Validation of a video-based motion analysis technique in 3-D dynamic scapular kinematic measurements.
BACKGROUND
Current non-invasive 3-D scapular kinematic measurement techniques such as electromagnetic tracking are subjected to restrictions of wired sensors and limited capture space. Video-based motion analysis provides greater freedom with relatively less movement restriction. However, video-based motion analysis was rarely used in and not validated for scapular kinematics.


METHODS
Scapular kinematics of five subjects performing abduction, scaption, and internal/external rotation was captured simultaneously with video-based motion analysis and dynamic stereo X-ray, a gold standard for tracking scapular movements. The data from video-based motion analysis was correlated with the data from dynamic stereo X-ray for validity evaluation.


RESULTS
Strong and significant correlations were identified in scapular protraction/retraction and medial/lateral rotation during abduction and scaption, and scapular medial/lateral rotation and anterior/posterior tilt during internal/external rotation.


CONCLUSIONS
Video-based motion analysis is valid for evaluating a single subject's scapular movement pattern in protraction/retraction during abduction and scaption, and medial/lateral-rotation during internal/external rotation. Anterior/posterior-tilt during abduction and scaption should be investigated with caution. Video motion analysis is also valid for evaluating group average of scapular kinematics except for protraction/retraction during internal/external rotation. While acknowledging the inherent limitations, video-based motion analysis is an appropriate technique for tracking scapular kinematics.
Neuromuscular Research Laboratory, University of Pittsburgh, 3830 South Water St. Pittsburgh, PA 15203, USA.
Yungchien
Y
Chu
Jon
J
Akins
Mita
M
Lovalekar
Scott
S
Tashman
Scott
S
Lephart
Timothy
T
Sell
D000328:Adult; D001696:Biomechanical Phenomena; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008954:Models, Biological; D009068:Movement / Q000502:physiology*; D011859:Radiography; D012540:Scapula / Q000000981:diagnostic imaging / Q000502:physiology*; D014741:Video Recording