Northampton Electronic Collection of Theses and Research

Plantarflexor stretch training increases reciprocal inhibition measured during voluntary dorsiflexion

Blazevich, A. J., Kay, A. D., Waugh, C., Fath, F., Miller, S. and Cannavan, D. (2012) Plantarflexor stretch training increases reciprocal inhibition measured during voluntary dorsiflexion. Journal of Neurophysiology. 107(1), pp. 250-256. 0022-3077.

Item Type: Article
Abstract: Agonist-mediated reciprocal inhibition (RI) in distal skeletal muscles is an important neurophysiological phenomenon leading to improved movement coordination and efficiency. It has been shown to be reduced in aged and clinical populations, so the development of interventions augmenting RI is an important research goal. We examined the efficacy of using chronic passive muscle stretching to augment RI. The influence of 3 wk of plantarflexor stretching (4 × 30 s, two times/day) on RI of soleus and gastrocnemius initiated by tonic, voluntary dorsiflexion contractions [20% of maximum voluntary contraction (MVC)] was examined in 11 healthy men who performed stretch training and in nine nontraining controls. Hoffmann's reflexes (H-reflexes) were elicited by tibial nerve stimulation during both weak isometric (2% MVC) plantarflexions and dorsiflexion contractions at 20% MVC. Changes were examined at three joint angles, normalized to each subject's range of motion (ROM; plantarflexed = 10 ± 0°, neutral = −3.3 ± 2.9°, dorsiflexed = −16.5 ± 5.6°). No changes were detected in controls. A 20% increase in ROM in the stretch subjects was associated with a significant decrease in maximum H-reflex (Hmax): maximum evoked potential (Mmax), measured during 2% plantarflexion at the plantarflexed and neutral angles in soleus and at the plantarflexed angle in gastrocnemius (P < 0.05–0.01). By contrast, decreases in Hmax:Mmax during 20% dorsiflexion contract were also seen at each angle in soleus and at the dorsiflexed angle in gastrocnemius. However, a greater decrease in Hmax:Mmax measured during voluntary dorsiflexion rather than during plantarflexion, which indicates a specific change in RI, was detected only at the dorsiflexed angle (−30.7 ± 9.4% and −35.8 ± 6.8% for soleus and gastrocnemius, respectively). These results demonstrate the efficacy of soleus-gastrocnemius stretch training in increasing agonist-mediated RI from tibialis anterior onto soleus-gastrocnemius in young, healthy individuals at dorsiflexed, but not plantarflexed, joint angles.
Uncontrolled Keywords: static stretch, electrical stimulation, tibial nerve, soleus, skeletal muscle
Subjects: Q Science > QP Physiology > QP351 Neurophysiology and neuropsychology
Q Science > QP Physiology > QP301 Exercise and sports physiology
Creators: Blazevich, Anthony J, Kay, Anthony D, Waugh, C, Fath, F, Miller, S and Cannavan, D
Publisher: American Physiological Society
Faculties, Divisions and Institutes: University Faculties, Divisions and Research Centres - OLD > Faculty of Health & Society > Sports, Exercise & Life Sciences
University Faculties, Divisions and Research Centres - OLD > Research Centre > Institute of Health and Wellbeing > Centre for Physical Activity and Chronic Disease
Faculties > Faculty of Health & Society > Sports, Exercise & Life Sciences
Research Centres > Centre for Health Sciences and Services
Research Centres > Centre for Physical Activity and Life Sciences
Date: 5 January 2012
Date Type: Publication
Page Range: pp. 250-256
Journal or Publication Title: Journal of Neurophysiology
Volume: 107
Number: 1
Language: English
ISSN: 0022-3077
Status: Published / Disseminated

Actions (login required)

Edit Item Edit Item