the effect of spinal skin cooling with topical ointment on the recruitment curve parameters of soleus h-reflex

introduction : there are different applications for cooling in rehabilitation and there is also a controversy in results of applying ice on limb and its effects on motorneurons excitability. methods : this study was done to determine the effect of applying controlled cooling (rubbing cold ointment with 3°c temperature) on the spinal skin (around t place of s root nerve) on the excitability of soleus 11, 11 motorneurons in ten healthy, non-athletic men. each volunteer was tested in two [control (vazeline ointment with - environment temperature) and examination (cold vazeline)] separate sessions. we used soleus h-reflex and m h wave recruitment curve parameters for evaluation. stimulation current was a square pulse with 700 microsecond duration and 0.2 hz frequency. h-reflex was recorded with 9 different amplitudes. results: fit l slope, fit l slope and peak to peak amplitude of h-reflex decreased immediately and 30 3 5 minutes after the application of cold ointment. conclusion: cold by stimulating the thermoreceptors and reducing the firing rate of surface mechanoreceptors can decrease the excitability of motoneurons and this effect may be long lasting.