As the no-mirror condition increased the demand on vestibular and proprioceptive feedback, this activation may have served to increase [alpha]-[gamma] co-activation and subsequently
muscle spindle sensitivity surrounding the ankle joint.
For the
muscle spindle measurements, images (magnification of 1000X) of the same
muscle spindle were captured in 10 different cuts per animal.
Some studies commented that low vibration frequency (5-45 Hz) has been efficient to increase EMG activity, muscle force, and power possibly by excitatory responses of the
muscle spindle enhance muscle activation that involve a spinal reflex mechanism (6,9,10).
Paraspinal
muscle spindle responses to the duration of a spinal manipulation under force control.
The receptor portion of the
muscle spindle is located midway between its ends where the intrafusal muscle fibres have no contractile element.
Histologic features were consistent with leiomyoma with the presence of smooth
muscle spindle cells without necrosis, atypical nuclei, or mitotic figures.
(1978)
Muscle spindle responses in man to changes in load during accurate position maintenance.
Evidence for presynaptic inhibition of
muscle spindle Ia afferents in man.
As ACE Certified News points out, "[T]his activation inhibits
muscle spindle activity, turning off neural and muscle activity to promote connective tissue elongation.
Whole body vibration (WBV) is a current neuromuscular training method, which even at a low intensity provokes muscle length changes that stimulate the sensory receptor of the
muscle spindle.
The mechanism of action of US for reduction of skeletal muscle spasm may rely on thermal effects that alter the skeletal muscle contractile process, reduce
muscle spindle activity, or break the pain-spasm-pain cycle (Michlovitz, 1990).
Boyd-Clark LC, Briggs CA and Galea MP (2002):
Muscle spindle distribution, morphology, and density in longus colli and multifidus muscles of the cervical spine.