title: Relationships between coordination, active drag and propelling efficiency in crawl.
abstract: This study examines the relationships between the index of coordination (IdC) and active drag (D) assuming that at constant average speed, average drag equals average propulsion. The relationship between IdC and propulsive efficiency (ep) was also investigated at maximal speed. Twenty national swimmers completed two incremental speed tests swimming front crawl with arms only in free condition and using a measurement of active drag system. Each test was composed of eight 25-m bouts from 60% to 100% of maximal intensity whereby each lap was swum at constant speed. Different regression models were tested to analyse IdC-D relationship. Correlation between IdC and ep was calculated. IdC was linked to D by linear regression (IdC=0.246·D-27.06; R(2)=0.88, P<.05); swimmers switched from catch-up to superposition coordination mode at a speed of ∼1.55ms(-1) where average D is ∼110N. No correlation between IdC and ep at maximal speed was found. The intra-individual analysis revealed that coordination plays an important role in scaling propulsive forces with higher speed levels such that these are adapted to aquatic resistance. Inter-individual analysis showed that high IdC did not relate to a high ep suggesting an individual optimization of force and power generation is at play to reach high speeds.
authors.affiliation: Centre d'Etude des Transformations des Activités Physiques et Sportives (CETAPS) - EA 3832, University of Rouen, Faculty of Sports Sciences, France. Electronic address: ludovic.seifert@univ-rouen.fr.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Seifert
authors.affiliation: Centre d'Etude des Transformations des Activités Physiques et Sportives (CETAPS) - EA 3832, University of Rouen, Faculty of Sports Sciences, France; Faculty of Sports Sciences, Strasbourg Marc Bloch University, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Schnitzler
authors.affiliation: Laboratoire d'Informatique, de Traitement de l'Information et des Systèmes (LITIS) - EA 4108, Institut National des Sciences Appliquées de Rouen (INSA), Rouen, France.
authors.forename: Gautier
authors.initials: G
authors.lastname: Bideault
authors.affiliation: LEMH EA 3608, Faculty of Sports Sciences, University of Lille, France.
authors.forename: Morgan
authors.initials: M
authors.lastname: Alberty
authors.affiliation: Centre d'Etude des Transformations des Activités Physiques et Sportives (CETAPS) - EA 3832, University of Rouen, Faculty of Sports Sciences, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Chollet
authors.affiliation: Academy of Physical Education, University of Applied Sciences Amsterdam, Amsterdam, The Netherlands.
authors.forename: Huub Martin
authors.initials: HM
authors.lastname: Toussaint
mesh_terms: D000328:Adult; D000465:Algorithms; D001696:Biomechanical Phenomena; D049628:Body Size; D006801:Humans; D008297:Male; D009068:Movement; D012044:Regression Analysis; D013550:Swimming; D014741:Video Recording; D014867:Water; D055815:Young Adult
chemical_list: D014867:Water
keywords: Biomechanics; Drag; Motor control; Propulsion; Swimming