Placement of a plate under the forefoot in stance: decreasing the excitability of the soleus motoneuron pool.
OBJECTIVE
To investigate the effect of the placement of a plate under the sole of the forefoot on the excitability of the soleus motoneuron pool in stance.


METHODS
While eight neurologically intact subjects remained in stance, a square plate (30 x 30 mm), either 3 mm or 6 mm in thickness, was placed under the left medial plantar eminence, under the left lateral plantar eminence, or under the left forefoot sole between the eminences, or a rectangular plate (120 x 30 mm), either 3 mm or 6 mm in thickness, was placed under the left metatarsal heads. To investigate the excitability of the soleus motoneuron pool, the Hmax/Mmax ratio was estimated.


RESULTS
Analysis of variance revealed that the region under which the plate was placed had a significant effect and that the thickness of the plate had a nonsignificant effect on the Hmax/Mmax ratio, without significant interaction between the two factors. Post hoc analysis revealed a significant decrease in the Hmax/Mmax ratio when the square plate was placed under the lateral plantar eminence.


CONCLUSIONS
A square plate placed under the lateral plantar eminence inhibited the excitability of the ipsilateral soleus motoneuron pool in stance. This intervention may be useful for reducing spasticity.
Hiraoka
Koichi
K
Department of Physical Therapy, Osaka Prefectural College of Nursing, Habikino, Japan.
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D004558:Electric Stimulation / Q000295:instrumentation* / Q000379:methods; D004576:Electromyography; D004867:Equipment Design; D005260:Female; D005528:Foot / Q000294:innervation* / Q000503:physiopathology; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D008297:Male; D009128:Muscle Spasticity / Q000503:physiopathology / Q000534:rehabilitation*; D018482:Muscle, Skeletal / Q000294:innervation*; D011187:Posture / Q000502:physiology; D013979:Tibial Nerve / Q000503:physiopathology