An assessment of maturity from anthropometric measurements
Sex-specific equations from height, sitting height, leg length and age predict years from peak height velocity (maturity offset) with R2 0.92 in boys and 0.91 in girls; the authors advise using the offset as a category, not a continuous value
Among children of one chronological age, somatic and biological maturity differs a lot, most of all around the adolescent growth spurt, so assessing maturity matters both in research and when stratifying youth sport. The authors built a practical, noninvasive way to predict years from peak height velocity (the maturity offset) from anthropometric measures, developing it in one sample and cross-validating it in two others. Abstract only was read.
Participants
Development sample: n=152 Canadian children aged 8-16 yr (79 boys; 73 girls) followed through adolescence from 1991 to 1997 (abstract).
Verification samples: Canadian (measured 1964-1973; 71 boys, 40 girls) and Flemish (measured 1985-1999; 48 girls, 50 boys) children (abstract).
Protocol
Gender-specific multiple regression equations including three somatic dimensions (height, sitting height and leg length), chronological age, and their interactions (abstract).
Equations cross-validated on the combined Canadian and Flemish verification samples (abstract).
Key Results
Coefficient of determination: R2 0.92 for the boys' model and 0.91 for the girls' model; the SEEs were 0.49 and 0.50 respectively (abstract).
In the verification samples, predicted and actual maturity offset differed on average by 0.24 (SD 0.65) yr for boys and 0.001 (SD 0.68) yr for girls (abstract).
The cross-validation passes statistical standards for acceptance, but implementation calls for caution, and maturity offset is better treated as a categorical, not a continuous, assessment (abstract).
The equations are a reliable, noninvasive and practical solution for measuring biological maturity for matching adolescent athletes (abstract).
Practical Application
Can I tell where my teenager is in the growth spurt without an X-ray? The maturity offset equations (Mirwald 2002, B, validation in Canadian and Flemish children) estimate years from peak height velocity from height, sitting height, leg length and age, with R2 0.92 (boys) and 0.91 (girls) — but the authors advise reading the result as a category (before, around, after the spurt), not a precise date.
Inference, not tested here: with between-person SDs of about two-thirds of a year in the verification samples, a single child's estimate can be off by a year or more, which is why the category reading matters.
Not from this paper; the base's own practice: the assistant does not compute maturity offset for a minor; it suggests a club coach or clinician measure it if timing matters.
Limitations
Developed and validated in general-population Canadian and Flemish children, partly measured decades ago; not validated in athletes or cyclists in this paper.
Individual prediction error is substantial (SDs 0.65 and 0.68 yr around the mean difference); the authors themselves recommend categorical use.
The abstract does not report how accuracy varies with age or distance from PHV; full text not read.
How this entry was checked and changed
Why this level
test validation study (rubric B)