title: The key kinematic determinants of undulatory underwater swimming at maximal velocity.
abstract: The optimisation of undulatory underwater swimming is highly important in competitive swimming performance. Nineteen kinematic variables were identified from previous research undertaken to assess undulatory underwater swimming performance. The purpose of the present study was to determine which kinematic variables were key to the production of maximal undulatory underwater swimming velocity. Kinematic data at maximal undulatory underwater swimming velocity were collected from 17 skilled swimmers. A series of separate backward-elimination analysis of covariance models was produced with cycle frequency and cycle length as dependent variables (DVs) and participant as a fixed factor, as including cycle frequency and cycle length would explain 100% of the maximal swimming velocity variance. The covariates identified in the cycle-frequency and cycle-length models were used to form the saturated model for maximal swimming velocity. The final parsimonious model identified three covariates (maximal knee joint angular velocity, maximal ankle angular velocity and knee range of movement) as determinants of the variance in maximal swimming velocity (adjusted-r2 = 0.929). However, when participant was removed as a fixed factor there was a large reduction in explained variance (adjusted r2 = 0.397) and only maximal knee joint angular velocity continued to contribute significantly, highlighting its importance to the production of maximal swimming velocity. The reduction in explained variance suggests an emphasis on inter-individual differences in undulatory underwater swimming technique and/or anthropometry. Future research should examine the efficacy of other anthropometric, kinematic and coordination variables to better understand the production of maximal swimming velocity and consider the importance of individual undulatory underwater swimming techniques when interpreting the data.
authors.affiliation: a Neuromuscular Research Laboratory, Warrior Human Performance Research Center , University of Pittsburgh , Pittsburgh , PA , USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Connaboy
authors.affiliation: b School of Psychology, Sport & Exercise , Staffordshire University , Staffordshire , UK.|c Centre of Aquatics Research & Education , University of Edinburgh , Edinburgh , UK.
authors.forename: Roozbeh
authors.initials: R
authors.lastname: Naemi
authors.affiliation: d School of Life, Sport & Sciences , Edinburgh Napier University , Edinburgh , UK.
authors.forename: Susan
authors.initials: S
authors.lastname: Brown
authors.affiliation: c Centre of Aquatics Research & Education , University of Edinburgh , Edinburgh , UK.
authors.forename: Stelios
authors.initials: S
authors.lastname: Psycharakis
authors.affiliation: c Centre of Aquatics Research & Education , University of Edinburgh , Edinburgh , UK.|e Faculty of Life & Health Sciences , Ulster University , Belfast , UK.
authors.forename: Carla
authors.initials: C
authors.lastname: McCabe
authors.affiliation: f Institute for Sport, Physical Education & Health Sciences , University of Edinburgh , Edinburgh , UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Coleman
authors.affiliation: c Centre of Aquatics Research & Education , University of Edinburgh , Edinburgh , UK.|g Faculty of Health Sciences , University of Sydney , Sydney , Australia.
authors.forename: Ross
authors.initials: R
authors.lastname: Sanders
mesh_terms: D000293:Adolescent; D000842:Ankle / Q000502:physiology*; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D008954:Models, Biological; D015233:Models, Statistical; D016059:Range of Motion, Articular; D013550:Swimming / Q000502:physiology*; D055815:Young Adult
keywords: Maximum velocity; cycle frequency; cycle length; sport science support