In vivo three-dimensional motion analysis of the shoulder joint during internal and external rotation.

ABSTRACT:

Purpose

The purpose of this study was to assess accurately the three-dimensional movements of the scapula and humerus relative to the thorax during internal/external rotation motion with abduction of the shoulder joint.

Methods

Ten right shoulders of ten healthy volunteers were examined using a wide-gantry open magnetic resonance imaging (MRI) system. MRI was performed every 30° from 90° external rotation to 90° internal rotation of the shoulder joint.

Results

The contribution ratio of the scapulothoracic joint was 12.5% about the long axis of the humerus during internal/external rotation motion. With arm position changes from 90° external rotation to 60° internal rotation, most movement was performed by the glenohumeral joint. Conversely, at internal rotation of ≥60°

SUBMITTER: Koishi H 

PROVIDER: S-EPMC3174294 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature