Hum Mov Sci, 2020; 72(): 102655, PMID: 32721374 

Acute whole-body vibration reduces post-activation depression in the triceps surae muscle.

Year: 2020

Krause A, Gollhofer A, Lee K, Freyler K, Becker T, Kurz A, Ritzmann R
Institute of Training and Computer Science in Sport, German Sport University Cologne, Germany, Am Sportpark Mungersdorf 6, 50933 Koln; Department for Sports and Sport Science, University of Freiburg, Germany, Schwarzwaldstrasse 175, 79117 Freiburg i.Br.

Abstract

PURPOSE: Acute whole-body vibration (WBV) is known to enhance neuromuscular activation. Especially mechanisms which act presynaptically are discussed to be involved in this modulation, but evidence is still limited. Therefore, this study aimed to investigate if 2 min of WBV might impact the premotoneuronal mechanism of post-activation depression (PAD). METHODS: PAD in m. soleus was assessed by paired-pulse stimulation in 28 healthy participants prior, 2 min, 4 min and 10 min after 2 min of side-alternating WBV (10 Hz, 2 mm). Methodologies involved electromyography (m. soleus, m. tibialis anterior) and goniometric recordings (ankle, knee joint). H-reflexes were elicited with peripheral nerve stimulation and assessed by means of conditioned H-reflexes (ISI 1 s, Hcond) versus control H-reflexes (ISI10, H). RESULTS: Hcond/H was significantly enhanced by +55% (2 min), +32% (4 min) and +35% (10 min) following WBV (P < 0.05). Baseline muscle activity and joint positions were shown to be reliable (Cronbach”s alpha values >0.990) throughout the testing procedure. CONCLUSION: Vibratory-induced spinal inhibition is accompanied by diminished PAD at the presynaptic terminals which interconnect the Ia afferents with the alpha-motoneuron. Functionally, the PAD reduction might explain enhanced motor performance following vibration therapy, but future studies will be needed to verify this assumption.

GID: 5178; Last update: 24.08.2020