Kinematic analysis of butterfly turns of international and national swimmers

Abstract

The aims of this study were (1) to evaluate the different turn phases of 200 m butterfly during competition in a 50 m pool, (2) to determine if wall contact times are related to swim speed and (3) to compare the turn variables of a European Champion with other swimmers. In the first part of the study, we assessed the turns of 22 swimmers ranked in three groups according to 200 m butterfly swim performance (fast group = 121.73+/-3.03 s, intermediate group = 126.25+/-0.55 s, slow group = 129.24+/-2.30 s). Two turn times were recorded: the first before the turn (i.e. the time it takes the swimmer's head to reach the wall from 7.5 m away) and the second after the turn (i.e. the time from the wall to the point at which the swimmer's head passes 7.5 m away). The third turn was performed significantly faster by the fast group than by the slow group, both before (P< 0.01) and after (P< 0.02) the turn. In the second part of the study, objectives (2) and (3) were evaluated among 15 swimmers based on a specific protocol. Three cameras (50 Hz) simultaneously recorded the turn; these were placed above the water 10 m before the wall, 5 m before and just above the wall. Longer contact times of the feet on the wall were associated with a faster push-off speed (P < 0. 02). The European Champion achieved an improved contact time while performing a rapid pull-out speed.

A new procedure for race analysis in swimming based on individual distance measurements

“…These data are considerably different than the estimated 30% when the start and turn segments are defined as 15 m fixed distances. Thus, even though the estimation of race segments with visual references is widely accepted (Tourny-Chollet et al, 2002), precautions should be taken when solely evaluating performances with fixed distances.…”

“…In the turn segment, recordings with a single camera measured the same fixed distance in and out the turn, in order to avoid perspective errors (Shimadzu et al, 2008). Using this procedure, several stroke cycles are included from the reference mark (usually at 7.5 m) to the wall (Tourny-Chollet et al, 2002). Discrepancy between the two compared methods is even greater in some of the groups (female swimmers and freestyle stroke: Tables II and III), where the start and turn distances are relatively shorter (Table IV).…”

“…To date, the estimation of race segments with fixed distances is widely accepted (Tourny-Chollet, Chollet, Hogie, & Papparodopoulos, 2002) but no previous publications have compared it with true distances covered by the swimmers. When a swimmer emerges before the start or turn reference mark, he covers the distance to the reference mark with swimming strokes.…”

Start and turn performances of elite sprinters at the 2016 European Championships in swimming

“…This is, from the block phase, flight phase and underwater phase. In the turn, the push-off time and peak force on the wall performing the flip turn (Lyttle et al, 1999), and the wall contact time (hands and feet) and a quick pull-out in the open turn (Tourny-Chollet, Chollet, Hogie, & Papparodopoulos, 2002), are the key determinants. A significant and moderate-strong contribution effect (Table 4) was noted for the start and turn parameters.…”

Effects of different swimming race constraints on turning movements

“…Several factors have been reported to affect the effectiveness of underwater undulatory swimming, including the kick frequency (Cohen et al, 2012), amplitude (Houel, Elipot, André, & Hellard, 2013), symmetry (Atkinson et al, 2014) and swimmer morphology (von Loebbecke, Mittal, Fish, et al, 2009). Distances traveled with underwater movements have been found relevant to the starting and turning (Blanksby, Elliott, McElroy, & Simpson, 1998;Tourny-Chollet, Chollet, Hogie, & Papparodopoulos, 2002) competitive performances. However, it is unknown how swimmers organize the underwater or surface components during a swimming race or how various competitive swimming constraints (like the number of laps, gender, expertise or event stroke) could influence the underwater swimming parameters.…”