Abstract
Shoulder movements from neutral into flexion, extension, abduction, adduction and external rotation are easily measured with a goniometer. In the neutral position, the glenohumeral ligaments, which act as the reins of the joint, limit movement and are symmetrically relaxed. The torso obstructs internal rotation with the arm adducted at the side and the full range of movement cannot be attained.
The torso is cleared when the shoulder is abducted, usually to 90°. However, this degree of abduction places the shoulder within the painful arc of impingement and may influence the degree of internal rotation. Further, owing to shoulder joint stiffness, some patients may not be able to abduct the shoulder to 90°. Because of these problems, it has become internationally accepted to measure internal rotation in the near-neutral position by determining the vertebral level behind the back to which the thumb can reach.
We assessed 200 symptomatic and asymptomatic shoulders to determine the correlation between the ‘hand behind back’ and angular measurements of internal rotation at 90° or 30° of abduction.
The abstracts were prepared by Professor M. B. E. Sweet. Correspondence should be addressed to him at The Department of Orthopaedic Surgery, Medical School, University of Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
