307 Journal of Applied Biomechanics, 2008, 24, 307-315 © 2008 Human Kinetics, Inc. This study compared the conventional track and a new one-handed track start in elite age group swimmers to determine if the new tech- nique had biomechanical implications on dive performance. Five male and seven female GB national qualiiers participated (mean ± SD: age 16.7 ± 1.9 years, stretched stature 1.76 ± 0.8 m, body mass 67.4 ± 7.9 kg) and were assigned to a control group (n = 6) or an inter- vention group (n = 6) that learned the new one- handed dive technique. All swimmers under- went a 4-week intervention comprising 12 ± 3 thirty-minute training sessions. Video cameras synchronized with an audible signal and timing suite captured temporal and kinematic data. A portable force plate and load cell handrail mounted to a swim starting block collected force data over 3 trials of each technique. A MANCOVA identiied Block Time (BT), Flight Time (FT), Peak Horizontal Force of the lower limbs (PHF) and Horizontal Velocity at Take-off (Vx) as covariates. During the 10-m swim trial, signiicant differences were found in Time to 10 m (TT10m), Total Time (TT), Peak Vertical Force (PVF), Flight Distance (FD), and Horizontal Velocity at Take-off (Vx) (p < .05). Results indicated that the conven- tional track start method was faster over 10 m, and therefore may be seen as a superior start after a short intervention. During training, swimmers and coaches should focus on the most statistically signiicant dive performance variables: peak horizontal force and velocity at take-off, block and light time. Galbraith, Scurr, Hencken, and Wood are with the Department of Sport and Exercise Science, University of Portsmouth, Portsmouth, U.K., and Graham-Smith is with Centre for Reha- bilitation and Human Performance Research, University of Salford, Greater Manchester, U.K. Biomechanical Comparison of the Track Start and the Modiied One-Handed Track Start in Competitive Swimming: An Intervention Study H. Galbraith, 1 J. Scurr, 1 C. Hencken, 1 L. Wood, 1 and P. Graham-Smith 2 1 University of Portsmouth and 2 University of Salford Keywords: diving, force platform, kinematics, kinetics In competitive swimming, the fundamental goal is to cover a set distance in the least amount of time. When evaluating a swimmer’s performance, several measures are considered including inal time, strategy, and techni- cal components. The latter includes speed, stroke mechanics, starting, turning, and inishing (Smith et al., 2002). Emphasis during training is often placed on high mileage, speed work, and stroke drills, leaving very little time for perfecting the starting technique (Maglis- cho, 2003). The start is an area where small yet signii- cant gains can be made. Researchers have found that through consistent dive practice an elite swimmer can reduce their total race time by a minimum of 0.10 s (Blanksby et al., 2002; Maglischo, 2003). At the elite level, this improvement could represent the time differ- ence between a irst and third place in a sprint event (Thayer & Hay, 1984; Cossor et al., 1999; Breed & McElroy, 2000; Breed & Young, 2003; Lyttle & Ben- januvatra, 2005). As cited by Lyttle & Benjanuvatra (2005), the three main starting techniques currently used by elite swim- mers include the track start (both rear and front weighted), the grab start, and the swing start (mainly used during relays). It has been suggested that neither preference nor experience is a good indicator of the best dive style for a swimmer and guided experimentation may be most beneicial (Welcher et al., 1999). The ind- ings to date have shown that regardless of swim start choice, the swimmer’s goal is to react quickly to the starting signal, leave the blocks rapidly generating as much horizontal velocity as possible, gain maximal light distance while using an optimal projection angle on entry, and maintain a streamline position that will minimize the loss of horizontal velocity associated with drag on water entry (Pearson et al., 1998). Over the last 40 years, the swim start technique has evolved. The original arm swing diving technique was ORIGINAL RESEARCH