Analysis of swim turning, underwater gliding and stroke resumption phases in top division Italian swimmers using a wearable inertial device

Improving performance is a difficult task for élite swimmers. The study of turning, underwater gliding and stroke resumption kinematics may lead to the reduction of the relevant durations. Common video analysis is sometimes inadequate to investigate motor tasks. This work aimed at describing the mentioned phases in top division swimmers using a wearable inertial device. Eight élite swimmers were selected so as to cover all the four swimming styles. The device was positioned on the lower trunk and a 50m trial at the maximum velocity was executed. The angular velocity about each axis was post-processed and both time and kinematic parameters were extracted for each phase, characterizing each swimming style. Strength points of the approach are: simple description of the turning kinematics; possibility to extract performance-related parameters; simplicity of use for the operator; the minimal encumber for the athlete.