J. Paulo Vilas-Boas
Full professor of Biomechanics and Swimming Science at Porto University, Portugal
Doctor in Sport Sciences (Ph.D), speciality in Sports Biomechanics, with a thesis on Swimming Biophysics (Bioenergetics and Biomechanics) Head of the Biomechanics Laboratory of the Porto University Director of the Master Course in Top Level Coaching of the Porto University Member of the Steering Group Swimming of the Word Commission for Science in Sport. Chairman of the Xth International Symposium on Biomechanics and Medicine in Swimming, Porto 2006
Currently responsible, at the Portuguese Institute of Sports, for the production of the new rules to govern coaches’ education in Portugal.
Member of the board of the Portuguese Swimming Federation, since December 2004
Swimming coach for more than 20 years. Three times “Coach of the Year” of the Portuguese Swimming Coaches Association, and three times National Portuguese Teams Champion. Coached bronze medalists in Dunkerque and Malta European Junior Championships. Olympic Coach at Sydney 2000 and Athens 2004.
ISBS 2009 Conference presentation
J. Paulo Vilas-Boas, Karla de Jesus, Kelly de Jesus, Pedro Figueiredo, Suzana Pereira, Pedro Gonçalves, Leandro Machado, Ricardo Fernandes
University of Porto, Faculty of Sport, CIFI2D, Porto, Portugal
FINA recently changed the rule that governs the starting position for the backstroke starting technique. With this change, swimmers may now decide to start with the feet emerged, which was previously strictly forbidden. This new liberalization naturally determines the rise of a new technical question for swimmers and coaches: do a starting position with the feet emerged allow a better performance, or better performance conditions for the following actions?
To our knowledge no previous scientific results are available concerning this question, allowing to support any technical decision. During this presentation we will try to deliver arguments to support a technical option in this particular topic, based on the research developed by our group, comparing the traditional starting technique with the feet immerged (BSFI), with the one allowed nowadays, with both feet totally, or partially, emerged (BSFE).
Click the play button or the TV image above to view this presentation.
To fulfil this purpose, we studied six experienced male swimmers that maximally performed 4 repetitions of each technique over a distance of 15 meters. All performances were dual-media videotaped (50 Hz) in the sagittal plane, synchronized with kinetic and EMG data simultaneously registered. Kinetic data were assessed using an underwater force plate mounted on a special support on the wall of the pool, allowing the registration of the horizontal component of the forces exerted by the swimmers’ feet. The handgrip system was adapted to reproduce its legal position and configuration, but instrumented with a load cell (Globus, Italy) to allow the assessment of the horizontal component of the forces exerted by swimmers’ upper limbs. Findings pointed out that BSFI was significantly faster till the 5m reference, with less muscular activity, and with a tendency to produce higher forces against the starting wall. No argument was obtained to support the use of the BSFE in swimming competitions.
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