Elucidating the scapulo-humeral rhythm calculation: 3D joint contribution method

作者：Robert Lachaine Xavier^*; Marion Patrick; Godbout Veronique; Bleau Jacinte; Begon Mickael

来源：Computer Methods in Biomechanics and Biomedical Engineering, 2015, 18(3): 249-258.

DOI：10.1080/10255842.2013.792810

• joints
• scapulo-humeral rhythm
• shoulder
• coordination
• kinematics

The scapulo-humeral rhythm quantifies shoulder joint coordination during arm elevation. The common method calculates a ratio of gleno-humeral (GH) elevation to scapulo-thoracic upward rotation angles. However the other rotations also contribute to arm elevation. The objective is to propose a 3D dynamic scapulo-humeral rhythm calculation method including all rotations of the shoulder joints and compare with the common method. Twenty-nine skin markers were placed on the trunk and dominant arm of 14 healthy males to measure shoulder kinematics. Two-way repeated measures ANOVAs were applied to compare the two methods of calculation of joint contributions and scapulo-humeral rhythm during arm elevation. Significant main effects (p<0.05) were observed between methods in joint contribution angles and scapulo-humeral rhythms. A systematic overestimation of the GH contribution was observed when only using the GH elevation angle because the scapula is moved outside a vertical plane. Hence, the proposed 3D method to calculate the scapulo-humeral rhythm allows an improved functional shoulder evaluation.

• 出版日期2015-2-17