Bone Mineral Density and Contet of Collegiate Throwers: Influence of Maximum Strength
AIM: Bone changes in size and density in response to different levels of stress. Alterations to bone mineral density (BMD) appear to occur in a site specific manner. Even though BMD has been examined in many populations there is a paucity of data looking at strength-power athletes, such as throwers. Therefore, the purpose of this study was to examine the BMD of a group of USA Division I collegiate throwers (e.g. shot put, discus, etc.). METHODS: Seven throwers (4 males; 3 females) who were 19.0 ± 0.9 years had their BMD compared to an age matched control group (n=14; 8 women and 6 men) and normative data. BMD was measured with dual X-ray absorptometry. Potential right/left side and sex difference in BMD were also examined. Maximal isometric strength was assessed using a mid-thigh pull while standing on a forceplate which generated force-time curves. Peak force (PF) and normalized peak force (PFa) were then correlated with BMDs. RESULTS: Generally, throwers had denser bones with male throwers tending to have a greater total BMD (P≤0.05). The dominant arm BMD was slightly greater when compared to non-dominant arm (P≤0.05). Furthermore, total body BMD was related to PF (r=0.68, r2 =0.46) and PFa (r=0.56, r2=0.31). CONCLUSIONS: Throwers have greater BMDs than non-athletes and most other athletes. However, throwers only showed a small indication of sidedness. It is likely that the BMDs observed in this study stem from the training intervention (e.g. whole body heavy lifting) undertaken by this population.
Whittington, J. M.; Schoen, E. J.; Labounty, L. L.; Hamdy, R.; Ramsey, Michael W.; Stone, Margaret E.; Sands, William A.; Haff, G. Gregory; and Stone, Michael H.. 2009. Bone Mineral Density and Contet of Collegiate Throwers: Influence of Maximum Strength. Journal of Sports Medicine & Physical Fitness. Vol.49(4). 10. ISSN: 1827-1928