Measurement of the Shoulder Motion Using 3-D Motion Capture Technique

Kim, Ha Yong; Lee, Sang Min; Lee, Sang Ki; Lee, Kwang Won; Kim, Choon Myeon; Choy, Won Sik

Abstract

PURPOSE
Measurement of scapular motion as a component of shoulder motion is clinically limited. The purpose of this study was to measure the scapulothoracic motion and glenohumeral motion separately using the 3-D motion capture technique.
MATERIALS AND METHODS
Twelve healthy adult male volunteers (Mean age: 28 years) without any history of shoulder pathologies were included for the study. Shoulder motions in 3 planes -forward flexion, abduction in scapular plane and abduction in coronal plane- were measured in 3-dimensions. And we estimated skin slippage of optical markers according to the flexion of the shoulder using ultrasonography.
RESULTS
During forward flexion, abduction in scapular plane and abduction on coronal plane, scapula showed upward rotation, external rotation and posterior tilting. Especially, during abduction on coronal or scapula plane, scapula was upwardly rotated and posteriorly tilted in linear fashion. The scapulo-humeral rhythm was 6.7:1 in whole range of abduction on the coronal and scapular plane. Estimated skin slippage of the marker on the inferior angle of scapula was 4.3+/-1.7 cm and bigger than those of other markers.
CONCLUSION
This study failed to get a useful data of shoulder motion due to marker position which did not reflect scapula motion actually. But this trial could be a help for the future study, as this study suggested the possibilities of 3-D motion capture technique for the measurement of shoulder motion.