Affiliations 

  • 1 National Institute of Fitness and Sports in Kanoya, Kanoya 891-2393, Japan. nagahara@nifs-k.ac.jp
  • 2 Center for Sport and Exercise Science, University of Malaya, Kuala Lumpur 50603, Malaysia. elaheham@yahoo.com
  • 3 Autonomous Sport Confederation of Guatemala, Guatemala 33102, Guatemala. kel.marcon@gmail.com
  • 4 Institute of Sports Sciences, University of Taipei in Taiwan, Taipei 11114, Taiwan. a0928438940@gmail.com
  • 5 Exercise and Sport Studies, Nanyang Technology University, Singapore 639798, Singapore. jessica.chua@swimming.org.sg
  • 6 Myanmar Football Federation, Yangon 11072, Myanmar. jens-eiberger@web.de
  • 7 Philippine Sports Commission, Manila 1004, Philippine. n_futalan@yahoo.com
  • 8 National Youth Sports Institute, Singapore 737913, Singapore. jamie_lye@nysi.org.sg
  • 9 Faculty of Sport and Physical Education, University of Belgrade, 11000 Belgrade, Serbia. marko.sportscience@gmail.com
  • 10 Physiology Department, Institute of Sport National Research Institute, 01-982 Warsaw, Poland. michalstarczewski1@gmail.com
  • 11 Faculty of Allied Health Science, Thammasat University, Phathumthani 12121, Thailand. kriyot.s@allied.tu.ac.th
  • 12 Sports Science Department, Semarang State University, Semarang 50229, Indonesia. sri.sumartiningsih@gmail.com
  • 13 Institute of Athletic and Coaching Science, National Taiwan Sport University, Taoyuan 33301, Taiwan. cirewcirew@gmail.com
  • 14 Global Sport Management, Seoul National University, Seoul 08826, Korea. taniabeverly@yahoo.com
  • 15 Tsukuba International Academy for Sport Studies, University of Tsukuba, Tsukuba 305-8574, Japan. kasujjat@gmail.com
  • 16 Sports Science Department, Otto Von Guericke University Magdeburg, Magdeburg 39106, Germany. t_gujar@yahoo.com
Sports (Basel), 2019 May 31;7(6).
PMID: 31159177 DOI: 10.3390/sports7060133

Abstract

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.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.