Muscle Power Predicts Adolescent Bone Strength
- 1 October 2015
- journal article
- Published by Ovid Technologies (Wolters Kluwer Health) in Medicine & Science in Sports & Exercise
- Vol. 47 (10), 2201-2206
- https://doi.org/10.1249/mss.0000000000000648
Abstract
Purpose To assess association between lower body muscle power and bone strength as well as the mediating effect of muscle cross-sectional area (MCSA) on that association. Methods Participants (141 males and 162 females) were approximately 17 yr. Muscle power was predicted using vertical jump and the Sayers equation. Using peripheral quantitative computed tomography (pQCT), bone strength indices were obtained at two locations of the tibia, corresponding to primary stressors acting upon each site: bone strength index for compression (BSI) at the distal 4% site; density-weighted polar section modulus strength–strain index (SSIp) and cortical bone area (CoA) at the 66% midshaft site for torsion. Muscle cross-sectional area was measured at the 66% site. Pearson bivariate and partial correlation coefficients were estimated to quantify the strength of the associations among variables. Direct and indirect mediation model effects were estimated, and 95% bootstrap confidence intervals were constructed to test the causal hypothesis. Height and maturity were examined as covariates. Results Pearson correlation coefficients among muscle power, MCSA, and bone strength were statistically significant (P < 0.01) and ranged from r = 0.54 to r = 0.78. After adjustment for covariates, associations were reduced (r = 0.37 to 0.69) (P < 0.01). Mediation models for males for BSI, SSIp, and CoA accounted for 38%, 66%, and 54% of the variance in bone strength, respectively. Models for females for BSI, SSIp, and CoA accounted for 46%, 77%, and 66% of the variance, respectively. Conclusions We found strong and consistent associations as well as direct and indirect pathways, among muscle power, MCSA, and tibia strength. These results support the use of muscle power as a component of health-related fitness in bone health interventions for older adolescents.This publication has 24 references indexed in Scilit:
- Physical Activity in Childhood May Be the Key to Optimizing Lifespan Skeletal HealthExercise and Sport Sciences Reviews, 2012
- Physical activity positively predicts bone architecture and bone strength in adolescent males and femalesActa Paediatrica, 2010
- Beyond Baron and Kenny: Statistical Mediation Analysis in the New MillenniumCommunication Monographs, 2009
- Is Bone's Response to Mechanical Signals Dominated by Muscle Forces?Medicine & Science in Sports & Exercise, 2009
- Physical activity and femoral neck bone strength during childhood: The Iowa Bone Development StudyBone, 2007
- Mediation AnalysisAnnual Review of Psychology, 2007
- Validity of Two Alternative Systems for Measuring Vertical Jump HeightJournal of Strength & Conditioning Research, 2007
- Bone strength and its determinants in pre- and early pubertal boys and girlsBone, 2006
- Bone Mineral Content per Muscle Cross-Sectional Area as an Index of the Functional Muscle-Bone UnitJournal of Bone and Mineral Research, 2002
- Strain magnitude related changes in whole bone architecture in growing ratsBone, 1997