to remember that it should pull but not cause pain.

Surgery of the hip

The hip joint is largely responsible for the body’s movement in the lower body. This means that any injury or disease in the hip can have a significant effect on the rest of the body. In particular, movement may be affected. A person who is experiencing pain and/or stiffness in the hip should see a doctor or physiotherapist for an assessment.

In older people, many hip operations take place because the joints may have been severely changed through osteoarthritis and may need to be replaced. If someone has suffered from osteoarthritis for a long time, training has not produced satisfactory results and the pain is seriously restricting daily life, it may be necessary to operate the hip as a last resort. The operation involves replacing the hip joint with a prosthesis of metal and plastic.

Go back to the homepage to read about osteoarthritis.