Authors: T Rantalainen V Linnamo P V Komi H Selänne A Heinonen
Publish Date: 2010/02/27
Volume: 109, Issue: 4, Pages: 651-658
Abstract
The osteogenicity of a given exercise may be estimated by calculating an osteogenic index OI consisting of magnitude and rate of strain Volleyball involves repetitive jumping and requires high power output and thus may be expected to be beneficial to bone and performance The purpose of the present study was to examine if habitual volleyball playing is reflected in OI Ten elderly habitual volleyball players age 699 SD 44 years and ten matched controls volunteered age 697 42 years as subjects Distal tibia d tibial midshaft 50 and femoral neck FN bone characteristics were measured using pQCT and DXA To estimate skeletal rigidity crosssectional area ToA50 and compressive BSId and bending strength indices SSImax50 were calculated Maximal performance was assessed with eccentric ankle plantar flexion isometric leg press and countermovement jump CMJ A fast Fourier transform FFT was calculated from the acceleration of the center of mass during the CMJ Maximal acceleration MAG and mean magnitude frequency MMF were selected to represent the constituents of OI OI was calculated as the sum of the products of magnitudes and corresponding frequencies Volleyball players had 7 larger ToA50 and 37 higher power in CMJ 15 higher MAG and 36 higher OI P ≤ 0047 than the matched controls No difference was observed in leg press plantar flexion or the MMF P ≥ 0646 In conclusion habitual volleyball players may be differentiated from their matched peers by their dynamic jumping performance and the differences are reflected in the magnitude but not rate of loadingThe study was funded by the Academy of Finland and in part by the TBGS National Graduate School of Musculoskeletal Disorders and Biomaterials The authors wish to express their gratitude to the male choir Sirkat and senior volleyball club Homenokat for their valuable help in subject recruitment
Keywords: