Effect of stimulation of cold receptors with menthol on EMG activity of quadriceps muscle during low load contraction.
Facilitatory and inhibitory responses of spinal motor neurons are influenced by somatosensory input from the skin. The purpose of this study, employing electromyography, was to examine the neuromuscular changes that occur with menthol applied to the skin over the quadriceps muscle.



Forty-two healthy volunteers performed isometric knee extensions at 35% maximum voluntary contraction (MVC) in three groups (Adult Placebo, Adult Menthol, Older Adult Menthol). Stimulation used was application of 5% menthol gel to the skin. Surface electromyography (sEMG) from the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) was recorded using miniature pair electrodes.



Root mean square electromyography (rmsEMG) in VL and VM significantly increased with menthol stimulation both in Adult and Older Adult, but no significant difference was observed between Adult Menthol and Older Adult Menthol. There was a significant decrease in mean power frequency (MPF) in VM with menthol stimulation in Older Adult, but no significant changes were observed in Adult Menthol.



Neuromuscular modulation was observed with the application of menthol gel at low loads in the present study. These findings could lead to a new method of muscular training that targets the recruitment of fast type muscle safe for older adults.
a Personal Health Care Products Research Laboratories, Kao Corporation , Tokyo , Japan.|b School of Medicine, Toho University , Tokyo , Japan.
Tadayuki
T
Tokunaga
b School of Medicine, Toho University , Tokyo , Japan.|c Department of Physical Therapy , Tokyo University of Technology , Tokyo , Japan.
Hitoshi
H
Sugawara
b School of Medicine, Toho University , Tokyo , Japan.
Chigaya
C
Tadano
b School of Medicine, Toho University , Tokyo , Japan.
Masuo
M
Muro
D000328:Adult; D000368:Aged; D004576:Electromyography; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008610:Menthol / Q000494:pharmacology*; D008875:Middle Aged; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D052097:Quadriceps Muscle / Q000187:drug effects / Q000502:physiology*; D012867:Skin / Q000187:drug effects / Q000294:innervation; D013823:Thermoreceptors / Q000187:drug effects / Q000378:metabolism*; D055815:Young Adult
D008610:Menthol
Cold receptors; TRPM8 channel; menthol; muscle activation; older adults