Effect of hand paddles and parachute on the index of coordination of competitive crawl-strokers

Abstract

We investigated the effects of hand paddles and parachute on the relative duration of stroke phases and index of coordination of competitive crawl-strokers. Eleven male-swimmers (age: 21.9 ± 4.5 years; 50-m best time: 24.23 ± 0.75 s) were evaluated in four maximal-intensity conditions: without equipment, with hand paddles, with parachute, and with both hand paddles and parachute. Relative stroke phase duration of each arm, swimming velocity, and stroke rate were analysed from video (60 Hz). The index of coordination was quantified based on the lag time between propulsive phases of each arm, which defined the coordination mode as catch-up, opposition or superposition. The stroke rate decreased in all conditions (P < 0.05) and swimming velocity decreased with parachute and with paddles + parachutes (P < 0.05). The coordination mode changed from catch-up in free swimming (-2.3 ± 5.0%) to opposition with paddles (-0.2 ± 3.8%), parachute (0.1 ± 3.1%), and paddles + parachute (0.0 ± 3.2%). Despite these variations, no significant differences were observed in relative duration of right and left arm-stroke phases, or in index of coordination. We conclude that the external resistances analysed do not significantly influence stroke phase organization, but, as a chronic effect, may lead to greater propulsive continuity.

Untitled

“…Results were interpreted from the point of prediction of sport functioning efficiency. Telles, Barbosa, Campos, and Júnior (2011), studying bio-mechanical characteristics of swimmers' movements, confirmed the presence of dependences between movement phases and movements' coordination. It was found that strength of correlation increases under durable loads for fitness improvement.…”

Effect of Different Loads on Stroke and Coordination Parameters During Freestyle Semi-Tethered Swimming

“…Intra-cycle velocity variations were studied at different swimming paces (Schnitzler et al, 2010) and while swimming with parachute (Schnitzler et al, 2011), but not with different loads. To the authors’ knowledge, only one study (Telles et al, 2011) has examined changes in index of coordination (IdC) in three different resisted swimming conditions.…”

Individual–Environment Interactions in Swimming: The Smallest Unit for Analysing the Emergence of Coordination Dynamics in Performance?

“…In these experimental conditions, aquatic resistance is higher than traditionally encountered in free motion, since the parachute creates a bigger frontal area opposed to displacement. In study by Telles et al [86], the increased resistance caused a change in inter-arm coordination (exemplified by a change in the Index of Coordination [44]) from catch-up to opposition mode, or even to a superposition mode {Schnitzler:2011ud}. This superposition mode is usually only exhibited by expert swimmers suggesting that the use of the parachute may help sub-elite swimmers to better coordinate actions againsthigh resistances.…”

“…This induces temporal modifications in the aquatic stroke in comparison to classical swimming conditions: pull and push durations increase, whereas the non-propulsive phase (recovery) decreases, resulting in a global increase in the entire stroke time [88,90]. In both parachute and tethered situations, the resistances' increase was such that any moment without propulsion strongly affected velocity [86], leading to behavioural modifications of the swimming stroke. These adaptations could be to: (i) increase the time spent in propulsive phases, (ii) decrease their frontal projected area, (iii) increase the continuity of their propulsive actions, or (iv), increase the force they developed to progress against the artificial resistances.…”

“…This is typically achieved with swimming paddles [86,[94][95][96] or fins [97,98], both of which are conducive to higher thrust production than traditional swimming conditions. Depending on the body surface exposed to water, new spatiotemporal strategies emerge in swimmers, helping them to move larger masses of inert water: with large paddles, they increase the time needed to complete one stroke cycle by increasing the time spent in the entry, catch and recovery phases of the front crawl [96].…”