起立姿勢における下肢拮抗筋活動性の種々相

The EMG's of the antagonists of the lower limbs in Romberg's position were recorded in normal subjects as well as patients with disequilibrium and the records were evaluated in relation to bodily equilibrium. The antagonists referred to herein were the anterior tibial muscles and gastrocnemius muscles and the myographic recording was made using surface electrodes. Furthermore, in some patients, the EMG records were compared to the results of the following tests: statokinesimetry, functional tests for autonomic reactions in the central nervous system and psychological and/or psychiatric examinations.<br>The following facts were noted:<br>(1) The EMG's thus obtained were classified into the following 5 types, type I, II, III, IV and V. In type I, the EMG's were never found in any of the muscles tested. In type II, the EMG's developed in the bilateral anterior tibial muscles, whereas in type III, they developed in the bilateral gastrocnemius muscles. In type IV, the EMG's developed in the anterior tibial muscles and gastrocnemius muscles and with a crossed combination. In type V, the EMG's were observed in all the muscles tested.<br>(2) Type I was mainly observed in normal subjects, whereas the other types were observed in patients with disequilibrium. Type III was often observed in patients with disequilibrium of slight degree, whereas type V was usually observed in patients with marked disequilibrium. Type IV was between types III and V with regard to the severity of disequilibrium. Thus, it was noted that the type of the above-mentioned EMG's altered in accord with the severity of the disequilibrium. However, type II was particular in nature and such was sometimes observed in neurotic patients.<br>(3) A certain correlation was found between the above-mentioned types of EMG's and the results of the equilibrium test with adrenaline loading of Hinoki. For instance, patients with types II and III showed poor positive signs of the equilibrium test with adrenaline loading, whereas those with type V often showed positive signs of this equilibrium test. These findings suggest that there is a certain correlation between the above-mentioned types of EMG's and the activity of adrenergic components in the central nervous system.<br>(4) A positive correlation was found between the above-mentioned types of EMG's and the size and/or pattern of the sway of the center of gravity when the Romberg test was carried out. For instance, type III tended to relate to the development of the sway of the center of gravity where the size of the sway was within the normal limit and the pattern of the sway showed the centric form. In contrast, type V tended to relate to the development of the sway of the center of gravity where the size of the sway exceeded the normal limit and the pattern of the sway showed diffuse and/or back and forth forms.<br>From these results, we postulate:<br>Electromyographic analysis of the antagonists of the lower limbs in Romberg's position is useful for the determination of the severity of disequilibrium and, moreover, is also useful for objective description of alteration of disequilibrium in the course of treatment. Furthermore, the above-mentioned EMG test seems also valuable for the determination of the locus of lesions in the equilibrium system as well as the characteristics of the disequilibrium when it is carried out in combination with the following tests: the statokinesimetry, functional tests for autonomic reactions in the central nervous system, psychological and/or psychiatric examinations.