Academic Journal
Ratio of forces during sprint acceleration:a comparison of different calculation methods
| العنوان: | Ratio of forces during sprint acceleration:a comparison of different calculation methods |
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| المؤلفون: | Bezodis, Neil E., Colyer, Steffi, Nagahara, Ryu, Bayne, Helen, Bezodis, Ian, Morin, Jean-Benoit, Murata, M, Samozino, Pierre |
| المصدر: | Bezodis , N E , Colyer , S , Nagahara , R , Bayne , H , Bezodis , I , Morin , J-B , Murata , M & Samozino , P 2021 , ' Ratio of forces during sprint acceleration : a comparison of different calculation methods ' , Journal of Biomechanics . https://doi.org/10.1016/j.jbiomech.2021.110685 |
| سنة النشر: | 2021 |
| الوصف: | The orientation of the ground reaction force (GRF) vector is a key determinant of human sprint acceleration performance and has been described using ratio of forces (RF) which quantifies the ratio of the antero-posterior component to the resultant GRF. Different methods have previously been used to calculate step-averaged RF, and this study therefore aimed to compare the effects of three calculation methods on two key “technical” ability measures: decline in ratio of forces (DRF) and theoretical maximal RF at null velocity (RF0). Twenty-four male sprinters completed maximal effort 60 m sprints from block and standing starts on a fully instrumented track (force platforms in series). RF-horizontal velocity profiles were determined from the measured GRFs over the entire acceleration phase using three different calculation methods for obtaining an RF value for each step: A) the mean of instantaneous RF during stance, B) the step-averaged antero-posterior component divided by the step-averaged resultant GRF, C) the step-averaged antero-posterior component divided by the resultant of the step-averaged antero-posterior and vertical components. Method A led to significantly greater RF0 and shallower DRF slopes than Methods B and C. These differences were very large (Effect size Cohen’s d = 2.06 – 4.04) and varied between individuals due to differences in the GRF profiles, particularly during late stance as the acceleration phase progressed. Method B provides RF values which most closely approximate the mechanical reality of step averaged accelerations progressively approaching zero and it is recommended for future analyses although it should be considered a ratio of impulses. |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | application/pdf |
| اللغة: | English |
| DOI: | 10.1016/j.jbiomech.2021.110685 |
| الاتاحة: | https://researchportal.bath.ac.uk/en/publications/57c8c574-8e89-4055-a16e-10e380a585bf https://doi.org/10.1016/j.jbiomech.2021.110685 https://purehost.bath.ac.uk/ws/files/222184640/RF_technical_note_PURE.pdf |
| Rights: | info:eu-repo/semantics/openAccess |
| رقم الانضمام: | edsbas.3537B693 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1016/j.jbiomech.2021.110685 |
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