Original Research
Quantification of Two-Dimensional Glenohumeral Rhythm in Persons With and Without Symptoms of Shoulder Impingement
Am J Orthop. 2008 January;37(1):24-30
Author and Disclosure Information
Wendy S. Burke, DPT, PT, OCS, C. Thomas Vangsness, Jr., MD, and Christopher M. Powers, PhD, PT
Dr. Burke is Assistant Professor of Clinical Research, Department of Biokinesiology and Physical Therapy, Dr. Vangsness is Professor, Department of Orthopaedic Surgery, and Dr. Powers is Associate Professor, Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California.
A repeated-measures design was used to assess glenohumeral rhythm in 10 patients with shoulder impingement and 10 pain-free persons and to assess the effects of subacromial injection on glenohumeral rhythm within the impingement group. Scapular-plane anterior-to-posterior x-rays of the scapula and humerus were obtained at 5 angles of arm elevation (resting, 30°, 60°, 90°, 120°). For the impingement group, x-rays were repeated after subacromial injection (10 mL of 1% lidocaine). No significant differences in glenohumeral rhythm were found between the impingement and control groups across all arm-elevation angles.