Three-dimensional shoulder complex kinematics in individuals with upper extremity impairment from chronic stroke.

PURPOSE To evaluate shoulder complex kinematics in persons with chronic upper extremity (UE) impairments due to stroke and determine if kinematics predicts motor function based on the Fugl-Meyer Motor Assessment (FMA). METHODS Sixteen stroke survivors with chronic UE impairments (age range = 46-80 years, male = 8, female = 8, mean (SD) 66 (40) months post-stroke) performed the UE portion of the FMA with the shoulder/elbow subscale (FM_se) documented. Three-dimensional kinematics of the shoulder complex was collected with the Motion Monitor™ (Innsport, Chicago, IL, USA). Participants performed three repetitions of arm elevation in the frontal, sagittal and self-selected planes. The third repetition was analyzed. Scapular and humeral kinematics were calculated in the self-selected plane. Scapulohumeral rhythm was analyzed at peak elevation. Backward stepwise regression analysis predicted kinematic contributions to the FM_se. RESULTS Mean (SD) FM_se score was 25.3 1(10.9). Peak humeral elevation ranged from 45.6° to 129.2° (median 106.7°). Scapulohumeral rhythm was 4.1:1 when humeral elevation ranged from 45° to 50°, 1.5:1 from 80° to 95° and 2.1:1 from 105° to 130°. Humeral elevation, scapular upward rotation and scapular internal rotation predicted 65.4% of FM_se score variability. CONCLUSIONS Persons with chronic UE impairments from stroke demonstrated reduced peak elevation and altered scapulohumeral rhythm. Three predictors of the FM_se were humeral elevation, scapular upward rotation and scapular internal rotation.