Bone mineral density, muscle strength and physical activity: A population-based study of 332 subjects aged 15-42 years

• Published in: Acta orthopaedica Vol. 68; no. 2; pp. 97 - 103
• Main Authors: Düppe, Henrik, Gärdsell, Per, Johnell, Olof, Nilsson, Bo E, Ringsberg, Karin
• Format: Journal Article
• Language: English
• Published: England Informa UK Ltd 1997
• Subjects: Absorptiometry, Photon; Adolescent; Adult; Age Distribution; Bone Density; Cross-Sectional Studies; Exercise; Female; Humans; Male; Muscle Contraction; Physical Fitness; Predictive Value of Tests; Sex Characteristics; Sex Distribution; Surveys and Questionnaires; Sweden; Sweden
• ISSN: 1745-3674; 0001-6470; 1745-3682
• DOI: 10.3109/17453679709003988

The aim of this population-based study was to find out whether differences in levels of physical activity have an influence on bone mass quantity and whether quadriceps muscle strength is a reliable determinant of bone mass. Included were 175 men and 157 women, aged 15-42 years. Bone mineral density (BMD) was measured at various sites by dual X-ray absorptiometry (DXA) and single photon absorptiometry (SPA). Muscle strength was assessed using an isokinetic muscle force meter. A questionnaire was used to estimate the level of physical activity. We found a positive correlation between physical activity and BMD for boys at the distal forearm and for girls at the trochanter (age group 15-16 years). Active men (age group 21-42 years) had up to 9% higher BMD levels at the hip than those who were less active. Quadriceps muscle torque was not an independent predictor of BMD. Our data suggest that a higher level of physical activity-within the limits of a "normal life style"- may have a positive effect on BMD in the proximal femur of young adults, which in turn may lessen the subsequent risk of fracture.