Relationships Of Bone Mineral Density And Muscular Performance In College Students

Abstract

The skeletal system is adapted to mechanical loading such as gravity and muscle contraction. The current gold standard to assess the skeletal health is to use the Dual Energy X-ray Absorptiometry (DXA) to measure bone mineral density (BMD), however, the DXA is costly and not portable. Muscular performance assessment, such as grip strength and jump power, are fairly simple and affordable measurements. PURPOSE: To investigate the relationships between BMD and muscular performance in healthy young adults. METHODS: Thirty healthy college-age individuals, ten males (23.7 ± 1.9 years; 171.9 ± 6.7 cm; 81.8 ± 11.4 kg) and twenty females (23.1 ± 1.9 years; 161.8 ± 6.1 cm; 64.9 ± 15.3 kg), volunteered for the study. Scans of total body, lumbar spine, dual femur and dual forearm were obtained by the iDXA by a licensed technician. Muscular performance was assessed by grip strength, single-leg vertical jump, knee extension and flexion. Pearson’s correlations were used to examine the relationships between BMD, muscular performance, and body composition. RESULTS: Radius BMDs were significantly correlated with grip strength at their corresponding side (r = 0.684 on the right and r = 0.744 on the left, p < 0.001 for both). Total hip BMDs and femoral neck BMDs had strong correlations with hamstring peak torque (PT) and jump peak power (PP) at their corresponding side (p < 0.001 for all) but not quadricep PT (Table 1.). We also found strong correlations between all sites BMD and body composition variables: total mass, total bone free lean mass (BFLM), legs BFLM, and arms BFLM (p < 0.05). CONCLUSION: Our results suggest that muscular performance assessments of grip strength, vertical jump and knee extension are potential alternative tools to estimate bone mineral density in young adults. Further study in a large population and all ages are needed for future investigation.Table 1.: Selected Pearson’s Correlation Coefficients (n=30)