Speed-dependent Control of Cyclic Open-Close Movements of the Human Jaw with an External Force Counteracting Closing

Previous work with open-close movements of the jaw in which food resistance was simulated by an external force has shown that additional activity of the jaw-closing muscles to overcome the force is mainly of sensory origin. When the force was expected, a small anticipatory response was also observed...

Full description

Saved in:
Bibliographic Details
Published in:Journal of dental research 1999-04, Vol.78 (4), p.878-886
Main Authors: Abbink, J.H., van der Bilt, A., Bosman, E., van der Glas, H.W.
Format: Article
Language:English
Subjects:
Adult
Biomechanical Phenomena
Dental Stress Analysis - methods
Dental Stress Analysis - statistics & numerical data
Dentistry
Electromyography
Female
Humans
Jaw - physiology
Male
Mastication - physiology
Masticatory Muscles - physiology
Middle Aged
Movement - physiology
Periodicity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Previous work with open-close movements of the jaw in which food resistance was simulated by an external force has shown that additional activity of the jaw-closing muscles to overcome the force is mainly of sensory origin. When the force was expected, a small anticipatory response was also observed, starting before the onset of the force. The movement rates in these experiments corresponded to natural chewing rates of about 60 cycles per minute. Our aim was to investigate how anticipatory and peripherally induced muscle activity change with movement speed. Peripheral feedback to the muscles may increase at higher movement speed, possibly resulting in stronger reflex activity. On the other hand, when the force is expected, more preprogrammed muscle activity may be generated with faster movements, in anticipation of the force. Three movement rates were studied: 30 cpm (slow), 60 cpm (normal speed), and 120 cpm (fast). The results show that muscle activity to move the jaw increases sharply with movement speed. Extra muscle activity needed to overcome the force also increases with movement speed. However, the contribution by peripherally triggered muscle activity does not increase. In contrast, preprogrammed extra muscle activity in anticipation of the force increases sharply with movement speed. It is concluded that the control strategy for these movements is speed-dependent, with a shift to relatively more anticipatory muscle activity at higher movement speeds, making the movement more ballistic.
ISSN:0022-0345
1544-0591
DOI:10.1177/00220345990780040801