BIOMECHANICAL FACTORS INFLUENCING BREASTSTROKE TURNS BY AGE-GROUP SWIMMERS

Because turning can account for one-third of breaststroke race time in 25 m pools, it is possible that enhancing turning techniques can impr ove performance significantly. Underwater video cameras and a force pl atform were used to analyze turning techniques of 23 age-group breasts trokers during three 50 m push-start maximum-effort swims. The criteri on measure was the time elapsed between passing the 5 m mark on the ap proach and departure from the wall (5 m round-trip time [RTT]), Correl ations revealed significant commonality of variance (p <.01) between t he 5 m RTT and the 2.5 m RTT, 50 m times average single-stroke velocit y, peak reaction force, pivot time, impulse, peak horizontal velocity off the wall. arm and leg split-stroke resumption distances, surfacing distance, surfacing time, and horizontal velocity, height, and mass o f the subjects. All swimmers achieved a net gain at the turn in that t he mean 5 m RTT (20% of the distance) represented 18.26% of the total swimming time. Following stepwise regression, a successful turn was pr edicted by the equation 17.113 - 0.322 surfacing distance -0.036 heigh t -0.723 surfacing horizontal velocity +0.723 pivot time -0.65 peak ho rizontal velocity.