title: Effect of hand paddles and parachute on backstroke coordination and stroke parameters.
abstract: Hand paddles and parachutes have been used in order to overload swimmers, and consequently increase the propulsive force generation in swimming. However, their use may affect not only kinematical parameters (average speed, stroke length and stroke rate), but also time gaps between propulsive phases, assessed through the index of coordination (IdC). The objective of this study was to assess the effects of hand paddles and parachute use, isolated or combined, on kinematical parameters and coordination. Eleven swimmers (backstroke 50-m time: 29.16 ± 1.43 s) performed four 15-m trials in a randomised order at maximal intensity: (1) without implements (FREE), (2) with hand paddles (HPD), (3) with parachute (PCH) and (4) with hand paddles plus parachute (HPD+PCH). All trials were video-recorded (60 Hz) in order to assess average speed, stroke rate, stroke length, five stroke phases and index of coordination. When average swimming speed was compared to FREE, it was lower in PCH and HPD+PCH, and higher in HPD. Stroke rate decreased in all overloaded trials compared to FREE. The use of hand paddles and parachute increased and decreased stroke length, respectively. In addition, propulsive phase duration was increased when hand paddles were used, and time gaps shifted towards zero (no time gap), especially when hand paddles were combined with parachute. It is conceivable that the combined use of hand paddles and parachute, once allowing overloading both propulsive and resistive forces, provides a specific stimulus to improve muscle strength and propulsive continuity.
authors.affiliation: a Laboratory of Aquatic Activities, Physical Education Faculty, Sports Science Department , State University of Campinas , Campinas , Brazil.|b Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport , University of Porto , Porto , Portugal.
authors.forename: Thiago
authors.initials: T
authors.lastname: Telles
authors.affiliation: a Laboratory of Aquatic Activities, Physical Education Faculty, Sports Science Department , State University of Campinas , Campinas , Brazil.
authors.forename: Renato
authors.initials: R
authors.lastname: Barroso
authors.affiliation: b Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport , University of Porto , Porto , Portugal.|c School of Physical Education , Federal University of Rio Grande do Sul , Porto Alegre , Brazil.
authors.forename: Pedro
authors.initials: P
authors.lastname: Figueiredo
authors.affiliation: a Laboratory of Aquatic Activities, Physical Education Faculty, Sports Science Department , State University of Campinas , Campinas , Brazil.
authors.forename: Diego Fortes de Souza
authors.initials: DF
authors.lastname: Salgueiro
authors.affiliation: b Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport , University of Porto , Porto , Portugal.|d Porto Biomechanics Laboratory (LABIOMEP) , University of Porto , Porto , Portugal.
authors.forename: João Paulo
authors.initials: JP
authors.lastname: Vilas-Boas
authors.affiliation: a Laboratory of Aquatic Activities, Physical Education Faculty, Sports Science Department , State University of Campinas , Campinas , Brazil.
authors.forename: Orival Andries
authors.initials: OA
authors.lastname: Junior
mesh_terms: D001132:Arm / Q000502:physiology*; D001696:Biomechanical Phenomena; D006225:Hand / Q000502:physiology*; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D055070:Resistance Training / Q000295:instrumentation* / Q000379:methods; D019876:Sports Equipment; D013550:Swimming / Q000502:physiology*; D055815:Young Adult
keywords: Swimming; external overload; index of coordination; swimmer