Effect of three different set-up conditions on the propulsive force measures, reliability, and ecological validity during front crawl tethered-swimming

ABSTRACT

This study analysed the effect of three set-up conditions on the propulsive force (PF) measures, test–retest reliability, and ecological validity during front crawl tethered-swimming (TS). Twenty-five (20.3 ± 3.7 years) swimmers performed TS in three conditions: Slp0 (0º of cable slope), Slp10 (10º of slope) and Slp20 (20º of slope), in two sessions. The second session included a 50-m performance and a questionnaire on the similarity of TS and free-swimming and overall comfort. Peak, mean force, impulse and force development rate, 50-m time and mean velocity, similarity scores and comfort were analysed. Effect of TS condition (p < 0.001) was observed for peak, mean force and force development rate. Regardless of the condition, reliability ranged from good to excellent (ICC = 0.79–0.95) and correlations with performance time (r≥-0.7) and mean velocity (r ≥ 0.63) were significant for all PF variables. The similarity between TS and free-swimming, and overall comfort as perceived by the swimmers, did not differ between conditions. Set-up condition influences the measures of PF in front-crawl TS. All conditions are reliable and present similar associations between PF and performance. Ecological validity indicators were near to the halfway point of the measurement scales independently of the condition.

KEYWORDS:

• Biomechanics
• kinetics
• swimmers
• comfort

Acknowledgments

The authors thank all the swimmers who participated in this study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Geolocation information

South latitude: 27°35ʹ48”

West longitude: 48°32ʹ57”

FILLED UP BY THE RESEARCHER

Participant: _____________ TS condition: ______________

1. During the trial, how do you rate the possibility of performing the arm stroke phases in comparison with the free-swimming trial? Sign the answer for each arm stroke phase individually.

1.1 Beginning of the underwater arm stroke phase (Entry and catch, beginning of the pull)

(0) Nothing similar

(1) Little similar

(2) Similar

(3) Very similar

(4) Equal

1.2 End of the underwater arm stroke phase (end of the pull, push/release)

(0) Nothing similar

(1) Little similar

(2) Similar

(3) Very similar

(4) Equal

1.3 Arm recovery

(0) Nothing similar

(1) Little similar

(2) Similar

(3) Very similar

(4) Equal

1. How do you rate the stroke rate (velocity of the arm during the stroke) on your last try, in comparison with free swimming?

(0) Nothing similar

(1) Little similar

(2) Similar

(3) Very similar

(4) Equal

1. How do you rate the body position (shoulders, trunk and waist) in comparison with the body position during free swimming?

(0) Nothing similar

(1) Little similar

(2) Similar

(3) Very similar

(4) Equal

1. During your last try, how do you rate the capacity to perform the leg kick technique (amplitude, depth, velocity, frequency) in comparison with free swimming?

(0) Nothing similar

(1) Little similar

(2) Similar

(3) Very similar

(4) Equal

1. How do you rate the overall coordination of swimming on your last try, in comparison with free swimming?

(0) Nothing similar

(1) Little similar

(2) Similar

(3) Very similar

(4) Equal

1. Mark on the line below the point which corresponds to the perception of comfort of your last tethered-swimming protocol try. This tool was adapted from the study of Penna et al. (2018), where the comfort level is given by the distance in centimetres from the left side of the line (none) to the right side of the line (maximal comfort). Your answer must not be influenced by your previous answers or any other factor other than your current perception.

Comfort during the trial

Insert here any comments and/or observations regarding any aspect that you felt or perceived during the last try and you think is relevant for the study:

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

Additional information

Funding

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES). Grant number: Finance Code 001Fundação de Amparo à Pesquisa e Inovação do Estado de Santa Catarina – Brasil (FAPESC). Grant number: TO 2017TR788Programa de Bolsas Universitárias de Santa Catarina – Brasil (Uniedu). Grant number: 14786