Decreased intramuscular blood flow in patients with lateral epicondylitis.

The purpose of this pilot study was to investigate intramuscular microcirculation in extensor carpi radialis brevis (ECRB) in patients with lateral epicondylitis. Ten patients with unilateral epicondylitis, mean duration of symptoms of 39 (12-96) months participated. The diagnosis was based on clinical examination and none was under treatment for the last 6 months. Isometric handgrip strength, 2-pinch grip strength and muscle strength during radial deviation and dorsal extension were determined. Functional perceived pain was evaluated by a modified behaviour rating scale and perceived pain during contraction by visual analogue scale. Intramuscular and skin blood flow was recorded by a laser-Doppler flowmetry system technique (LDF) during stable temperature condition. Intramuscular blood flow was significantly lower in the affected side, 22.7+/-9.8 perfusion units (PU), as compared with 35.2+/-11.9 PU in the control side (P=0.01). There was no difference in skin blood flow or temperature between the affected and the control side. A positive correlation was found between the duration of symptoms and the difference in intramuscular blood flow between the affected and the control arm (r=0.65, P=0.06). The present data indicate that decreased microcirculation and anaerobic metabolism in ECRB may contribute to the lateral epicondylitis symptoms.