This is shown with local tenderness over the common forearm extensor tendon insertion at the lateral epicondyle. This can be extended to the extensor mass, with less annular ligament. Pain can be reproduced with resisted wrist and middle finger extension and with gripping activities. It is possible that symptoms are generated by passive wrist flexion with elbow extension. It is often seen that the flexibility and the strength in the wrist extensor and posterior shoulder muscles are deficient. However, in the workplace where repetitive elbow and wrist motion is involved, lateral epicondylitis occurs. On the lateral epicondyle it’s about 7 times more common than on the medial epicondyle.
In a lot of cases of this specific pathology, the insertion of the extensor carpi radialis brevis is involved. However the extensor carpi radialis longus and anterior extensor communis tendons rarely occur. The description of microscopic failure at the enthesis is a result of repetitive overuse of the extensor forearm muscles. Pathology research has added mucinioid degeneration and granulation tissue in the subtendinous space.
Today, the state of lateral epicondylitis is well known to arise spontaneously or in combination with other recreational and occupational pursuits.
Recently, researchers have advised using the terms “tendinosis” or “tendinopathy” to reflect the chronicity of the condition because a lack of acute inflammatory markers in patients with tennis elbow is indicated.