Santiago Veiga

Comparison of starts and turns of national and regional level swimmers by individualized-distance measurements

The aim of this study was to compare the race characteristics of the start and turn segments of national and regional level swimmers. In the study, 100 and 200-m events were analysed during the finals session of the Open Comunidad de Madrid (Spain) tournament. The “individualized-distance” method with two-dimensional direct linear transformation algorithm was used to perform race analyses. National level swimmers obtained faster velocities in all race segments and stroke comparisons, although significant inter-level differences in start velocity were only obtained in half (8 out of 16) of the analysed events. Higher level swimmers also travelled for longer start and turn distances but only in the race segments where the gain of speed was high. This was observed in the turn segments, in the backstroke and butterfly strokes and during the 200-m breaststroke event, but not in any of the freestyle events. Time improvements due to the appropriate extension of the underwater subsections appeared to be critical for the end race result and should be carefully evaluated by the “individualized-distance” method.

Effects of different swimming race constraints on turning movements

The aim of this study was to investigate the effects of different swimming race constraints on the evolution of turn parameters. One hundred and fifty-eight national and regional level 200-m (meters) male swimming performances were video-analyzed using the individualized-distance model in the Open Comunidad de Madrid tournament. Turn (p<.001, ES=0.36) and underwater distances (p<.001, ES=0.38) as well as turn velocity (p<.001, ES=0.69) significantly dropped throughout the race, although stroke velocity and underwater velocity were maintained in the last lap of the race (p>.05). Higher expertise swimmers obtained faster average velocities and longer distances in all the turn phases (p<.001, ES=0.59), except the approach distance. In addition, national level swimmers showed the ability to maintain most of the turn parameters throughout the race, which assisted them in improving average velocity at the end of races. Therefore, the variations in the turning movements of a swimming race were expertise-related and focused on optimizing average velocity. Turning skills should be included in the swimming race action plan.

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

Abstract The aim of this study was to develop a new application based on the “individual distances” method to analyse swimming races, and to compare it with the traditional “fixed distances” method. One hundred and seventy-nine national level 100 m (four strokes) performances obtained from the 2008 “Open Comunidad de Madrid” (Spain) were analysed using a two-dimensional Direct Linear Transformation (2D-DLT) video analysis system. Average velocities in all race segments (P < 0.001) were faster using the “individual distances” method than when employing the “fixed distances” method. Specifically, start and turn times were shorter (P < 0.001) while free swimming times were longer (P < 0.001) when using the “individual distances” method. Correlations between methods were moderate to high, but several gender and stroke groups showed poor to no correlation, especially during the start and turn segments. Differences between methods were higher in some groups (female swimmers and freestyle stroke) where the start and turn distances were shorter. Measurements with the 2D-DLT technique provide distances and times employed during the race segments, which do not completely agree with times at fixed distances. Therefore, when evaluating swimming races, a combination of the individual and fixed distances methods should be used.

Underwater and surface strategies of 200 m world level swimmers

Abstract Pacing strategies of elite swimmers have been consistently characterised from the average lap velocities. In the present study, we examined the racing strategies of 200 m world class-level swimmers with regard to their underwater and surface lap components. The finals and semi-finals of the 200 m races at the 2013 World Swimming Championships (Barcelona, Spain) were analysed by an innovative image-processing system (InThePool® 2.0). Free swimming velocities of elite swimmers typically decreased throughout the 200 m race laps (−0.12 m · s–1, 95% CI −0.11 to −0.14 m · s–1, P = 0.001, η2 = 0.81), whereas underwater velocities, which were faster than free swimming, were not meaningfully affected by the race progress (0.02 m · s–1, −0.01 to 0.04 m · s–1, P = 0.01, η2 = 0.04). When swimming underwater, elite swimmers typically travelled less distance (−0.66 m, −0.83 to −0.49 m, P = 0.001, η2 = 0.34) from the first to the third turn of the race, although underwater distances were maintained on the backstroke and butterfly races. These strategies allowed swimmers to maintain their average velocity in the last lap despite a decrease in the free swimming velocity. Elite coaches and swimmers are advised to model their racing strategies by considering both underwater and surface race components.

Effect of the starting and turning performances on the subsequent swimming parameters of elite swimmers

Abstract In the present research, we examined the effect of the starting and turning performances on the subsequent swimming parameters by (1) comparing the starting and turning velocities with the swimming parameters on the emersion and mid-pool segments and (2) by relating the individual behaviour of swimmers during the start and turns with subsequent behaviour on each swimming lap. One hundred and twelve 100 m performances on the FINA 2013 World Swimming Championships were analysed by an image-processing system (InThePool 2.0®). At the point of the start emersion, the swimming parameters of the 100-m elite swimmers were substantially greater than the mid-pool parameters, except on the breaststroke races. On the other hand, no diminution in the swimming parameters was observed between the turn emersion and the mid-pool swimming, except on the butterfly and backstroke male races. Changes on the surface swimming kinematics were not generally related to the starting or turning parameters, although male swimmers who develop faster starts seem to achieve faster velocities at emersion. Race analysts should be aware of a transfer of momentum when swimmers emerge from underwater with implications on the subsequent swimming kinematics, especially for male swimmers who employ underwater undulatory techniques.

Do faster swimmers spend longer underwater than slower swimmers at World Championships

Abstract The main objectives of the present research were (1) to examine the relationships between the distances travelled underwater during the start and turn segments with swimming race performance at the elite level and (2) to determine if the individualised-distance start and turn parameters affect the overall race performance. The race parameters of the 100 and 200 m events during 2013 World Championships were measured by an innovative image-processing system (InThePool® 2.0). Overall, 100 m race times were largely related to faster start velocities in mens breaststroke and freestyle events. Conversely, overall, 200 m race times were largely related to longer starting distances in the womens butterfly events, to longer turn distances in mens and womens backstroke and womens butterfly events and to shorter turn distances in womens freestyle events. Changes on the start or turn velocities could represent moderate time improvements in most of the 100 m events, whereas modifications on the start or turn distances (especially in the last turn) could provide elite swimmers with time improvements of practical importance on the 200 m events. The evaluation of races by individualised-distance parameters should be provided to elite swimmers in order to decide the most appropriate race segment configuration for each event.

Effect of functional classification on the swimming race segments during the 2012 London Paralympic Games

Abstract The aims of the present research were (1) to characterise the individualised race segments configuration (start, turn and free swimming) of Paralympic swimmers and (2) to examine the influence of the swimmers’ functional classification on their race segments configuration. Finalists (248 men and 264 women) in the 100 m swimming events of the 2012 London Paralympic Games were distributed in five different subgroups based on their functional class designation and race performances were video-analysed with 2D-DLT algorithms. The start and turn distances of Paralympic swimmers in the 100 m events did not coincide with the traditional 10–15 m segments and they depended on the swimmer’s functional group (η2 = 0.48), as longer start and turn distances were observed according to the lower degree of impairment of swimmers. However, no differences were observed in the start and turn distances of the least physically impaired, the visually and the intellectually impaired swimmers (S8–S14), regardless of the stroke and gender. These results indicate that, in terms of the race segments configuration, there is no evidence to support the classification of S8–S14 swimmers in different functional classes.

A PREVIOUS HAMSTRING INJURY AFFECTS THE KICKING TECHNIQUE AND THIS IS INFLUENCED BY GENDER AND LIMB DOMINANCE

Background Although the hamstring muscle group gets loaded during the kicking motion, the effect of a previous hamstring injury on the kicking skill has not been studied in detail. Objective To the study the effect of a previous hamstring injury on the kicking technique, and how gender and limb dominance influences the same. Design Observational study. Participants were required to kick the ball into a target 7 m away using a four step run-up. Five valid kicks were taken from the dominant and non-dominant limb each. Setting Laboratory conditions on FIFA approved artificial turf, with a three-dimensional Vicon motion capture system at 200Hz and a Kistler force platform at 1000Hz. with participants belonging to Spanish First (women) and Second (men) Division teams. Participants 45 professional soccer players (females=26, males=19) who belonged to clubs that had the same number of training sessions and matches per week. Main Outcome Measurements Ball velocities, kinematic and kinetic data for the hip and knee of the kicking leg in the sagittal plane, and the reaction forces for the ground and the support leg. 3-way ANOVA was used to compare the data. Results Previously injured female athletes had a lower peak hip velocity in the dominant limb kicks; and a smaller knee flexion angle, and a lower hip flexion velocity in the non-dominant limb kicks. Conclusions Kicking technique is affected by a previous hamstring injury in females especially in phases where the hamstring muscles are the most active. Differences in male soccer players were not seen. Thus these injuries must be treated differently in male and female soccer players, and whether the injury occurred in the dominant or non-dominant limb. An additional study with a greater number of previously injured athletes would be necessary to provide conclusive results.