Distribution of fibre sizes in human skeletal muscle. An enzyme histochemical study in m tibialis anterior

The aim of the study was to determine the distribution, total number and size of different types of fibres in whole cross-sections of female m tibialis anterior and to compare these data with previous results obtained from male skeletal muscles as well as with data on female muscles obtained by biopsy technique. The distribution of fibre types varied within the muscle cross-sections, and the pattern was slightly different from that earlier described for male muscles (Henriksson-Larsén et al. 1983). No difference in mean fibre type occurrence was found between the left and right muscles of the females. The type 2 fibres varied in size in different muscle regions and were usually largest at the deep surface of the muscle. Both the total number and size of the muscle fibres were smaller in the female muscles than in the corresponding male muscles (Henriksson-Larsén et al. 1985a, b). This resulted in a 30-40% smaller value for the total muscle fibre area in the female muscles compared to the male muscles.