Research

An explorative, cross-sectional study into abnormal muscular coupling during reach in chronic stroke patients

Gerdienke B Prange¹ , Michiel JA Jannink^1,2 , Arno HA Stienen^2,3 , Herman van der Kooij^2,4 , Maarten J IJzerman⁵ and Hermie J Hermens^1,6

¹  Roessingh Research & Development, Roessinghsbleekweg 33b, Enschede, the Netherlands

²  University of Twente, Department of Biomechanical Engineering, Drienerlolaan 5, Enschede, the Netherlands

³  Northwestern University, Department of Physical Therapy & Human Movement Science, 645 North Michigan Avenue, Chicago (IL), USA

⁴  Delft University of Technology, Department of Biomechanical Engineering, Stevinweg 1, Delft, the Netherlands

⁵  University of Twente, Department of Health Technology & Services Research, Drienerlolaan 5, Enschede, the Netherlands

⁶  University of Twente, Department of Electrical Engineering, Mathematics and Computer Science, Drienerlolaan 5, Enschede, the Netherlands

author email corresponding author email

Journal of NeuroEngineering and Rehabilitation 2010, 7:14doi:10.1186/1743-0003-7-14

Published:	16 March 2010

Abstract

Background

In many stroke patients arm function is limited, which can be related to an abnormal coupling between shoulder and elbow joints. The extent to which this can be translated to activities of daily life (ADL), in terms of muscle activation during ADL-like movements, is rather unknown. Therefore, the present study examined the occurrence of abnormal coupling on functional, ADL-like reaching movements of chronic stroke patients by comparison with healthy persons.

Methods

Upward multi-joint reaching movements (20 repetitions at a self-selected speed to resemble ADL) were compared in two conditions: once facilitated by arm weight compensation and once resisted to provoke a potential abnormal coupling. Changes in movement performance (joint angles) and muscle activation (amplitude of activity and co-activation) between conditions were compared between healthy persons and stroke patients using a repeated measures ANOVA.

Results

The present study showed slight changes in joint excursion and muscle activation of stroke patients due to shoulder elevation resistance during functional reach. Remarkably, in healthy persons similar changes were observed. Even the results of a sub-group of the more impaired stroke patients did not point to an abnormal coupling between shoulder elevation and elbow flexion during functional reach.

Conclusions

The present findings suggest that in mildly and moderately affected chronic stroke patients ADL-like arm movements are not substantially affected by abnormal synergistic coupling. In this case, it is implied that other major contributors to limitations in functional use of the arm should be identified and targeted individually in rehabilitation, to improve use of the arm in activities of daily living.