FINA recently approved the backstroke ledge (Omega OBL2) to improve backstroke start performance in competition, but its performance has not been thoroughly evaluated. The purpose of this study was to compare the mechanics of starts performed with and without the OBL2. Ten high-level backstroke swimmers performed three starts with, and three starts without, the OBL2. A wall-mounted force plate measured the lower limb horizontal impulse, vertical impulse, take-off velocity and take-off angle. Entry distance, time to 10 m and start of hip and knee extension were recorded using video cameras. Starts performed with the OBL2 had a 0.13 s lower time to 10 m, 2.5% less variability in time to 10 m and 0.14 m greater head entry distance. The OBL2 provides a performance advantage by allowing an increased head entry distance rather than larger horizontal impulse on the wall. This may be due to the swimmers assuming different body positions during the start manoeuvre. Additional studies are needed to evaluate factors that contribute to improved performance when using the OBL2. Swimmers should train with the OBL2 and use it in competition to ensure optimal start performance.

Backstroke starts involve the athlete starting from a flexed position with their feet against the pool wall and then extending their ankles, knees, hips and back to push off; however, swimmers can start in different positions. The purpose of this study was to evaluate the performance impact of different knee extension angles in the setup position for a backstroke start. Ten backstroke swimmers completed maximum-effort starts in each of two setup positions: one with the knees maximally flexed, and one with the knees less flexed. The start handles and touchpad were instrumented with multi-axial force sensors. Activity of major hip and knee extensors was measured using surface electromyography. Body position in the sagittal plane was recorded using high-speed cameras. There was no overall difference in time to 10 m between the two conditions (p = 0.36, dz = 0.12), but some participants showed differences as large as 0.12 s in time to 10 m between start conditions. We observed that starts performed from a setup position with less knee flexion had an average 0.07 m greater head entry distance (p = 0.07, dz = 0.53), while starts from a setup position with maximal knee flexion had an average 0.2 m/s greater takeoff velocity (p = 0.02, dz = 0.78). Both head entry distance and takeoff velocity are related to start performance, suggesting each position may optimize different aspects of the backstroke start. Coaches should assess athletes individually to determine which position is optimal.

The backstroke swim start is an explosive, discrete skill. Swimmers often perform plyometric warm-up protocols, such as repeated jumps, prior to their race. The purpose of this study was to determine the impact of repeated drop jumps performed immediately prior to a backstroke start. Nine elite backstroke swimmers performed three starts after a standard swimming warm-up, and three after an additional plyometric warm-up (three drop jumps from a height of 0.4 m) prior to each start. Timing and peak activation of gluteus maximus and vastus lateralis activity were measured using wireless surface electromyography. Hip and knee angles, wall contact time, head entry distance and time to 10 m were recorded using digital video cameras positioned at the side of the pool. On average, starts performed after the plyometric warm-up had a 0.1±0.09 s longer time to 10 m, peak gluteus maximus activity occurred 0.09±0.13 s later and peak vastus lateralis activity occurred 0.15±0.16 s earlier. Head entry distance was inversely proportional to time to 10 m (r =-0.80) across both conditions and should be considered as a training target. Performing plyometric warm-ups immediately prior to races may have a negative impact on backstroke start time to 10 m.

Introduction: The purpose of the present study was to compare the balance performance of control subjects and varsity figure skaters after spinning on a turntable for 6 seconds. It was hypothesized figure skaters would demonstrate better balance control after spinning. Methods: 9 female figure skaters and 9 female control subjects stood as still as possible for 15 seconds on a Kistler force plate during both a control condition and after spinning for 6 seconds on a turntable. Balance performance was quantified by the percentage of total time the center of pressure (CoP) was within a 5mm radius of the center of their base of support (BoS). Results: In the control condition, figure skaters and control participants did not have significantly different balance ability. In the post-spin condition, figure skaters were significantly better at maintaining their CoP within a smaller area. Conclusions: These results are valuable from a training and coaching perspective because they suggest that balance performance after spinning can be improved with training.