A longitudinal study of bone area, content, density, and strength development at the radius and tibia in children 4-12 years of age exposed to recreational gymnastics

A Summary This study investigated the long-term relationship between the exposure to childhood recreational gymnastics and bone measures and bone strength parameters at the radius and tibia. It was observed that individuals exposed to recreational gymnastics had significantly greater total bone content and area at the distal radius. No differences were observed at the tibia. Introduction This study investigated the relationship between exposure to early childhood recreational gymnastics with bone measures and bone strength development at the radius and tibia. Methods One hundred twenty seven children (59 male, 68 female) involved in either recreational gymnastics (gymnasts) or other recreational sports (non-gymnasts) between 4 and 6 years of age were recruited. Peripheral quantitative computed tomography (pQCT) scans of their distal and shaft sites of the forearm and leg were obtained over 3 years, covering the ages of 4-12 years at study completion. Multilevel random effects models were constructed to assess differences in the development of bone measures and bone strength measures between those exposed and not exposed to gymnastics while controlling for age, limb length, weight, physical activity, muscle area, sex, and hours of training. Results Once age, limb length, weight, muscle area, physical activity, sex, and hours of training effects were controlled, it was observed that individuals exposed to recreational gymnastics had significantly greater total bone area (18.0 +/- 7.5 mm(2)) and total bone content (6.0 +/- 3.0 mg/mm) at the distal radius (p < 0.05). This represents an 8-21 % benefit in ToA and 8-15 % benefit to ToC from 4 to 12 years of age. Exposure to recreational gymnastics had no significant effect on bone measures at the radius shaft or at the tibia (p > 0.05). Conclusions Exposure to early life recreational gymnastics provides skeletal benefits to distal radius bone content and area. Thus, childhood recreational gymnastics exposure may be advantageous to bone development at the wrist.