Stuttering is a serious disorder of speechfl uency. The manifestations include a superfluous increase of muscular tension, which originates not only on vocal cords, but may be generalized into skeletal muscles of the whole body and become manifest even by clonic spasms. Some authors are of the opinion that increased tension of laryngealmuscles, leading to the occlusion of glottis, corresponds to the mechanism of Valsalve maneuver, which participates in the development of the stuttering. The opinion was coined by Perry, who had suffered from stuttering from his childhood and was treated with various procedures without success. He elaborated, and claimed to have experienced himself the method for the treatment of stuttering, which evokes fluent speech by suppressing the mechanisms of the Valsalve maneuver. The method is based on suppressing the activity of abdominal and thoracic muscles, which brings about a soft beginning, while practice of speechena ble to bind individual words and syllables. In a clinical examination of the stuttering patient withtonic manifestations in the speechres ulting even into long initial tones and speech blocks clearly indicates that the mechanism of the Valsalve maneuver indeed becomes manifest during the stuttering attack.We therefore decided tomake an objective study of the influence of the Valsalve experiment on the motor activities by determining the effects of the Valsalve maneuver on mono-synaptic reflex activity of spinal cord in the S1 segment by means of electrically evoked mono-synaptic reflex of spinal cord (Hoffmann’s reflex, so called H-reflex). The amplitude of the H-reflex was followed at rest as well as in the course of the Valsalve maneuver. It became obvious that the H-reflex amplitude increased during the Valsalve experiment, the increase being statistically significant at 5% probability level. The increase of H-reflex amplitude in the course of the Valsalve maneuver is apparently due to increased flow of afferent impulses as a consequence of generalized increase in muscular tension and muscular strain, which is the basis of the Valsalve maneuver. This increased afferentation then follows to increased excitability of motor cells at the spinal and supraspinal level. This kind of increased excitability then makes it possible to maintain a high level of muscular tonus, which follows to improved muscular strength, consequently to quantitative improvement of motor effectiveness. At the same time this increase deteriorates a precise coordination of minute motions, and consequently the qualitative aspect of fine motor activity, which is under great demands especially during motor realization of speech. The mechanisms of the Valsalve maneuver therefore clearly participate in the evolution of stuttering attack, although they are neither the cause nor decisive. An increased excitability of motor system and decreased fine motor activity is muchmore pronounced as a consequence of spreading negative emotion, which originates during the stuttering attack and influences the reflex motor activity more than the Valsalve maneuver. The principles of therapeutic procedure based on intentional suppression of themechanism of the Valsalve maneuver may have favorable results, though.A more detailed analysis of the therapeutic method, as recommended by its supporters, indicate many common features shared with other methods. In particular, the principles are similar to a series of other procedures including the Seemans method of complex traetment of stuttering.

        Key words: Valsalve maneuver, fluent speech, respiratory pathways, muscular activity.