Transition phase – A new phase from start/turn to free swimming in competitive swimmers

Abstract

For the best swimming performance, it is important to keep the highest possible velocity in each portion of the swimming event. Traditionally, the segments of swimming events are divided into: starting, free swimming and turning portions. Starting and turning mainly belong to underwater, while free swimming to surface swimming. The swimming process of transitioning from underwater to free swimming in this thesis is defined as breakout phase or transitioning swimming phase.Aim: The purpose of this study was to examine breakout phase in the four strokes and two genders regarding kinematics, coordination and segmental factors. This purpose was achieved through three main aims of the study. The first aim was to characterize the kinematics, coordinative and segmental variables of the breakout phase in elite competitive swimmers of both genders (Chapter 4). The second aim was to compare the kinematic and coordinative parameters of elite competitive swimmers during the transition phase and the free swimming phases (Chapter 5). The third aim was to examine the role of the segmental, kinematic and coordinative parameters on the swimming velocity during the pre-transition and transition phases of the push start (Chapter 6).Methods: 74 competitive swimmers (33 males and 41 females) with a personal best time within the 85% of world record participated in this study. Swimmers performed 4 x 25 m maximal efforts (one of each stroke in random order) from a push start and were recorded (50 Hz) by two sequential video cameras in sagittal plane. The average velocity, stroke length, stroke frequency, the relative duration (%) of the stroke phases, segmental variables (body and trunk inclinations, body depths) as well as the inter-limb discrete relative phases were calculated with direct linear transformation (DLT) algorithms for the breakout and free-swimming phases.Results (Study 1 -Chapter 4) Stroke rate was higher in males than in females in freestyle (F=10.24, p=0.002), backstroke (F=10.80, p=0.002) and breaststroke (F=4.70, p=0.034) during the transition