Chronic Lateral Epicondylitis. A Randomized Controlled Clinical Trial of Two Physical Training Concepts With Special Reference to Etiology and Treatment Effect

Chronic lateral epicondylitis is defined as the presence of a "tennis elbow" for more than 3 months. It is a common condition in the general population and often results in long-term sick-leave. The etiology is unknown. A large number of treatments have been tried but none is generally accepted. However, in Achilles tendinitis a new treatment has been shown effective. It consists of eccentric exercise, i.e. work during stretching rather than shortening of the muscle (concentric exercise). The latter is currently the most common treatment method.

This project is a randomised controlled clinical trial of eccentric versus concentric exercise in 205 patients with chronic lateral epicondylitis. Pain and muscle strength were recorded at start of treatment and after 1,2,3,6 and 12 months. Activities of daily life (ADL) and well-being were recorded at start of treatment and after 3, 6 and 12 months. In addition, blood specimens for a number of neural peptides have been sampled. Moreover, the involvement of the peripheral nervous system in the elbow area has been examined in a subsample of patients. A biopsy from 20 patients per treatment group and from 20 healthy subjects, and a positron emission tomography (PET) scan of 23 patients were performed to allow qualitative and quantitative examination of neural fibres, peptides and receptors. The health economy of the two treatments will be investigated using data from this project and from available registers.