THE CONTROL OF SHOULDER MUSCLES DURING GOAL-DIRECTED MOVEMENTS, AN INVERSE DYNAMIC ANALYSIS

Citation
R. Happee et Fct. Vanderhelm, THE CONTROL OF SHOULDER MUSCLES DURING GOAL-DIRECTED MOVEMENTS, AN INVERSE DYNAMIC ANALYSIS, Journal of biomechanics, 28(10), 1995, pp. 1179-1191
Citations number
35
Categorie Soggetti
Engineering, Biomedical",Biophysics
Journal title
ISSN journal
00219290
Volume
28
Issue
10
Year of publication
1995
Pages
1179 - 1191
Database
ISI
SICI code
0021-9290(1995)28:10<1179:TCOSMD>2.0.ZU;2-0
Abstract
Fast goal directed arm movements in the sagittal plane were analyzed w ith a three-dimensional shoulder model with 95 muscle elements, Dynami cs of the muscle elements were described by a third-order nonlinear mu scle model. Muscle forces and activation were estimated using the meth od of inverse muscular dynamics, an optimization scheme which uses onl y very limited computational power. Most model results were similar to the EMG but some differences between model results and EMG were found in muscles where the EMG activity was subject dependent. For the move ment studied, the thoracoscapular muscles were shown to deliver about 40% of the energy required for the acceleration of the arm during ante flexion and about 22% during retroflexion. Activity of thoracoscapular muscles was also required to ensure contact between the thorax and th e scapula which is important for the mechanical stability of the shoul der. The rotator cuff muscles were found to deliver about 19% of the e nergy required for the acceleration of the arm during anteflexion and about 8% during retroflexion.