Variation of Linear and Nonlinear Parameters in the Swim Strokes According to the Level of Expertise

Abstract

The aim was to examine the variation of linear and nonlinear proprieties of the behavior in participants with different levels of swimming expertise among the four swim strokes. Seventy-five swimmers were split into three groups (highly qualified experts, experts and nonexperts) and performed a maximal 25m trial for each of the four competitive swim strokes. A speed-meter cable was attached to the swimmer's hip to measure hip speed; from which speed fluctuation (dv), approximate entropy (ApEn) and fractal dimension (D) variables were derived. Although simple main effects of expertise and swim stroke were obtained for dv and D, no significant interaction of expertise and stroke were found except in ApEn. The ApEn and D were prone to decrease with increasing expertise. As a conclusion, swimming does exhibit nonlinear properties but its magnitude differs according to the swim stroke and level of expertise of the performer.

The changes in fractal dimension after a maximal exertion in swimming

“…Only a couple of papers have reported yet the FD in human swimming. Barbosa et al [6] noted a FD of 1.84 ± 0.08, 1.85 ± 0.09 and 1.89 ± 0.06 at front-crawl for highly-qualified, expert and non-expert swimmers, respectively. In this paper it was concluded that the level of expertise will affect the complexity of the motor system.…”

“…A very recent paper compared the level of complexity of swimming according to level of expertise. It was noted that swimming does exhibit nonlinear properties but its magnitude differs according to the swim stroke and level of expertise of the performer [6]. The FD was higher with large effect sizes in the group of non-experts than in high-tier swimmers (highlyqualified and expert cohort groups).…”

“…The FD was higher with large effect sizes in the group of non-experts than in high-tier swimmers (highlyqualified and expert cohort groups). The FD was 1.84±0.08, 1.85±0.09 and 1.89±0.06 at front-crawl for highly-qualified, expert and non-expert swimmers, respectively [6]. The trials consisted in all-out bouts of 25m not being under the effect of fatigue (i.e.…”

Differences in swimming smoothness between elite and non-elite swimmers

“…Based on previously observed differences in IVV (Barbosa, Goh, Morais, & Costa, 2016;Matsuda et al, 2014;Schnitzler et al, 2010), we hypothesised that the elite swimmers would swim more smoothly than the non-elite swimmers, and thus have a lower jerk cost. We further hypothesised that within a group of (elite or non-elite) swimmers the faster swimmers would show more jerk than the slower swimmers because swimming faster is associated with greater accelerations and decelerations (Leblanc, Seifert, Tourny-Chollet, & Chollet, 2007) and thus greater jerk.…”

The changes in classical and nonlinear parameters after a maximal bout to elicit fatigue in competitive swimming

“…The complexity of the swimming technique also varies depending on the level of expertise. The dv, ApEn and FD decreases with increasing expertise (frontcrawl: 15.11 ≤ dv ≤ 18.40; 0.66 ≤ ApEn ≤ 0.73; 1.84 ≤ FD ≤ 1.89) (Barbosa, Goh, Morais, & Costa, 2017). These two papers only assessed the variations of nonlinear characteristics depending on the swim stroke performed (task constraint) and the competitive level (organismic constraint) of the performer.…”