Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/42933
Title: Responses to whole head-and-body tilts with and without passive ankle dorsiflexion in the absence of visual feedback
Authors: Lomonaco, LA
Paquet, N
Hui-Chan, CWY
Keywords: Balance
Head-body tilt
Ankle dorsiflexion
Electromyography
Human
Issue Date: 2004
Publisher: Pergamon Press
Source: Clinical biomechanics, 2004, v. 19, no. 6, p. 648-652 How to cite?
Journal: Clinical biomechanics 
Abstract: Objectives. We have investigated lower limb responses in seven blindfolded healthy subjects to well controlled tilts in the standing position. Our aims were (1) to determine the effect of head acceleration magnitude on responses evoked by whole head-and-body tilts, and (2) to establish whether tilt-evoked responses are modifiable by passive ankle dorsiflexion. Whole head-and-body tilts evoked responses in the biceps femoris, medial gastrocnemius and tibialis anterior muscles.
Methods. Seven young healthy subjects stood on a spring-activated tilting apparatus and underwent sudden whole head-and-body tilts of about 15° from the vertical position, with or without passive ankle dorsiflexion. Head acceleration was recorded with a linear accelerometer and ankle angular displacement with a potentiometer. Surface EMG signals were recorded in the right biceps femoris, medial gastrocnemius and tibialis anterior muscles.
Results. As the peak of head acceleration was increased from 0.5g to 1.8g, the frequency of occurrence of tilt-evoked responses increased from 7% to 60% of trials in the biceps femoris muscle during whole head-and-body tilts. In general, the more proximal muscle (biceps femoris) was activated before the more distal muscle (medial gastrocnemius) during whole head-and-body tilts, while the opposite pattern was found during tilt with dorsiflexion.
Conclusions. Our results indicate that the occurrence of tilt-evoked responses increases with an increase in the amplitude of tilting acceleration. This suggests that tilt-evoked responses are dependent, at least in part, on vestibular stimulation. In addition, the spatio-temporal pattern of biceps femoris and medial gastrocnemius muscle activation was opposite during whole head-and-body tilts and tilts with dorsiflexion. This finding suggests that foot/ankle somatosensory inputs can modify tilt-evoked responses.
URI: http://hdl.handle.net/10397/42933
ISSN: 0268-0033
EISSN: 1879-1271
DOI: 10.1016/j.clinbiomech.2004.03.007
Appears in Collections:Journal/Magazine Article

Access
View full-text via PolyU eLinks SFX Query
Show full item record

Page view(s)

10
Last Week
0
Last month
Checked on Jun 18, 2017

Google ScholarTM

Check

Altmetric



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.