Case Report: Impact of dolphin kick implementation during backstroke finishes on swimming performance. From regional to olympic-level swimmers. A comparative case study.

According to the World Aquatics (WA) an updated swimming regulation (SW) concerning the backstroke finish has been implemented, allowing, the swimmers to fully submerge their bodies at once when some part of their head pass the 5-meter mark immediately before touching the wall. Therefore, the present comparative case study aims to apply the new regulation on backstroke finish, examining the swimming efficiency and underwater kinematics of an elite Olympic-level swimmer, and comparing the data with the published ones from a previous study on regional-level swimmers. A 19-year-old male Olympic-level backstroke swimmer performed three all-out 20 m backstroke swims: (i) touching the wall, breaking the water's surface with one part of their body (Classic), (ii) touching the wall with one hand, submerging the body two strokes after passing the last 5 m (Dive-One Hand) and (iii) touching the wall on streamline position, submerging the body two strokes after passing the last 5 m (Dive-Streamline) Kinematic analysis of the intermediate 10 m and the last 5 m was conducted using a digital video camera.