# Kinematic Determinants of the Swimming Push Start in Competitive Swimmers
###### Abstract  
(1) Background: The aim of the present research is to describe the kinematic characteristics of push start in competitive swimmers and to examine the role of the push start sub-phases on the overall start performance. (2) Methods: Seventy-four swimmers (33 males and 41 females) of national and international level performed one 25 m trial at maximum velocity with a push start at butterfly, backstroke and/or front-crawl techniques and were filmed with two sequential underwater cameras during the glide, leg kicking, transition and surface swimming phases. (3) Results: Backstroke starts showed greater energyon distances but slower times to 10 m than the remaining strokes. Distances and average velocities in each of the start sub-phases predicted the overall push start performance (times to 10 m) on the butterfly (R\({}^{2}\): 0.50) and backstroke (R\({}^{2}\): 0.58) strokes, with the velocity of the leg kicking phase having a statistical effect on both regression analysis and the glide and transition phases in backstroke. (4) Conclusions: Push starts performed in a dorsal body position seemed to present kinematic differences with ventral techniques and a greater technical complexity with all glide, leg kicking and transition sub-phases meaningfully impacting the overall push start performance. This should be considered when executing the daily training repetitions with swimmers in water.  
underwater swimming; undulatory kicking; glide; swimming turn; performance Article  
[PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON]; [PERSON] Kinematic Determinants of the Swimming Push Start in Competitive Swimmers. _Appl. Sci._**2022**, 12, 9278. [[https://doi.org/10.3390/app12189278](https://doi.org/10.3390/app12189278)]([https://doi.org/10.3390/app12189278](https://doi.org/10.3390/app12189278))  
Academic Editor [PERSON]  
Received: 11 August 2022  
Accepted: 13 September 2022  
Published: 16 September 2022  
**Published: 16 September 2022**  
a common characteristic of elite training programs [17]. Therefore, when beginning each of the training repeats, swimmers do not get out of water and perform a dive start, but they execute the so-called push start [3; 18]. This procedure has been extensively employed in the literature during experiments analyzing underwater undulatory swimming [19; 20; 21], and it consists of swimmers beginning in the water and pushing off the wall in the streamline position to achieve a depth between 0.5 m and 1 m. Despite its daily and repeated use in training, there is no evidence in the literature of differences between the push and dive start in terms of the overall performance at 5 m, 10 m or 15 m, neither is there information about the underwater and/or surface swimming segments travelled in each type of start in the different strokes. Kinematic data about the push start could be relevant, for example, for comparison purposes between dive or push start training repeats or for specific instructions in relation to the gliding, underwater and surface swimming subsections.  
Therefore, the aim of the present research is to describe the kinematic characteristics of push start in competitive swimmers and to examine the role of the push start sub-phases on the overall start performance. It was hypothesized that the leg kicking phase is the most important sub-phase, although the glide, transition and surface swimming sub-phases can have a meaningful impact on the push start performance.