The author observed the changes in electromyographic patterns of 14 patients with rheumatoid arthritis (13 cases of classical rheumatoid arthritis and one case of definite rheumatoid arthritis) bathed 2 or 3 times daily in hot spring water at Misasa Spa, at a temperature of 40±1℃, 5-10 minutes. The electromyographic examination was performed on the biceps brachii, opponens pollicis and the abductor pollicis brevis. Intramuscular temperature was measured in the deltoid muscle. The results were as follows. 1) The intramuscular temperature in cases of rheumatoid arthritis did not deviate from normal subjects. 2) After the general spring bathing the intramuscular temperature increased about 1℃ and it had no difference between the patients with rheumatoid arthritis and normal subjects. 3) With increasing intramuscular temperature by the general spring bathing in cases of active rheumatoid arthritis the mean potential amplitude decreased and the mean potential duration increased. 4) With increasing intramuscular temperature by the general spring bathing in cases of inactive rheumatiod arthritis the mean amplitude increased and the mean duration decreased. 5) The patterns of potential duration and amplitude before and after a bath on re-examination, one month after a series of the general spring baths, showed a tendency of reverse of the initial patterns. 6) After two months of a series of the general spring baths, the patterns of electromyographic changes of patients with rheumatoid arthritis following the bathing were similar to the initial patterns.
