Assessment of pubertal maturity in boys, using height and grip strength.

A method is described for the convenient, noninvasive assessment of pubertal maturity in boys, which is intended for use in studies of developmentally related sports injury. Ninety-eight boys were evaluated for Tanner stage, age, height, weight, body mass index, and maximum (right or left hand) and average grip strength. Height and average grip strength were selected by discriminate analysis as independent predictors of maturity. Immature boys (Tanner stages 1-3) fell below average grip strength of 25 kg and were less than 65 inches (165 cm) in height, whereas boys who exceeded both of these measurements were mature (Tanner stage 4 or 5). This method was validated in a second sample of 99 boys with 100% specificity and sensitivities of 93.5% (immature boys) and 81% (mature boys). A subset of mature boys met the height criterion but did not achieve the average grip strength criterion for maturity. We propose the use of height and grip strength as a practical, noninvasive method to classify physical maturity in boys. In addition, we speculate that the subset of boys who are tall, but weak, may be at increased risk for certain types of sports injuries.