Jumping rope (JR) is known to enhance Os Calcis Stiffness Index (OCSI) in postpubertal girls; however the effects in prepubescent girls are unknown.
Qualitative Ultrasound (QUS) indices were compared between competitive JRs (N = 19) and normally active (NA, N = 18) girls 9–12 years old.
Heel QUS, height, weight, percent body fat (bioelectrical impedance), and Tanner Sex Stage (self-report) were measured.
JR were significantly younger and had less body fat than NA (p < .01). No other between group differences were found. OCSI was not different between groups even after correcting for fat mass (p > 0.3). Broadband attenuation (BUA) was correlated with Tanner stage (R > .40; p = .01).
QUS of the heel bone is more related to pubertal status than to JR participation in young girls. Prepubertal girls who perform high intensity jumping have similar bone quality measures as normally active girls.
Heumann is with the Department of Kinesiology, Colorado Mesa University, Grand Junction, CO. Swan is with the Exercise and Wellness Program, Arizona State University, Phoenix, AZ.