External rotation — best isokinetic movement pattern for evaluation of muscle function in rotator tendinosis. A prospective study with a 2-year follow-up
Affiliations: [a] Biomechanics Lab, National Hospital, Orthopaedic Center, University of Oslo, Trondheimsveien 132, 0570 Oslo, Norway | [b] Department of Physical Medicine and Rehabilitation, Ullevaal University Hospital, Oslo, Norway
Note: [**] A paper presented at the Fourth International Isokinetic Work-shop, Washington DC, June 1995, in association with the International Society of Clinical Isokinetics.
Abstract: We prospectively performed isokinetic shoulder testing in 31 patients with rotator tendinosis (Impingement, stage II), to evaluate which movement patterns these patients are able to fulfill both before and after treatment. The movement patterns used were external/internal rotation and flexion/extension. The angular velocities were 60°/s and 180°/s and the patients were tested pre-treatment and after 6 and 24 months. Twenty-five of the patients (81%) managed all three external/internal rotation tests. In flexion/extension, however, only eight patients (26%) fulfilled all tests because of pain. Pre-treatment there was an average significant reduction of 25% (P < 0.001) in external rotation, while internal rotation only had a slight reduction of 10%. At 24 months both movement patterns had regained normal strength. Most patients fulfilled the external/internal rotation tests and the performance was weakly correlated to pain compared to the flexion/extension pattern. This suggests that external/internal rotation is the preferrable movement pattern for evaluation of muscle strength deficits per se in patients with rotator tendinosis.
