Differences in scapular kinematics and scapulohumeral rhythm during elevation and lowering of the arm between typical children and healthy adults

Abstract

Scapular kinematics in healthy adults is well described in the literature but little is known on typical children. This study aimed to compare the three-dimensional (3-D) scapular kinematics and scapulohumeral rhythm during the elevation and lowering of the arm in the scapular plane in typical children and healthy adults. Twenty-six healthy adults (35.34±11.65years, 1.70±0.10m, 70.00±12.30kg) and 33 typical children (9.12±1.51years, 1.40±0.10m, 35.40±10.45kg) participated in this study. 3-D scapular kinematics were obtained using an electromagnetic tracking device. The subjects were asked to elevate and lower their arm in the scapular plane. Children showed less scapular protraction compared to adults at 120° during arm elevation, more anterior tilt than adults in the elevation and also at 60°, 90° and 120° during lowering of the arm. Children also showed higher scapulohumeral rhythm during lowering of the arm compared to adults from 90° to 60°. It was also found a low to little correlation between scapular position and age. The study showed small but significant differences in scapular kinematics and scapulohumeral rhythm between children and adults. These results can help clinicians to improve diagnosis and treatment protocols directed to children with dysfunction, as reference values on scapular kinematics in healthy children are also provided in this study.