DISTRIBUTION OF FIBER TYPES IN THE MUSCLES OF THE FOREARM IN CHINESE / 解剖学报

ABSTRACT

Samples of skeletal muscle in forearm were taken from 60 sites in each of 10 normal autopsy subjects (male 7, female 3) between 3 and 69 years of age. The distribution and composition of type I and type II fibers in the muscles of the forearm were studied by histochemical method for myofibrillar ATPase. The results showed that the mean percentage of type I fibers ranged between 45% to 59% in the muscles of the forearm. In general, the slow contracting fibers of the forearm muscles were slightly higer than 50%. In the flexors and extensors of the forearm the respective percentage of type I fibers were 49.8% and 55.3%. The slow contraction fibers of the extensors muscle group showed higher proportion of type I fibers than those of the flexor group and the difference is statistically significant (P