YANAI, Toshimasa

J-GLOBAL         Last updated: Oct 10, 2019 at 02:56
YANAI, Toshimasa
Waseda University
Faculty of Sport Sciences School of Sport and Sciences
Job title
Doctor of Philosophy(University of Iowa)
Research funding number

Research Interests


Research Areas


Academic & Professional Experience

Aug 1991
May 1996
University of Iowa
May 1996
Jul 1996
Lecturer, University of Iowa
Feb 1997
Jan 2004
Lecturer, University of Otago
Apr 2004
Aug 2008
Professor, Chukyo University
Sep 2008
Professor, Waseda University


Athletic Training / Sports Medicine, Indiana University, Bloomington School of HPER
Exercise Science, University of Iowa, Graduate School
Physical Education, Faculty of Physical Education, Chukyo University

Awards & Honors

Jul 1998
The New Investigator's Award, International Society of Biomechanics in Sports

Published Papers

Yanai, Toshimasa; Yanai, Toshimasa; Matsuo, Akifumi; Maeda, Akira; Nakamoto, Hiroki; Mizutani, Mirai; Kanehisa, Hiroaki; Fukunaga, Tetsuo
Journal of Applied Biomechanics   33(4) 305-310   Aug 2017
© 2017 Human Kinetics, Inc. We developed a force measurement system in a soil-filled mound for measuring ground reaction forces (GRFs) acting on baseball pitchers and examined the reliability and validity of kinetic and kinematic parameters determ...
Yanai, Toshimasa;Matsuo, Akifumi;Maeda, Akira;Nakamoto, Hiroki;Mizutani, Mirai;Kanehisa, Hiroaki;Fukunaga, Tetsuo
Mechanical factors determining the rolling speed in baseball batting
Yanaka Takuya;Konda Shoji;Yanai Toshimasa
Taiikugaku kenkyu (Japan Journal of Physical Education, Health and Sport Sciences)   33-48   2017
 A wide range of topspin rotation of a bat around the long-axis, referred to as “rolling”, has been observed in baseball batting, but the mechanical reasons for the large variability among individual batters has not been examined. The ...
Nagami, Tomoyuki; Higuchi, Takatoshi; Higuchi, Takatoshi; Nakata, Hiroki; Nakata, Hiroki; Yanai, Toshimasa; Kanosue, Kazuyuki
Journal of Applied Biomechanics   32(2) 196-204   Apr 2016
© 2016 Human Kinetics, Inc. Although the lift force (F L ) on a spinning baseball has been analyzed in previous studies, no study has analyzed such forces over a wide variety of spins. The purpose of this study was to describe the relationship bet...
Du, Tanghuizi; Narita, Ikumi; Yanai, Toshimasa
Journal of Applied Biomechanics   32(1) 50-58   Feb 2016
© 2016 Human Kinetics, Inc. Low back pain is a common problem among competitive swimmers, and repeated torso hyperextension is claimed to be an etiological factor. The purpose of this study was to describe the three-dimensional torso configuration...

Research Grants & Projects

Coefficient of restitution of a baseball bat is not a set quantity, but it is altered as angular and translational swing velocities and the point of impact are changed
Project Year: Apr 2014 - Mar 2017
This study revealed that even with the same bat head velocity during a swing, varying combinations of angular swing velocity and translational swing velocity can result in different batted ball velocities, and that a large translational swing velo...
Analysis of swimming techniques with an accurate reconstruction of body surface dimensions
Project Year: Apr 2014 - Mar 2017
The purposes of this study were to develop a method for reconstructing the body surface dimensions of human body in motion, particularly during the performance of swimming, and to determine the influence of adopting different breathing techniques ...
Mechanism and adaptability of human movement performance approached with in vivo measurement of musculotendinous behavior
Project Year: Apr 2012 - Mar 2015
The purpose of this study was to evaluate the adaptability of muscle-tendon unit functions and reveal the mechanisms during human movements through the measurement of biological data. We disclosed dynamics of the muscle-tendon units and their mech...
Scapulo-humeral rhythm in throwing and swimming: Is it a risk factor of rotator cuff injuries
Project Year: Apr 2011 - Mar 2014
A prospective cohort study was conducted to determine the kinematic risk factor(s) of impingement syndrome that frequently occurs among athletes who participate in over-head sports. The results indicates that 15 out of 63 baseball pitchers and 21 ...
Project Year: 2010 - 2012
We investigated the lumbar and pelvis motion and electromyographical activities of the trunk and peripelvic muscles during several specific motions of sports activities. The results revealed some specific muscular activities to stabilize the lumba...