A cross-sectional survey of upper and lower limb strength in boys and girls during childhood and adolescence

TLDR

Muscular development during childhood and adolescence is less well documented than changes in height and weight. The study measured standing height, body weight, and isometric elbow flexor and quadriceps strength in 267 boys and 284 girls aged 5–17 from private London schools. Strength increased steadily from ages 8–12 and then rose rapidly in boys even after growth slowed, with pre‑adolescent gains linked to body size and post‑pubertal gains likely driven by hormonal effects.

Abstract

SummaryChanges in height and weight during childhood and adolescence are well documented, yet there is comparatively little comprehensive information about muscular development during this time. In a cross-sectional survey standing height, body weight and isometric strength of the elbow flexor and quadriceps muscles have been measured in 267 boys and 284 girls aged from 5 to 17 years. All the children were from private London schools. The mean heights and weights for each age group were between the 50th and 75th centiles for British children. The strength of both muscle groups in the boys and girls rose steadily in each age group from 8 to 12 years, after which there was a rapid increase in strength of both the quadriceps and elbow flexors in boys which continued even when growth in height and body weight had virtually ceased. In the pre-adolescent phase of growth, muscle strength of the elbow flexors and quadriceps increased as a function of height squared and cubed respectively, suggesting that stretch as a result of elongation of the long bones, and for the quadriceps, loading, may be the primary stimuli during this phase. In the post-pubertal phase some other stimulus, such as a direct action of hormones on the muscle, must be responsible for the continued increase in strength in the boys.