KINEMATIC DIFFERENCES OF TWO TYPES OF SCULLING ACTIONS IN. DISPLACEMENT. Arellano R.1, Gomes L.2, TaladrÃz S.1, Lopez-Contreras G.1, De la ...
KINEMATIC DIFFERENCES OF TWO TYPES OF SCULLING ACTIONS IN DISPLACEMENT Arellano R.1, Gomes L.2, Taladríz S.1, Lopez-Contreras G.1, De la Fuente B., Cienfuegos J.3, E. Morales.1, Domínguez-Castells R.1 1:FSS-DEFD-UGR (Granada, Spain), 2:UFVSF (Petrolina, Brasil), 3:CAR (Sierra Nevada, Spain) Introduction Sculling is a basic propulsive action with four hand movements: outward, supination, inward and pronation (Arellano et al.,2006). Analysis 3D showed a zigzag path, where hand displacement is mostly forward, with strong hand rotations during the direction’s change (Arellano, 2011). The study aim was to know the effect on kinematic variables of the use of normal and power sculling in displacement. Methods Twenty-three subjects participated in the study. Each performed two 20m trials using a normal sculling [NSc] (arms and elbows fixed close to the water surface making and angular displacement of forearm and hand) and power sculling [PSc] (moving arm, forearm and hand, inward and outward). A linear encoder tethered to the swimmer's belt allowed intra-cyclic speed [V] (m/s) recordings (200 Hz) synchronized with video cameras (HD - 60Hz) to measure sculling frequency [f] (Hz). The average speed and sculling frequency were calculated during six sculling cycles and the sculling length [L] (m/cic) from the equation: L = V/f. Results No significant differences were found between trial mean V [NSc = 0,48 ± 0,09, PSc = 0,47 ± 0,08, t = 0.83 (p=0.42)] Meanwhile f and L were statistical different [fNSc = 1,32 ± 0,17, fPSc = 1,10 ± 0,13, t(22) = 7.57 (p < 0.01), LNSc = 0,36 ± 0,07, LPSc = 0,43 ± 0,07, t(22) = -5.44 (p < 0.01)]. Low correlation values were obtained between variables [r (NSc,V,f) = 0.454 (p = 0.05) and r (PSc,V,f) = 0.300 (p > 0.05)]. Discussion The type of sculling action studied did not affect average velocity, however the sculling frequency and length were modified. The longer hand’s displacement observed results in slower frequencies, a more similar hand path action plus bigger arm muscles contribution, more similar to the formal strokes than the normal sculling with a more analytical and isolated hand/forearm movement. It is recommended to apply this type of power sculling on stroke technique development instead of normal sculling even though further studies should be performed. Acknowledgement: Project funded by Spanish Ministry of Science and Innovation, VI National Plan for Research, Development and Technological Innovation (I+D+i) 20052008, Ref: DEP2009-08411. References Arellano, R. Transferring applied hydrodynamics to technical training: “The Sculling Project”. Portuguese Journal of Sport Sciences, Porto, n.11 (sup. 3), p.69-72, 2011. Arellano, R.; Terrés-Nicoli, J.; Redondo, J. Fundamental Hydrodynamics of Swimming Propulsion. In: Biomechanics And Medicine In Swimming, 10., 2006, Porto. Proceedings of Biomechanics and Medicine in Swimming X. Porto: Faculty of Sports Sciences and Physical Education – University of Porto, 2006. p. 15 - 20.
