Kinematic characteristics of the stroke and orientation of the hand during front crawl resisted swimming

Abstract

The aim of this study was to examine the acute effect of front crawl sprint resisted swimming with different added resistances on the kinematic characteristics of the stroke and the orientation of the hand. Ten female swimmers swam four maximal trials (25 m) with small, moderate, large, and no added resistance respectively. Four camcorders were used to record the underwater motion of the right hand and digitizing was undertaken using the Ariel Performance Analysis System. Stroke rate, the stroke length, and mean swimming velocity were significantly decreased, whereas the total duration of the stroke and the relative duration of the pull and push phases were significantly increased during resisted swimming. The increase in the total duration of the stroke was accompanied by an increase in absolute pull length, while no alterations were observed in relative pull length or medial-lateral displacements of the hand. Moreover, the mean resultant velocity of the hand, as well as the pitch and the sweepback angles of the hand were not modified. In conclusion, resisted swimming appears to be a specific form of training, at least regarding its acute effect, although long-term effects should be investigated further.

Computational Fluid Dynamics Study of Swimmer's Hand Velocity, Orientation, and Shape: Contributions to Hydrodynamics

“…Initial kinematic parameters corresponding to real swimmer's single front crawl underwater stroke cycle were obtained from previous experimental study [13]. The single front crawl stroke cycle is usually divided into four phases: glide—from the entry of the hand into the water to its maximal forward displacement in the longitudinal displacement; pull—from the maximal forward displacement of the hand in the longitudinal displacement (i.e.…”

“…Different values of average velocity correspond to different times (Table 1), resulting in three parts of underwater stroke time from glide phase, three from pull and three from push phases. Gourgoulis et al [13] determined the velocity of the hand as the mean of the resultant velocities of the 2nd and the 5th metacarpophalangeal joints and transformed from the external (O; X, Y, Z) to the local reference system (O; x, y, z) of the swimmer's hand. In CFD calculations, this velocity was used as the resultant average velocity of water flow while the hand model was kept stationary.…”

“…Rouboa et al [11] agree that both the propulsion and drag forces will fluctuate during individual phases of stroke cycle along with the respective variation of angle of attack and sweepback angle. Schleihauf (as cited in [13]) summarised that the ideal pitch angle during the underwater motion of the hand will produce an optimal combination of lift and drag forces, which in turn will generate a resultant force that could be predominantly directed in forward direction. Gardano and Dabnichki [7] noticed that, in addition to the pitch angle having the influence on drag force, at the high Reynolds numbers (which swimmers usually undergo in the competitions), two main factors affect the drag force: shape and arm orientation.…”

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

“…non-propulsive phase) and a longer push (propulsive), reinforced by increases of force impulses and peak push forces. Tethered swimming [88][89][90] is another technique to manipulate the swimmers' environment: individuals are attached to the pool wall by a non-extensible cable and must maintain their swimming position [88]. 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].…”

“…Tethered swimming [88][89][90] is another technique to manipulate the swimmers' environment: individuals are attached to the pool wall by a non-extensible cable and must maintain their swimming position [88]. 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.…”