Using Wavelet Transform for Speed Fluctuation Analysis During Manikin Carry with Fins
Susana Soares1, 2, *, A. Toubekis3, L.M. Machado1, 2, J.P Vilas-Boas1, 2, R.J. Fernandes1, 2, J.A. Abraldes1, 4
Identifiers and Pagination:Year: 2017
Issue: Suppl-2, M8
First Page: 272
Last Page: 278
Publisher Id: TOSSJ-10-272
Article History:Received Date: 19/07/2016
Revision Received Date: 28/07/2017
Acceptance Date: 14/09/2017
Electronic publication date: 29/12/2017
Collection year: 2017
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Wavelet analysis has been used to locate speed variation changes in swimmers, but this elaborated technique was not so far tested in lifesavers carrying a manikin and using one upper limb and fins for propulsion.
Our purpose was to examine the feasibility of using the wavelet analysis to locate time-points of speed variation changes in a manikin carry lifesaving race using stiff and fiber fins.
Fourteen male lifesavers with a mean age of 20.79±4.93 years performed two 25 m all-out manikin carry swimming races using one upper limb and stiff or fiber fins for propulsion. Speed was recorded with a speedometer and its variation was analysed using a wavelet transform analysis. Video recordings were used to measure stroke rate and stroke length within each race.
Wavelet analysis detected, for some lifesavers, one (stiff: 10.50±1.29 vs. fiber: 9.75±0.50 s; p>0.05) and, for other lifesavers, two time-points (stiff: 6.75±0.96 and 11.50±1.29; fiber: 7.00±1.41 and 12.00±1.83 s; p>0.05) of speed variation changes. Mean speed was no different with fin types (stiff: 1.38±0.06 vs. fiber: 1.42±0.09 m∙s-1; p>0.05), as well as average, maximum and minimum speed. Stroke rate, stroke length and stroke index did not change within each race.
Wavelet analysis was effective in detecting one and two time-points of speed variation changes within a short duration manikin carry race independently of the type of fins used. Fiber and stiff fins showed similar biomechanical and speed variations within race changes.