Shoulder Movement and Pain after Stroke

Movement patterns of the scapula and humerus in people with HSP have been investigated in four studies to date. Several studies of the kinematics of humeral elevation have found that scapular upward rotation is increased in subjects with HSP.[15- 17] A fourth study, however, found that scapular upward rotation was variable in this population.[18] Scapular tilt does not appear to be abnormal in people with HSP compared to controls. Passive humeral external rotation has been examined [15, 19-21], however dynamic humeral external rotation during humeral elevation has yet to be 28studied. Because patient reports of pain are greater with movement than at rest [3-5], it is critical to examine humeral external rotation dynamically during shoulder elevation. The first purpose of this study was to examine the scapular and humeral movement patterns in people with hemiparetic shoulder pain, particularly humeral external rotation. The second purpose of this study was to examine the relationship between reports of pain and abnormal scapular and humeral movement. We used an electromagnetic tracking system to study the kinematics of subjects with HSP and age-matched neurologically intact control subjects as they elevated their affected, contralesional arm. We hypothesized that subjects with HSP would have abnormal scapular and humeral movement patterns compared to controls. Specifically we expected to see increased scapular upward rotation (as been found previously) and decreased humeral external rotation. We also anticipated that severity of pain would be related to the extent of the abnormal movement patterns