Achilles tendon reflex and aging in atomic bomb survivors, Hiroshima

The relationship between the achilles tendon reflex, aging, and radiation was examined with the photomotograph in 2396 atomic bomb survivors and non-survivors. The subjects consisted of a normal control group with 2100 persons aged 18 to 89 and the group with either mild diabetes mellitus (117 persons), disease of nervous and muscular system (100), history of thyroid dysfunction (61) or other diseases (18). The reflex time of the achilles tendon in the normal control group increased significantly with age, and it was more delayed in woman than in man. The mean time from stimulation to 1/2 relaxation in normal subjects was 290 plus or minus 49 msec (average age, 46) in man and 321 plus or minus 49 msec (average age, 46) in woman, and the values were the same as reported in Europe and America. Statistically significant differences were not found between exposure, obesity, and reflex time. No significant difference was found in mean reflex time. No significant difference was found in mean reflex time between normal group and the group with diseases. The reflex time of each group with diseases seemed to increase with age; however, it was not statisticaily significant. Absence of reflex was found mainly inmore » the cases with diabetes mellitus (22.4%), and the frequency was especially high in the advanced aged both of the group with diabetes mellitus and normal group (3.2%). It was more precise and useful to use the time of stimulation to 1/2 relaxation than contraction time and 1/2 relaxation time, when the achilles tendon reflex was applied to aging test. (JA)« less