The shoulder joint is a ball and socket joint formed by the articulation of the head of the humerus with the glenoid fossa of the scapula (shoulder blade). The shoulder joint is the most mobile joint in the body, which allows us to position the hand anywhere in space. The shoulder joint (gleno-humeral joint) works in close coordination with three other joints in shoulder joint complex : 1. The acromioclavicular (AC) joint - where the clavicle meets the acromion of the scapula; 2. The sternoclavicular (SC) joint - where the clavicle meets the chest bone (sternum); 3. The scapulothoracic joint (where the scapula meets with the ribs at the back of the chest).
The shoulder joint complex connects the upper limb to the trunk. The wide range of motion also makes the joint unstable. The inherent instability is compensated by the rotator cuff muscles, tendons, ligaments, and the glenoid labrum. Any of these structures can be damaged either through injury, overuse or wear and tear.
Shoulder pain is common and is the third most common cause of musculoskeletal consultation in primary care.
Shoulder pain can be caused by:
- Poor posture
- Rotator cuff disorders (most common) – the rotator cuff is a group of muscles and tendons that surround the shoulder joint and help to keep it stable. These muscles have to work with every arm activity we do day to day. Sometimes, due to overuse, a change in activity or just normal age related changes these muscles don’t do their job as well which can result in pain.
- Frozen shoulder – a painful condition that reduces normal movement in the joint and can sometimes prevent movement in the shoulder altogether
- Shoulder instability – where the shoulder is unstable and may have an unusually large range of movement (hypermobility)
- Acromioclavicular joint disorders – conditions, including osteoarthritis that affect the acromioclavicular joint, which is the joint at the top of the shoulder
- Osteoarthritis in the shoulder joints
- A broken (fractured) bone, such as a fracture of the humerus (upper arm bone) or clavicle (collarbone) or Scapula (shoulder blade)
- In some cases, pain in the shoulder could be caused by a problem in another area, such as the neck, that is felt in the shoulder and upper back. Besides heart problems could present with shoulder pain.
The good news is that if you have shoulder pain that has come on gradually or without any history of trauma then simple exercises that help these muscles work better can help get your pain better.
Symptoms of shoulder pain
Pain around the front and/or side of the shoulder and in some cases radiation to arm and forearm. Pain is made worse by movement, e.g. raising arm above shoulder level or the action of putting on a coat. Some people will complain of pain at night, particularly when lying on the affected side.
Diagnosing Shoulder Pain
There are many causes of shoulder pain but generally, as long as you haven’t had a history of a fall or injury most shoulder pain responds well to exercises that make the rotator cuff muscles stronger. Half of all first time episodes of shoulder pain get better without treatment in 6 to 12 weeks.
X-rays and other investigations are not usually necessary during the first episode of pain. They are only indicated if you fail to respond to the advice and exercises recommended below.
Common Shoulder conditions
- Rotator cuff tendinopathy
- Subacromial/subdeltoid bursitis
- Impingement syndrome
- Rotator cuff tear
- Acromio clavicular joint arthritis
- Adhesive capsulitis
- Clavicle fractures
- Proximal humerus fractures
- Gleno humeral dislocation
- Acromioclavicular joint sprain or dislocation (shoulder separation)