Toggle Main Menu Toggle Search

Open Access padlockePrints

Alteration of scapula lateral rotation for subjects with the reversed anatomy shoulder replacement and its influence on glenohumeral joint contact force

Lookup NU author(s): Milad Masjedi, Professor Garth Johnson


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


It has previously been reported that motion of the scapula varies for subjects with shoulder joint pathologies and is different from that of normal subjects. In this study, an electromagnetic tracking device was used to measure the three-dimensional scapula motion of nine patients with Bayley-Walker (B-W) reverse anatomy joint replacements. The data were then compared to scapula kinematics of 12 normal subjects with no known shoulder pathology. The scapula kinematics for each subject was determined and a regression analysis to find the mean scapula lateral rotation (SLR) for B-W and normal subjects was performed. The regression model which showed the highest change compared to normal was identified and was used in the biomechanical shoulder model to predict the glenohumeral joint contact force. A high variability of the scapula kinematics was observed, with some subjects having a maximum SLR smaller than that of the normal subjects and some similar to the normal subjects. It was found that scapula may move in such a way to keep the deltoid length at its optimum. The change in the scapula kinematics affected the predicted joint force and its point of application. Hence, knowledge of scapular kinematics is essential for realistic modelling of implanted shoulders.

Publication metadata

Author(s): Masjedi M, Johnson GR

Publication type: Article

Publication status: Published

Journal: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine

Year: 2011

Volume: 225

Issue: H1

Pages: 38-47

ISSN (print): 0954-4119

ISSN (electronic): 2041-3033

Publisher: Professional Engineering Publishing Ltd.


DOI: 10.1243/09544119JEIM789


Altmetrics provided by Altmetric