Research Article
Roberto Casale, Francesco Cecc
Abstract
Acupuncture or dry needling, in clinical practice have been used successfully in the treatment of pain associated with muscle tone alterations. However a possible direct effect on muscle tone has never been clearly separated from its analgesic action. The H-reflex is a recognised neurophysiological index of the excitability of spinal motor neuron pool. This reflex is highly inhibited by the application of a vibration stimulus of 100 Hz. The aim of the study was to evaluate in a group of normal subjects and in absence of pain if acupuncture stimulation was capable of acting at the segmental level, modifying the 100 Hz vibratory inhibition of the H-reflex. H-reflex amplitude significantly varied in relation to the application of vibratory stimulus and acupuncture stimuli. Before vibration (H-Basal) the average amplitude was 292 ± 59.3 μV. During vibration (H-Vib) the amplitude reduced to 118 ± 73.6 μV (H-Bas vs. H-Vib p<0.05). Insertion of the needle (H-Vib+needle) produced a statistically significant increase in amplitude of the H-reflex to 218.8 ± 95 μV (H-Vib vs. H-Vib+Ago p<0.05). Through the use of neurophysiological techniques on man e.g. H-reflex, the existence of a direct effect of acupuncture on the excitability of the spinal motor neurons has been demonstrated suggesting an action of acupuncture on muscle tone separate from its well-known analgesic effect.