Table 1 Number of frames automatically tr acked and number of manual interventions for each software and underwater movement. Movement Software Automatic tr acks Manual interventions Percentage of manual interventions Odds ratio 95% CI Front crawl swimming DVP COM 556 432 95 219 14.6 33.6 .34 * .26 – .44 Elliptical machine DVP COM 244 158 50 136 17.0 46.3 .24 * .16 – .35 Towed swimming DVP COM 494 496 2 0 0.4 0.0 ≈ž 1 – ≈ž Flutter kick swimming DVP COM 332 310 57 79 14.7 20.3 .67 * .46 – .98 Treadmill DVP COM 506 473 4 37 0.8 7.3 .10* .04 – .29 Walking DVP COM 591 547 9 53 1.5 8.8 .16 * .08 – .32 Total DVP COM 2723 2416 217 524 7.4 17.8 .37 * .31 – .44 CI, confidence interval for odds ratio. * p 0.05, significantly different from 1