Shoulder complex position and glenohumeral subluxation in hemiplegia

Abstract

Objectives: 1. To determine if scapular and humeral orientation differed between the affected and nonaffected side in two groups of hemiplegic subjects (low tone and high tone). 2. To determine if there was a relationship between these measures and glenohumeral subluxation in either group. Design: Retrospective case-comparison study. Subjects, Setting: Thirty-four hemiplegic subjects, 41 to 89 years of age, participated in the study. Subjects were divided into high-tone ( n = 17) and low-tone ( n = 17) groups on the basis of Ashworth scoring of muscle tone. Outcome Measures: Linear and angular measures of scapular and humeral orientation were calculated from tridimensional coordinates of bony landmarks collected using an electromagnetic device with subjects in a seated position with arms relaxed by their side. Glenohumeral subluxation was measured from radiographs. Results: The scapula was further from the midline and lower on the thorax on the affected side in the low-tone group ( p < .05). Glenohumeral subluxation was greater in the low-tone group ( p < .05). The scapular abduction angle (ScAb) was significantly greater on the nonaffected in the low-tone group compared with both the affected side in this group and to the nonaffected side in the high-tone group. In the high-tone group, no differences were found between the affected and nonaffected side in either the angular or linear measures. There was no significant correlation between scapular or humeral orientation and glenohumeral subluxation in either group ( p > .05). Conclusions: This study provided little evidence of a consistent pattern of alteration in shoulder complex orientation, particularly in subjects with increased muscle tone, and no support for the concept of a relationship between scapular and humeral orientation and glenohumeral subluxation.