Функциональная характеристика Н-рефлекса и М-ответа у акробатов, испытывающих боли в поясничном отделе

The paper presents the results of electroneuromyographic studies on excitability of spinal motoneurons innervating the gastrocnemius and soleus muscles of the lower leg in 12-17-year-old acrobats experiencing pains in the lumbar area. We show that at frequent compression of intervertebral discs, peripheral nerve fibers undergo deformations accompanied by the following changes (that indicate the severity of damage to the sensory and motor nerve fibers): higher excitability threshold of these fibers, longer latency period of H-reflexes, and shorter duration and amplitude of M-responses. We also found that changes in the inflow of afferent information are accompanied by a decrease in the spinal reflex excitability of alpha motoneurons. Raised threshold of sensory nerve fibers excitability, longer latent period of H-reflex and its shorter duration may indicate a decrease in the number of 1α sensory fibers and (or) their thinning.Based on the studies, we detected sets of lesions in the peripheral nerves corresponding to the localization of the altered vertebral motor segment.