Bone mass, muscle strength, and different body constitutional parameters in adolescent boys with a low or moderate exercise level.

This study was conducted to evaluate the association between muscle strength of the thigh, different body constitutional parameters, and bone mineral density (BMD) in adolescents. The subjects were 26 healthy adolescent boys, age 15.9 +/- 0.3 years, not training for more than 3 h per week. BMD was measured in total body, head, humerus, spine, femur, and tibia/fibula. Univariate correlations were measured between the explanatory parameters height, weight, body mass index (BMI), fat mass, lean body mass, quadriceps strength, hamstrings strength, and each BMD site using Pearson's coefficient of correlation. The explanatory variables were also used in a multivariate analysis to explain each BMD site. There was a high degree of concordance when comparing the two methods of analysis. Using the multivariate analysis, quadriceps strength and lean body mass showed significant independent correlations to all BMD sites measured, the correlations being stronger for the adjacent femur and tibia/fibula than for the distant humerus and head. Hamstrings strength correlated significantly and independently with tibia/fibula BMD and spine BMD. Fat mass, BMI, and weight correlated significantly and independently to all BMD sites except femur. This study demonstrates a general relationship between BMD and different body constitutional parameters and muscle strength of the thigh.(ABSTRACT TRUNCATED AT 250 WORDS)