Perception and action in swimming: Effects of aquatic environment on upper limb inter-segmental coordination

Influence of stroke rate on coordination and sprint performance in elite male and female swimmers

“…Following the procedures of Dadashi et al, 33 the pull, push, and recovery phases were identified based on the accelerometric and gyroscopic signals from the IMUs positioned at the lower arm and sacral levels. The mediolateral angular velocity of the lower arm was used to detect the hand entry into the water (as previously done by Guignard et al 34 ). This corresponds to the first observable peak in the raw gyroscopic data between the instant of maximum angular velocity (corresponding to the half arm recovery) and the start of the pull.…”

“…The swimmers were equipped with three inertial measurement units (IMUs, Hikob Fox©): one IMU on each forearm and one IMU on the sacrum. Waterproofing, fixation, and calibration procedures were carried out according to Dadashi et al 33 and Guignard et al 34 Each IMU was composed of a three-dimensional accelerometer (±16 G), a three-dimensional gyroscope (±1200/s) and a three-dimensional magnetometer (±8.1 Gauss) and recorded at 100 Hz. The three axes of the IMU were aligned with the swimmer such that the x-, y-, and z-axes corresponded, respectively, to the mediolateral, anteroposterior, and vertical axes.…”

Upper to Lower Limb Coordination Dynamics in Swimming Depending on Swimming Speed and Aquatic Environment Manipulations

“…Although rarely used, a swimming flume can create comparable dynamic environmental constraints. Flumes are constrained channels of moving water that push the upper limbs of the swimmer backwards; through entrainment of air bubbles into the moving volume of water (in an unpredictable manner) a possible influence on both turbulence and buoyancy, challenging the horizontality of the swimmers body, can occur; see Guignard et al (2017). Use of a flume offers the possibility to (i) apply a constraint that may directly impact the success of the task (swimmers are able/not able to sustain position in the moving volume of water) and (ii) directly modulate the environment through flowrate rather than increasing the swimming Text 6 speed (i.e., task constraint) that indirectly modifies the fluid flow.…”

“…The first part of testing took place in a 50 m indoor swimming pool, before relocating to a specially designed swimming flume (recently used by Guignard et al, 2017) for the second part of the experimentation. Water is circulated through the flume (Italian National Olympic Committee, CONI, Italy), being pumped by an engine, at speeds from 0 to 40 Hz (0 to 1.9 m.s -1 ).…”

“…1.58 ± 0.05; 1.65 ± 0.03; 1.69 ± 0.04 and 1.77 ± 0.03 m.s -1 (i.e., mean ± SD values of all swimmers). Two experimenters imposed the target speeds, the first acting as a pacer and the second controlling the speed at the end of the pool, as extensively described in Guignard et al (2017). Swimmers were tasked to globally follow the pace with a tolerance of 0.5 m from the position of a pole hold by the first experimenter.…”