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JOURNAL
OF
SPORTS SCIENCE &
MEDICINE
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Review article
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THE POTENTIAL NEURAL MECHANISMS OF ACUTE INDIRECT VIBRATION |
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Darryl J. Cochrane  |
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School of Sport and Exercise, Massey University, Palmerston North, New Zealand. |
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© Journal of Sports Science and Medicine (2011) 10, 19 - 30 |
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| ABSTRACT | |||
| There is strong evidence to suggest that acute indirect vibration
acts on muscle to enhance force, power, flexibility, balance and proprioception
suggesting neural enhancement. Nevertheless, the neural mechanism(s) of
vibration and its potentiating effect have received little attention. One
proposal suggests that spinal reflexes enhance muscle contraction through
a reflex activity known as tonic vibration stretch reflex (TVR), which increases
muscle activation. However, TVR is based on direct, brief, and high frequency
vibration (>100 Hz) which differs to indirect vibration, which is applied
to the whole body or body parts at lower vibration frequency (5-45 Hz).
Likewise, muscle tuning and neuromuscular aspects are other candidate mechanisms
used to explain the vibration phenomenon. But there is much debate in terms
of identifying which neural mechanism(s) are responsible for acute vibration;
due to a number of studies using various vibration testing protocols. These
protocols include: different methods of application, vibration variables,
training duration, exercise types and a range of population groups. Therefore,
the neural mechanism of acute vibration remain equivocal, but spinal reflexes,
muscle tuning and neuromuscular aspects are all viable factors that may
contribute in different ways to increasing muscular performance. Additional
research is encouraged to determine which neural mechanism(s) and their
contributions are responsible for acute vibration. Testing variables and
vibration applications need to be standardised before reaching a consensus
on which neural mechanism(s) occur during and post-vibration.
Key words: Spinal reflexes, muscle tuning, motor unit firing frequency, motor unit synchronisation, inter-muscular co-ordination. |
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