TOTAL AND REGIONAL BONE MASS IN FEMALE SOCCER PLAYERS

This cross-sectional study investigated bone mass in female athletes p articipating in an impact-loading sport (soccer), and evaluated whethe r any changes in bone mass could be related to the type of weight-bear ing loading and muscle strength. The group of soccer players consisted of 16 second-division female players (age 20.9 +/- 2.2 years) trainin g for about 6 hours/week. The reference group consisted of 13 nonactiv e females (age 25.0 +/- 2.4 years) not participating in any kind of re gular or organized sport activity. The groups were matched according t o weight and height. Areal bone mineral density (BMD) was measured in total body, head, lumbar spine, femoral neck, Ward's triangle, trochan ter, the whole femur and humerus, and in specific sites in femur diaph ysis, distal femur, proximal tibia, and tibia diaphysis using dual X-r ay absorptiometry. Isokinetic concentric peak torque of the quadriceps and hamstring muscles was measured using an isokinetic dynamometer. T he soccer players had significantly (P < 0.05-0.01) higher BMD in the lumbar spine (10.7%), femoral neck (13.7%), Ward's triangle (19.6%), n ondominant femur and humerus (8.2 and 8.0%, respectively), distal femu r (12.6%), and proximal tibia (12.0%) compared with the nonactive wome n. There was no significant difference in muscle strength of the thigh between the two groups. In the nonactive group, muscle strength in th e quadriceps and especially hamstrings, was correlated to BMD of the a djacent bones (whole femur, hip sites) and also to distant sites (hume rus). In the soccer group, there were no correlations between muscle s trength and BMD of the adjacent and distant bones. Soccer playing and training appears to have a beneficial effect on bone mass in young fem ales, and it seems that there is a site-specific skeletal response to the type of loading subjected to each BMD site. Muscle strength in the thigh is not related to bone mass in female soccer players.