Nonlinear parameters and variability in competitive swimming

41 p.Background: Linear parameters such as swimming kinematics have been the main method of assessing and characterizing competitive swimming strokes. New tools such as approximate entropy (ApEn) and fractal analysis can be a useful approach. The aim is to find out if there are significant differences between the strokes in the nonlinear parameters. Hypothesis: It is hypothesized that there will be significant difference between the 4 strokes in terms of their fractal properties and approximate entropy. Method: 29 healthy competitive swimmers (Mean age= 14.8 ± 1.4 years, Mass = 56.37 ± 8.9kg, Height= 1.65 ± 0.08m) with at least 4 years of swimming experience and participating on regular basis in at least national level competitions participated in this studying. Participants performed 4 x 25m swim with different strokes for each set, namely front crawl(FR), breast stroke(BR), backstroke(BS) and butterfly stroke(FLY), at maximal effort. Kinematic data will be collected using the Swim Speedo-meter. Results: Results shown that there are significant differences (p<0.05) in the ApEn aspect between the 4 strokes. For fractal analysis, post-hoc test shown that breast stroke is significantly different (p