Correlation of strength, BMI and limb girth to bone mineral density in young adults with different levels of physical activity

Abstract

The aim of the study is to assess the association of strength and body mass index (BMI) to bone mineral density (BMD) in young adults with different levels of physical activity. Total of thirty young adults,, aged 25-30 years were recruited by advertising. Bone specific physical activity questionnaire (BPAQ) was used to measure the physical activity score. BMD of mid shaft tibia and distal radius of dominant limb was taken using ultrasound densitometry. Speed of sound (SOS) was measured for both the sites and Z-score was documented. Concentric quadriceps peak torque of dominant limb was measured in using a kinetech isokinetic dynamometer. Hand grip strength of dominant hand was measured using digital hand grip dynamometer. Bivariate correlation between both BMD sites and normalized quadriceps strength at 60)/sec, hand grip strength, BPAQ score, BMI, wrist circumference and bi-malleolar girth for different age groups were calculated using Pearson’s coefficient of correlation. Physical activity and strength were found to be independent significant predicators of BMD, also BMI was found to be in positive correlation with bone health. Together these results clearly conclude that bone specific physical activity is an important determinant of BMD after and even before the peak bone mass attainment in young adults of different age groups. In the present study, we have only evaluated BMD of the radius and mid shaft tibia. This measure might be biased from the occupation or the amount of physical activity of a particular limb. Considering these facts we suggest that strength can be a good predictor of BMD at the time of peak bone mass attainment but not before that, on the contrary physical activity is significant predictor of BMD irrespective of age

Key words:

bone mass, hand grip strength, body mass index

Full article (PDF)