Akifumi Kiso, MD, Hirofumi Maeda, MD, DMSc, Yohei Otaka, MD, PhD, Hitoshi Mori, PhD, Hitoshi Kagaya, MD, DMSc
Jpn J Compr Rehabil Sci 15: 58-62, 2024
Objective: We have developed a compact device using
a spinning permanent magnet (SPM) that induces
an electrical field by changing the magnetic flux.
We hypothesized that SPM stimulation also reduced
spasticity, comparable with repetitive peripheral magnetic
stimulation (rPMS) and transcutaneous electrical nerve
stimulation (TENS). This study evaluated the effect of a
single session of SPM stimulation and compared it with
those of rPMS and TENS in healthy individuals.
Methods: Eleven healthy adult men participated in
this study. The active electrode was placed on the
soleus muscle, and the reference electrode was placed
at 5 cm distal from the active electrode on the medial
side of the Achilles tendon. The stimulating electrodes
were fixed on the popliteal fossa to stimulate the tibial
nerve. The maximum H-reflex (Hmax) and the maximum
motor response (Mmax) were measured, and Hmax/Mmax
was calculated under the following conditions: a) 15
min SPM stimulation, b) 30 min SPM stimulation, c)
10,000 pulses rPMS, d) 15 min TENS, and e) 15 min
rest (control). The devices for SPM, rPMS, and TENS
were applied to the belly of the soleus muscle in the
prone position.
Results: Compared with the control, Hmax/Mmax
significantly decreased under SPM stimulation for 15
and 30 min, as well as under rPMS and TENS (p <
0.005). The changes in Hmax/Mmax under 15 min SPM
stimulation were significantly smaller than those under
30 min SPM stimulation and rPMS (p < 0.005).
Conclusion: SPM stimulation reduced Hmax/Mmax in
healthy individuals and is a potential new treatment
for spasticity.
Key words: spinning permanent magnet, repetitive peripheral magnetic stimulation, transcutaneous electrical nerve stimulation, Hmax/Mmax