Bone density in competitive figure skaters

Objectives: To compare the bone mineral density (BMD) of competitive female teenage figure skaters with a history of fracture with the BMD of skaters without fracture and to compare each group to age-matched. nonathletic controls. Design: Retrospective age-matched cohort. Setting: Tertiary care medical center and 3 local skating clubs. Participants: Thirty-six adolescent female competitive skaters (10 with fracture, 26 without fracture) to 22 age-matched controls. Interventions: Not applicable. Main Outcome Measures: BMD was estimated by quantitative ultrasound. Results: Skaters who had suffered stress fractures had BMD values comparable with those of healthy nonathletic controls. However. skaters who had not suffered stress fractures had calcaneal BMD values 15% to 24% greater than either the controls or skaters with fractures. Among the skaters without fracture. there was a 14% to 19% higher calcaneal BMD in skaters who executed triple jumps relative to skaters who performed only double jumps. Furthermore. there was 7% to 11% greater BMD in the landing foot of the skaters relative to the takeoff foot. Conclusions: Stress fractures in adolescent skaters are not caused by low bone mass but may result from excessive forces placed on a normal skeleton. Our findings also support the hypothesis that higher peak forces are applied to the landing foot relative to the takeoff foot.