The shoulder joint offers more motion in more varied directions than any other joint. The shoulder joint is a ball and socket type joint. The ball is the top of the arm bone and the socket is part of the shoulder blade. Enveloping this ball-and-socket joint is a capsule of tissue. Frozen shoulder, or adhesive capsulitis, is a condition that causes restriction of motion in the shoulder joint. Frozen shoulder causes the capsule surrounding the shoulder joint to contract and form scar tissue. The eventual result is that the shoulder bone is restricted from moving in the socket. Also, the soft sacs cushioning the joint called bursas can stick together resulting in a loss of ability to move the shoulder. The shoulder actually becomes frozen, thus the name 'frozen shoulder.'

The cause of a frozen shoulder has not been clearly identified; however it can occur for no apparent reason. For different possible triggers, the shoulder joint becomes scarred and stiff. The pain that comes with frozen shoulder can be extremely intense. Major symptoms of frozen shoulder include loss of motion or pain when lying on the affected side. Other symptoms include issues such as when extending the arm there is sharp pain at the front of the shoulder, pain when reaching for the hip pocket or pain down the external upper side of the arm. Any of these symptoms can have negative life affects such as an inability to drive and immobility that impedes physical work.

Immobility and stiffness is a key symptom used to diagnose frozen shoulder. You are unable to move the arm and if you try it is very painful. The shoulder becomes stuck or stiff for a time which could last from anywhere between forty hours to a month in duration. It can be so painful that people often cannot work. It can have a devastating effect on your life and fitness levels.

Inflammation is another important symptom of frozen shoulder. The Lax Capsular Sack and the Synovial Fluid within the joint will become thick and sticky. It can often take place after physical trauma. If left untreated, inflammation spreads into other shoulder soft-tissues and can cause swelling in other shoulder sacks. The stiffness is a response to the body countering the inflammation, so the brain starts to turn off the muscles. Over time such as a week or more, stiffness reduces movement so much that the shoulder becomes frozen.

Treatment for frozen shoulder can include exercises and stretching in order to increase the motion in the joint and minimize muscle loss. Frozen shoulder can be treated successfully when working with a therapist. Physical therapists create exercise and stretching programs, as well as integrating ice, heat, ultrasound, and other treatments in their therapy sessions. Another treatment is using moist heat to loosen the joint and provide relief of pain. Anti-inflammatory medications can be used to reduce the severity of the pain. Cortisone injections are used to decrease the inflammation in the frozen shoulder joint and this treatment can help to decrease severe pain. Sometimes a patient will require surgery where the surgeon may perform a manipulation while the patient is under anesthesia. Most people who develop a frozen shoulder will recover their functional motion.