Training-induced changes in the pattern of triceps to biceps activation during reaching tasks after chronic and severe stroke

Barker, R. N., Brauer, S. and Carson, R. (2009) Training-induced changes in the pattern of triceps to biceps activation during reaching tasks after chronic and severe stroke. Experimental Brain Research, 196 4: 483-496. doi:10.1007/s00221-009-1872-8

Author Barker, R. N.
Brauer, S.
Carson, R.
Title Training-induced changes in the pattern of triceps to biceps activation during reaching tasks after chronic and severe stroke
Journal name Experimental Brain Research   Check publisher's open access policy
ISSN 0014-4819
Publication date 2009-07-01
Year available 2009
Sub-type Article (original research)
DOI 10.1007/s00221-009-1872-8
Open Access Status
Volume 196
Issue 4
Start page 483
End page 496
Total pages 14
Editor John C Rothwell
Place of publication Germany
Publisher Springer
Language eng
Subject C1
920201 Allied Health Therapies (excl. Mental Health Services)
110317 Physiotherapy
Abstract This exploratory study was undertaken to investigate the mechanisms that contributed to improvements in upper limb function following a novel training program. Surface electromyography (EMG) was used to examine training-induced changes in the pattern of triceps and biceps activation during reaching tasks in stroke survivors with severe paresis in the chronic stage of recovery. The EMG data were obtained in the context of a single blind randomised clinical trial conducted with 42 stroke survivors with minimal upper limb muscle activity and who were more than 6 months post-stroke. Of the 33 participants who completed the study, 10 received training of reaching using a non-robotic upper limb training device, the SMART Arm, with EMG triggered functional electrical stimulation (EMG-stim), 13 received training of reaching using the SMART Arm alone, and 10 received no intervention. Each intervention group engaged in 12 1-h training sessions over a 4-week period. Clinical and laboratory measures of upper limb function were administered prior to training (0 weeks), at completion (4 weeks) and 2 months (12 weeks) after training. The primary outcome measure was 'upper arm function' which is Item 6 of the Motor Assessment Scale (MAS). Laboratory measures consisted of two multijoint reaching tasks to assess 'maximum isometric force' and 'maximum distance reached'. Surface EMG was used to monitor triceps brachii and biceps brachii during the two reaching tasks. To provide a comparison with normal values, seven healthy adults were tested on one of the reaching tasks according to the same procedure. Study findings demonstrated a statistically significant improvement in upper limb function for stroke participants in the two training groups compared to those who received no training however no difference was found between the two training groups. For the reaching tasks, all stroke participants, when compared to normal healthy adults, exhibited lower triceps and biceps activation and a lower ratio of triceps to biceps activation. Following training, stroke participants demonstrated increased triceps activation and an increased ratio of triceps to biceps activation for the task that was trained. Better performance was associated with greater triceps activation and a higher ratio of triceps to biceps activation. The findings suggest that increased activation of triceps as an agonist and an improved coordination between triceps and biceps could have mediated the observed changes in arm function. The changes in EMG activity were small relative to the changes in arm function indicating that factors, such as the contribution of other muscles of reaching, may also be implicated.
Keyword EMG
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2010 Higher Education Research Data Collection
School of Health and Rehabilitation Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 20 times in Thomson Reuters Web of Science Article | Citations
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Created: Thu, 03 Sep 2009, 17:53:56 EST by Mr Andrew Martlew on behalf of School of Health & Rehabilitation Sciences