Shoulder pain: Causes, diagnosis, treatment
The shoulder is one of the largest and most complex joints in the body.
The shoulder joint is formed where the humerus (upper arm bone) fits into the scapula (shoulder blade), like a ball and socket. Other important bones in the shoulder include:
- The acromion, or acromion process, is a bony projection off the scapula.
- The clavicle (collarbone) meets the acromion in the acromioclavicular joint.
- The coracoid process is a hook-like bony projection from the scapula.
The shoulder has several other important structures:
- The rotator cuff is a collection of muscles and tendons that surround the shoulder, giving it support and allowing a wide range of motion.
- The bursa is a small sac of fluid that cushions and protects the tendons of the rotator cuff.
- A cuff of cartilage called the labrum forms a cup for the ball-like head of the humerus to fit into.
The humerus fits relatively loosely into the shoulder joint. This gives the shoulder a wide range of motion, but also makes it vulnerable to injury.
Shoulder pain is quite common, affecting around three in 10 adults at some time during their lives.
What causes shoulder pain?
The shoulder is a ball and socket joint with a large range of movement. Such a mobile joint tends to be more susceptible to injury. Shoulder pain can stem from one or more of the following causes:
- Strains from overexertion
- Tendonitis from overuse
- Shoulder joint instability
- Collar or upper-arm bone fractures
- Frozen shoulder
- Pinched nerves (also called radiculopathy)
How is shoulder pain diagnosed?
The first step in diagnosis is for a doctor to ask you questions about your shoulder pain. He will probably also carry out a physical examination looking for differences between the shoulders, redness, swelling bruising and signs of dislocation.
The shoulder joint may be moved to see if any particular movement causes pain.
Depending on this initial diagnosis, further tests may be required, including:
- X-rays. Plain X-rays can reveal narrowing of the space between the two shoulder joint bones, damage to the bones and signs of arthritis.
- MRI. Magnetic resonance imaging is a non-invasive procedure that can reveal the detail of the shoulder joint.
- Blood tests: A doctor may wish to rule out inflammatory conditions such as polymyalgia rheumatica (PMR).
Who is at risk of shoulder pain?
People at risk of getting shoulder pain range from those who play contact sport like rugby, to those with condition such as diabetes and overactive thyroid.
Suffering a traumatic incident, such as a car accident may also result in shoulder pain.
How is shoulder pain treated?
The treatment of soft-tissue shoulder pain includes the use of anti-inflammatory medication and/or paracetamol. Pain may also be treated with a local application of moist heat or ice.
A local corticosteroid injection is often helpful for inflammation of the shoulder. For shoulder pain, movement exercises and physiotherapy may help. For cases in which tendons or ligaments are involved, surgical procedures may be necessary.