This longitudinal study evaluates the role of impact activity in bone accrual in premenarcheal girls. Twenty-eight gymnasts and 20 controls underwent 1-year analysis; fifteen gymnasts and 8 controls underwent 2-year analysis. Bone mineral density (BMD) was measured yearly by dual energy X-ray absorptiometry. For the 1-year analysis, BMD accrual rates were greater in gymnasts than controls at the forearm only (p < .05). For the 2-year analysis, gains in BMD were 1.5 to 1.9 times greater at the forearm, total hip, and femoral neck for gymnasts (p < .05). These findings confirm the positive effect of impact activity on bone accrual in premenarcheal girls.
Gero and Scerpella are with the Department of Orthopedic Surgery, State University of New York, Upstate Medical University, Syracuse, NY. Cole and van der Meulen are with the Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY. Kanaley is with the Department of Exercise Science, Syracuse University, Syracuse, NY.