Three-dimensional shoulder kinematics to complete activities of daily living.

OBJECTIVE: To describe the contributions of glenohumeral and scapulothoracic joints in performing combing hair, feeding, reaching overhead, washing the back, and washing the contralateral axilla.
DESIGN: A three-dimensional electromagnetic motion capture system was used to collect humerus, scapula, and trunk kinematic data during activities of daily living completion. Descriptive statistics were calculated for the primary humerothoracic motion. Forward multiple regression analyses explained the variation accounted for by glenohumeral and scapulothoracic motions.
RESULTS: The mean internal rotation to accomplish back washing was 85 (standard deviation 24) degrees glenohumeral internal rotation contributed. The mean humerothoracic elevation ranged between 46 (standard deviation 12) degrees for washing the contralateral axilla and 119 (standard deviation 10) degrees for hair combing. Glenohumeral abduction, scapular anterior tipping, and scapular upward rotation contributed to completing feeding, hair combing, reaching overhead, and washing the contralateral axilla. Glenohumeral flexion contributed to completing feeding, reaching overhead, and washing the contralateral axilla. Scapular internal rotation contributed to completing feeding.
CONCLUSIONS: Glenohumeral abduction and scapulothoracic upward rotation were necessary to accomplish feeding, combing hair, reaching overhead, and washing the contralateral axilla. Glenohumeral internal rotation was necessary to accomplish back washing. Interventions addressing glenohumeral and scapulothoracic motions in patients who are having difficulty in completing activities of daily livings may prove beneficial.