Tennis elbow is technically known as lateral epicondylitis. It is characterised by pain and inflammation around the lateral condyle, the bony lump on the outermost side of the elbow. This is the point at which the major tendons connect to the muscles of the forearm. Although the pain is felt at the site of tissue damage, tennis elbow results from forceful wrist movements.

What causes tennis elbow?

Obviously, playing tennis or other racquet sports is one cause, especially when it occurs in someone who has just taken up tennis or has returned to the sport in later life. Surprisingly perhaps, 95% of cases of tennis elbow are not due to playing tennis at all.

Common activities that can also bring on tennis elbow include gardening, sports that involve throwing, and anything involving repetitive or strenuous use of the forearm muscles. Bricklayers, painters/decorators, butchers, plumbers and carpenters are all vulnerable. Tennis elbow can be caused by a single forceful event, but it usually develops after long-term repetitive strain. 

The main muscle involved in the development of tennis elbow is the extensor carpi radialis brevis (ECRB). When your arm and elbow are straight, the ECRB stabilises your wrist. When the ECRB is overused, small tears can form in the tendon at the point where it connects to the lateral epicondyle. These tears lead to tendonitis, which causes the pain typical of tennis elbow.

Diagnosing tennis elbow

Most people are able to diagnose themselves, modify their activity pattern, take painkillers and manage the problem without needing to seek medical attention.

If you develop pain in the outer elbow, especially when exercising the forearm or wrist and go along to see your GP, he or she will usually diagnose tennis elbow immediately, especially if you have a history of repetitive activity of the forearm.

During your examination, your GP will often use a variety of tests to confirm that the pain is due to tennis elbow and nothing more serious:

  • The best way of investigating the elbow is to straighten your arm in front of you and then pull up your wrist and hand as it you were making a stop sign. If this causes pain, it is likely you have tennis elbow.
  • Tests may need to be done to rule out underlying arthritis, a herniated disc in the spine or a bone fracture. X-rays may be taken to rule out arthritis of the elbow, for example.
  • Your GP may want to investigate potential complications such as nerve damage. This is usually done using an MRI scan. Electromyography (EMG) can be done to rule out nerve compression. Many nerves travel around the elbow and the symptoms of nerve compression are similar to those of tennis elbow.