ORIGINAL ARTICLE Trabecular bone microarchitecture in female collegiate gymnasts C. M. Modlesky & S. Majumdar & G. A. Dudley Received: 15 March 2007 / Accepted: 1 October 2007 / Published online: 12 December 2007 # International Osteoporosis Foundation and National Osteoporosis Foundation 2007 Abstract Summary Using high-resolution magnetic resonance imag- ing, we observed more developed trabecular bone micro- architecture in the proximal tibia of female collegiate gymnasts vs. matched controls. This suggests that high- load physical activity may have a positive effect on the trabecular microarchitecture in weight-bearing bone. Introduction Participation in physical activities that over- load the skeleton, such as artistic gymnastics, is associated with increased areal bone mineral density (aBMD); how- ever, the status of trabecular microarchitecture in the weight-bearing bone of gymnasts is unknown. Methods Eight female collegiate artistic gymnasts and eight controls matched for age, height, body mass, gender and race were recruited for the study. Apparent trabecular bone volume to total volume (appBV/TV), trabecular number (appTb.N), thickness (appTb.Th) and trabecular separation (appTb.Sp) were determined using high resolution magnet- ic resonance imaging. Areal bone mineral density, bone mineral content (BMC) and bone area in the proximal tibia were determined using dual-energy X-ray absorptiometry. Group differences were determined using t-tests. The magnitude of group differences was expressed using Cohen’ sd(d). Results Gymnasts had higher appBV/TV (13.6%, d =1.22) and appTb.N (8.4%, d =1.45), and lower appTb.Sp (13.7%, d =1.33) than controls (p<0.05). Gymnasts had higher aBMD and BMC in the proximal tibia, although the differences were smaller in magnitude (d =0.75 and 0.74, respectively) and not statistically significant (p>0.05). Conclusion The findings suggest that high-load physical activity, such as performed during gymnastics training, may enhance the trabecular microarchitecture of weight-bearing bone. Keywords Exercise . Gymnastics . Magnetic resonance imaging . Mechanical loading . Physical activity Introduction Physical activity, especially activity that includes high-load movements, is regarded as a powerful environmental determinant of bone mass. This idea is supported by cross-sectional studies demonstrating elevated levels of bone mass in athletes involved in high-load physical activity [1–3] and longitudinal studies demonstrating increases in areal bone mineral density (aBMD) and bone mineral content following jump training [4], weight lifting [5, 6] and artistic gymnastics participation [7, 8]. While physical activity clearly has a positive effect on measures of bone mass, such as aBMD, its effect on trabecular bone microarchitecture is less understood [9]. Trabecular bone microarchitecture is an important skeletal feature that identifies those with fracture as well as, or better than, aBMD [10, 11]. Furthermore, when measures of trabecular Osteoporos Int (2008) 19:1011–1018 DOI 10.1007/s00198-007-0522-x C. M. Modlesky (*) Department of Health, Nutrition and Exercise Sciences, University of Delaware, Newark, DE 19716, USA e-mail: modlesky@udel.edu S. Majumdar Magnetic Resonance Science Center, Department of Radiology, University of California, San Francisco, San Francisco, CA, USA G. A. Dudley Department of Kinesiology, University of Georgia, Athens, GA, USA