ABSTRACT
Skeletal muscles undergo both structural and functional changes with puberty. The majority of related studies have focused on changes in the voluntary force generating capacity of differentmuscle groups. Fewer studies have assessed changes in electrically evoked twitch contractile properties of human muscles that occur during puberty. It has been indicated that twitch peak torque (Pt) in postpubertal compared with pre-pubertal children is significantly greater (Belanger and McComas, 1989; Pääsuke et al., 2000). Belanger and McComas (1989) have reported higher post-activation potentiation (PAP) of twitch Pt in pre-compared with post-pubertal children in dorsiflexor muscles, whereas these authors and our previous study (Pääsuke et al., 2000) indicated no significant differences in PAP between these children in plantarflexor (PF) muscles. Davies (1985) reported that in 14-year-old boys the twitch contraction (CT) and half-relaxation (HRT) time of the PF muscles have been shown to be shorter compared with 11-year-old boys, whereas Belanger and McComas (1989) have reported a prolongation of twitch CT and HRT of the dorsiflexor muscles in post-pubertal compared with pre-pubertal boys. Our previous study indicated no differences in twitch CT and HRT in pre-and post-pubertal boys (Pääsuke et al., 2000). Thus, the question of changes in twitch contraction characteristics and PAP with puberty is not yet clear.
