Int J Sports Med 2012; 33(04): 310-313
DOI: 10.1055/s-0031-1291232
Orthopedics & Biomechanics
© Georg Thieme Verlag KG Stuttgart · New York

Step Frequency and Lower Extremity Loading During Running

H. Hobara
1   Research Institute, National Rehabilitation Center for Persons with Disabilities, Department of Rehabilitation for the ­Movement Functions, Tokorozawa, Japan
,
T. Sato
2   Graduate School of Sport Sciences, Waseda University, Tokorozawa, Japan
,
M. Sakaguchi
2   Graduate School of Sport Sciences, Waseda University, Tokorozawa, Japan
,
T. Sato
3   Faculty of Human Life Sciences, Jissen Women’s University, Hino, Japan
,
K. Nakazawa
4   Graduate School of Arts and Sciences, The University of Tokyo, Japan
› Author Affiliations
Further Information

Publication History



accepted after revision 14 September 2011

Publication Date:
01 March 2012 (online)

Abstract

The purpose of the present study was to ascertain whether increase in step frequency at a given velocity during running reduces the lower extremity loading variables, which is associated with tibial stress fracture in runner. We hypothesized that the lower extremity loading variables at a given speed would be minimized at around  + 15% f step. 10 male subjects were asked to run at 2.5 m/s on a treadmill-mounted force platform. 5 step frequencies were controlled using a metronome: the preferred, below preferred ( − 15 and  − 30%) and above preferred ( + 15 and  + 30%). From the vertical ground reaction force, we measured following lower extremity loading variables; vertical impact peak (VIP), vertical instantaneous loading rate (VILR) and vertical average loading rate (VALR). We found that there were significant differences in lower extremity loading variables among 5 step frequency conditions. Furthermore, quadratic regression analyses revealed that the minimum loading variable frequencies were 17.25, 17.55, and 18.07% of preferred step frequency for VIP, VILR and VIAR, respectively. Thus, adopting a step frequency greater than one’s preferred may be practical in reducing the risk of developing a tibial stress fracture by decreasing lower extremity loading variables.