Ryu Nagahara, Elaheh Amini, Kelly Cristina Cesco Marcon, Peng-Wen Chen, Jessica Chua, Jens Eiberger, Nathaniel Jonathan Claridad Futalan, Jamie Lye, Marko Milan Pantovic, Michal Starczewski, Kriyot Sudsa-Ard, Sri Sumartiningsih, Chien-Yen Wang, Tania Beverly William, Tonnie Kasujja, Tariq Ali Gujar
This study investigated the influence of the intention to lean the body forward on spatiotemporal and ground reaction force variables during the acceleration phase of a sprint. Fourteen active adults performed two 50 m sprints (with and without the intention to lean), during which spatiotemporal variables and impulses were obtained using a long force platform system. Effect size (Cohen’s d) was used to examine the differences between the two trials. We found that running speed and net anteroposterior impulse did not change by the intention for all steps. However, step frequency increased in the initial two steps through decreases in support time and flight time by the intention. Moreover, these shorter support and flight times were caused by a decrease in the vertical impulse. The propulsive impulse did not change during the initial part of acceleration phase, but the braking impulse decreased at the first step. This study demonstrates that an intention to lean the body forward leads to a smaller braking impulse and a higher step frequency through shorter support and flight times and a smaller vertical impulse during the initial part of the acceleration phase of a sprint. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.
National Institute of Fitness and Sports in Kanoya, Kanoya, 891-2393, Japan; Center for Sport and Exercise Science, University of Malaya, Kuala Lumpur, 50603, Malaysia; Autonomous Sport Confederation of Guatemala, Guatemala, 33102, Guatemala; Institute of Sports Sciences, University of Taipei in Taiwan, Taipei, 11114, Taiwan; Exercise and Sport Studies, Nanyang Technology University, Singapore, 639798, Singapore; Myanmar Football Federation, Yangon, 11072, Myanmar; Philippine Sports Commission, Manila, 1004, Philippines; National Youth Sports Institute, Singapore, 737913, Singapore; Faculty of Sport and Physical Education, University of Belgrade, Belgrade, 11000, Serbia; Physiology Department, Institute of Sport National Research Institute, Warsaw, 01-982, Poland; Faculty of Allied Health Science, Thammasat University, Phathumthani, 12121, Thailand; Sports Science Department, Semarang State University, Semarang, 50229, Indonesia; Graduate Institute of Sports Coaching Science, Chinese Culture University, Taipei, 11114, Taiwan; Institute of Athletic and Coaching Science, National Taiwan Sport University, Taoyuan, 33301, Taiwan; Global Sport Management, Seoul National University, Seoul, 08826, South Korea; Tsukuba International Academy for Sport Studies, University of Tsukuba, Tsukuba, 305-8574, Japan; Sports Science Department, Otto Von Guericke University Magdeburg, Magdeburg, 39106, Germany
