Tonic vibration reflex
Encyclopedia
Tonic vibration reflex is a sustained contraction of a muscle
subjected to vibration. This reflex is caused by vibratory activation of muscle spindles — muscle receptors sensitive to stretch.
Tonic vibration reflex is evoked by placing a vibrator
— which in this case is typically an electrical motor with an eccentric load on its shaft — on a muscle's tendon. 30–100 Hz vibration activates receptors of the skin, tendons and, most importantly, muscle spindles. Muscle spindle discharges are sent to the spinal cord through afferent
nerve fibers, where they activate monosynaptic and polysynaptic reflex
arcs, causing the muscle to contract.
The effects of sustained vibratory stimulation on muscle contraction, posture
and kinesthetic perception
s are much more complex than merely contraction of the muscle being vibrated.
Russian scientists Victor Gurfinkel, Mikhail Lebedev, Andrew Polyakov and Yuri Levick used vibratory stimulation to study human posture control and spectral characteristics of electromyographic (EMG) activity.
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
subjected to vibration. This reflex is caused by vibratory activation of muscle spindles — muscle receptors sensitive to stretch.
Tonic vibration reflex is evoked by placing a vibrator
Vibrator (mechanical)
A vibrator is a mechanical device to generate vibrations. The vibration is often generated by an electric motor with an unbalanced mass on its driveshaft.There are many different types of vibrator...
— which in this case is typically an electrical motor with an eccentric load on its shaft — on a muscle's tendon. 30–100 Hz vibration activates receptors of the skin, tendons and, most importantly, muscle spindles. Muscle spindle discharges are sent to the spinal cord through afferent
Afferent
Afferent is an anatomical term with the following meanings:*Conveying towards a center, for example the afferent arterioles conveying blood towards the Bowman's capsule in the Kidney. Opposite to Efferent.*Something that so conducts, see Afferent nerve fiber...
nerve fibers, where they activate monosynaptic and polysynaptic reflex
Reflex
A reflex action, also known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus. A true reflex is a behavior which is mediated via the reflex arc; this does not apply to casual uses of the term 'reflex'.-See also:...
arcs, causing the muscle to contract.
The effects of sustained vibratory stimulation on muscle contraction, posture
Human position
Human positions refers to the different positions that the human body can take.There are several synonyms that refer to the human position, often used interchangeably, but having specific flavors....
and kinesthetic perception
Perception
Perception is the process of attaining awareness or understanding of the environment by organizing and interpreting sensory information. All perception involves signals in the nervous system, which in turn result from physical stimulation of the sense organs...
s are much more complex than merely contraction of the muscle being vibrated.
Russian scientists Victor Gurfinkel, Mikhail Lebedev, Andrew Polyakov and Yuri Levick used vibratory stimulation to study human posture control and spectral characteristics of electromyographic (EMG) activity.