What is Shoulder pain

Shoulder Pain The shoulder is a ball-and-socket joint formed by the head of the humerus (the arm bone) and the glenoid labrum (the name for the socket of the shoulder joint in the scapula). The shoulder joint is very mobile – allowing great freedom of movement for the arm (much more than the equivalent joint in the hip). This greater mobility means that te shoulder joint is less stable. The stability of the shoulder joint also relies a lot on the ‘rotator cuff muscles’ – four muscles (supraspinatus, infraspinatus, subscapularis, teres minor) inserting around the shoulder joint that help move it, as well as providing stability. These muscles are a common source of pain. Shoulder pain is common, and can result from a number of conditions. Importantly, pain felt in the shoulder region does not necessarily mean that the pain is coming from the shoulder. The pain could be caused by neck problems, or referred from internal structures like the lungs, heart, or even the liver or gallbladder.

Statistics on Shoulder pain

Shoulder problems are common, especially in the older population. Rotator cuff problems are believed to be present in as many as 25% of those over the age of 50 – though these are not always symptomatic.

Risk Factors for Shoulder pain

The commonest causes of shoulder pain include:

Progression of Shoulder pain

The natural histories will differ depending on the cause. Importantly, the following clues can be useful in deciding the cause:

  • If the pain is present day and night and is constant – a malignancy (cancer) may be present, especially when associated with weight loss – and this requires urgent assessment.
  • Pain of gradual onset (days) that is worse in the morning or after inactivity is suggestive of inflammation.
  • A preceding injury/trauma may be a causative factor for supraspinatus tendinitis or frozen shoulder.
  • The rapid onset of pain, with fever, with severe restriction of movements is suggestive of septic arthritis.
  • Pain in both shoulders, frequently associated with hip pain may be due to polymyalgia rheumatica.

How is Shoulder pain Diagnosed?

  • ESR – epecially for polymyalgia rheumatica
  • Rheumatoid factor
  • ECG – need to rule out cardiac source of pain
  • Imaging
  • X-ray of glenohumeral and/or AC joint
  • X-ray of cervical spine if suspected
  • CT scan (limited use)

Prognosis of Shoulder pain

The prognosis largely depends on what the cause of shoulder pain is, and when it is diagnosed. Early diagnosis is important in the serious conditions (infections, cancers) to increase the chances of successful treatment and prevention of disability.

How is Shoulder pain Treated?

Treatment depends on the cause. For specific treatment for the following conditions – please see the separate sections:

Shoulder pain References

[1] Kumar P, Clark M. CLINICAL MEDICINE. WB Saunders 2002; [2] Murtagh, J. General Practice. Second Ed. McGraw-Hill, 1998.