The aim of the present experiment was to study how hypnotic susceptibility and hypnosis affect motoneuron excitability. In a first trial, human subjects were selected according to their hypnotic susceptibility. In a second trial, the Hoffmann (H) reflex amplitude of the soleus muscle was studied in 3 groups: (1) highly susceptible subjects during hypnosis with standardized suggestions of simple relaxation, anesthesia, analgesia and paralysis (group I), (2) highly susceptible subjects (group II), and (3) non-susceptible subjects (group III) during long-lasting control conditions.
The aim of the experiment was to assess whether the membrane excitability of flexor cervical and/or lumbar motoneurons is related to hypnotic susceptibility (measured with the Stanford Hypnotic Susceptibility Scale, Form A) and hypnosis. During the experimental sessions, hypnotized subjects were given only suggestions of relaxation (neutral hypnosis) while awake subjects were given instructions to be quiet and relaxed (simple relaxation).
Journal of Manipulative and Physiological Therapeutics
Twenty-seven male and 12 female healthy volunteers were tested twice with 2-7 days separation. Hoffman (H) reflexes and muscle (M) activation waves were obtained from the posterior tibial nerves bilaterally. Results were compared to those obtained from patients presenting with a complaint of low back and/or leg pain, without compressive neuropathy. M, F, H latencies and H/Mmax ratio were recorded. H/M ratio and latency comparisons were not significantly different in the control group left to right or test to test.