Hiroaki Hobara

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While the spring-like leg behavior of legs in mammalian locomotion has been well documented, its neural basis remains ambiguous. The purpose of the present study was to examine leg stiffness control during hopping. Seven male subjects performed in place two-legged hopping at their preferred frequency with two different contact times of the stance phase,(More)
The purpose of the present study was to utilise a spring-mass model to (1) continuously measure vertical stiffness (K(vert)) and leg stiffness (K(leg)) over an entire 400 m sprint, and (2) investigate the relationship between leg spring stiffness (K(vert) and K(vert)) and the performance characteristics of mean forward running velocity (V(forwad)), mean(More)
Understanding stiffness of the lower extremities during human movement may provide important information for developing more effective training methods during sports activities. It has been reported that leg stiffness during submaximal hopping depends primarily on ankle stiffness, but the way stiffness is regulated in maximal hopping is unknown. The goal of(More)
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(More)
  • Hiroaki Hobara, Y Kobayashi, M Mochimaru
  • International journal of sports medicine
  • 2015
The difference in world records set by able-bodied sprinters and amputee sprinters in the men's 100-m sprint is still approximately 1 s (as of 28 March 2014). Theoretically, forward velocity in a 100-m sprint is the product of step frequency and step length. The goal of this study was to examine the hypothesis that differences in the sprint performance of(More)
Understanding the leg and joint stiffness during human movement would provide important information that could be utilized for evaluating sports performance and for injury prevention. In the present study, we examined the determinants of the difference in the leg stiffness between the endurance-trained and power-trained athletes. Seven distance runners and(More)
Carbon fiber running-specific prostheses (RSPs) have allowed individuals with lower extremity amputation (ILEA) to participate in running. It has been established that as running speed increases, leg stiffness (Kleg) remains constant while vertical stiffness (Kvert) increases in able-bodied runners. The Kvert further depends on a combination of the(More)
Identifying the major determinant of leg stiffness during hopping would be helpful in the development of more effective training methods. Despite the fact that overall leg stiffness depends on a combination of the joint stiffness, it is unclear how the major determinants of leg stiffness are influenced by hopping frequency. The purpose of this study was to(More)
The purpose of the present study was to determine how humans adjust leg stiffness over a range of hopping frequencies. Ten male subjects performed in place hopping on two legs, at three frequencies (1.5, 2.2, and 3.0Hz). Leg stiffness, joint stiffness and touchdown joint angles were calculated from kinetic and/or kinematics data. Electromyographic activity(More)
An understanding of lower extremity stiffness is important for evaluation of sports performance and injury prevention. The aim of this study was to investigate whether stiffness regulation during hopping differed between endurance-trained athletes and untrained subjects. Eight endurance-trained athletes and eight untrained subjects performed two-legged(More)