Using Wavelet Transform for Speed Fluctuation Analysis During Manikin Carry with Fins

The Open Sports Sciences Journal 29 December 2017 RESEARCH ARTICLE DOI: 10.2174/1875399X01710010272



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.

Keywords: Fatigue, Fin type, Lifesaving, Speed variation, Sprint, Wavelet transform.
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