[Muscle incoordination phenomena after surgical management of proximal rupture of the biceps tendon].

A significant atrophy of the biceps brachii muscle without decreasing maximal force during flexion in the elbow joint was shown at least 1.5 years after surgical refixation in 6 patients with a tendon-rupture of the long head of the right biceps. A decreased myoelectrical activity was found in the caput longum region of the muscle. The decrease correlates with an increase of spectral myoelectrical power in the region of caput breve or brachioradialis muscle. In addition compensatory recruitment processes can be supposed because of changed spectral myoelectrical power in the low-frequency bands. Changes of the morphological structure of the muscle were only found in 1 patient by sonography.