8—17岁儿童少年股外肌肌纤维组成最大等长伸膝力量、相对肌力及肌围的研究

本文用活检一组化方法对153名8～17岁儿童少年(男80人,女73人)做了股外肌快肌纤维%(FT%)的研究,并同时测定了最大等长伸膝力量(MVC)、相对肌力(RMVC)及肌围(活检处腿围,C)。实验发现男、女儿童及全体FT%均呈近似常态分布。且性别间也无显著差异(P>0.05)。还发现8～17岁儿童少年的MVC、RMVC及C均随年龄增长而增大。肌力(MVC及RMVC)与股外肌FT%间只有低度相关(r=0.23,r=0.30;P<0.05),而肌力(MVC)与肌围间却有密切相关(r=0.69,P<0.01)。

MUSCLE FIBER COMPOSITION, MAXIMUM ISOMETRIC KNEE EXTENSION FORCE, RELATIVE MUSCLE FORCE AND LEG CIRCUMFERENCE OF VASTUS LATERAL MUSCLE OF CHILDREN AGED 8-17

Useing the biopsy-histochemical method, FT% of vastus lateral muscle of 153 subjects aged from 8-17(80 boys, 73 girls) was examined. Maximum isometric knee extension force (MVC), relative muscle force (RMVC) and leg circumference (C, circumference at the biopsy position) were also measured. No significant differences were found between FT% of groups of different ages and different sexes (P>0.05), except the group of 17yrs. The mean FT% for boys was 53.6%, for girls 54.0%, and for thetotal 53.8% (P>0.05). The value of FT% were nearly normal distributed. MVC, RMVC and C of boys and girls aged from 8-17 increased by ages. A lower relations were foundbetween the values of MVC, RMVC and the FT% of vastus lateral muscle (r=0.23, r=0.30, P<0.05).However, the values of MVC was closely related to C (r=0.69, P<0.01). It is indicated that the gradualincreases of muscle force mainly depends on the growth of muscle, and is less influenced by the compositionof muscle fiber.