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

Abstract

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.

Implications for Rehabilitation

• Three-dimensional analyses of shoulder elevation in stroke survivors with chronic upper extremity impairments reveal altered scapulohumeral rhythm in their paretic limb.

• Those with greater elevation limitations demonstrate larger scapular contribution. Humeral elevation, scapular upward rotation and scapular internal rotation predict motor function as measured by the Fugl-Meyer Motor Assessment.

• Clinicians should include examination of and intervention to all the components of the shoulder complex to address functional deficits.

Keywords:

• Kinematics
• motor function
• shoulder
• stroke

Declaration of interest: The authors report no conflicts of interest.