Research on twins suggests that while genetics play a major role as children approach maturity, environmental factors (nutrition and health) have a stronger influence on limb proportions during the rapid growth phase of early adolescence (ages 6–14).
Several scientific papers and reviews cover this phenomenon: Biological and Growth Pattern Studies leggy teen
A longitudinal study in the Annals of Human Biology found that distal segments (like feet and lower legs) usually reach their peak growth velocity before more proximal segments (like the thigh), contributing to the "leggy" appearance. Factors and Implications Research on twins suggests that while genetics play
Research published in Nature Scientific Reports explains that the adolescent growth spurt is highly standardized, typically peaking when a child reaches 90% of their final adult height . The adolescent growth spurt of boys and girls of the
The adolescent growth spurt of boys and girls of the ... - PubMed
Papers in PMC indicate that youth athletes undergoing rapid lower limb growth may face a higher incidence of growth-related injuries due to these changing proportions.