The responses of human muscle spindle endings to vibration of non‐contracting muscles.

Abstract

SUMMARY1. In micro-electrode recordings from the human peroneal and tibial nerves, the responses of thirty-two primary spindle endings, thirteen secondary spindle endings and three Golgi tendon organs were studied during vibration of the tendons of the receptor-bearing muscles in the leg. The amplitude of the applied vibration was 1-5 mm and the frequency was varied from 20 to 220 Hz. As checked with e.m.g. and torque measurements, the muscles of the leg were relaxed during the sequences analysed.2. Providing that the vibrator was accurately applied, all endings responded with discharges phase-locked to the vibration cycles, the discharge rates being at the vibration frequency or at subharmonics of that frequency. The response to vibration was of abrupt onset and offset, was maintained for the duration of vibration, and was not subject to fluctuation with changes in attention or with remote muscle contraction.3. The maximal discharge rate that could be achieved varied from one ending to the next, and increased with the length of the receptor-bearing muscle. For endings driven at their maximal rate an increase in vibration frequency produced a decrease in discharge rate as the ending changed to a subharmonic pattern of response. The converse occurred on decreasing vibration frequency.' 4. For any given muscle length, primary endings could generally be driven to higher rates than secondary endings but there was a wide range of responsiveness within each group and a significant overlap between the groups. At medium muscle length, the most responsive primary endings could be driven up to 220 Hz but secondary endings did not reach discharge rates higher than 100 Hz. 5. With combined vibration and passive movements, primary endings

Whole-Body-Vibration–Induced Increase in Leg Muscle Activity During Different Squat Exercises

“…Second, it is hypothesized that the magnitude of the WBV-induced increase in leg muscle activity will depend on the type of squat exercise performed on the vibrating platform. The sensitivity of the muscle spindles, which are assumed to be the main contributors to the reflex muscle activation (12,14), is higher in stretched muscles and preactivated muscles (4,5). Therefore, it is expected that an exercise inducing a high stretch or a high preactivation of the receptor-bearing muscle will result in a larger increase in muscle activity during WBV as compared with an exercise with a shorter or more relaxed state of that muscle.…”

Vibration-Induced Nystagmus in Patients with Unilateral Peripheral Vestibular Disorders

“…Muscle vibration activates the primary endings of the muscle spindles. The response of the muscle spindles to vibration shows an abrupt onset and offset [24]. VIN showed an abrupt onset and offset, and the VIN did not persist after vibratory stimulation ceased.…”

The efficacy of manual versus local vibratory massage in promoting recovery from post-exercise muscle damage – A systematic review

“…Ayles et al (2011) have recently suggested that the positive effect of VT in attenuating DOMS could be due to the stimulation of muscle spindles and increase in its afferent activity that is caused by vibration; that vibration reduces the perception of pain through same mechanism of pain gait theory, leading to increase in background tension and motor unit activity (Weerapong et al, 2005). As mentioned on page 72, the isolated muscle or tendon vibration could lead to activation of primary and secondary muscle spindle endings so as the Iβ afferents from GTOs (Burke et al, 1976). It also reduces Iα afferent transmission because of an increased level of presynaptic inhibition.…”