Intra-session reliability of plantar pressure measurements in short-track speed skating

Short-track speed skating involves high biomechanical demands due to repeated transitions between straights and curves. While plantar pressure insoles provide a non-intrusive method to assess loading patterns, their repeatability under real short-track speed skating conditions remain poorly documented. Ten competitive short-track speed skating athletes (5 women and 5 men; age: 18.8 ± 1.2 years; height: 171.2 ± 10.6 cm; mass: 68.8 ± 7.2 kg) performed repeated on-ice trials while equipped with pressure insoles and triaxial accelerometers, with a wearable camera for reference. A pressure-based algorithm automatically segmented half-laps. Intra-session repeatability of plantar pressure, center-of-pressure position, and acceleration signals was assessed using intraclass correlation coefficients, standard error of measurement, and statistical parametric mapping repeated-measures analysis of variance. Within- and between-trial variability was additionally quantified using the root mean square error. No significant trial effects were found, indicating consistent movement patterns across trials. Plantar pressure and center-of-pressure measurements demonstrated fair-to-excellent repeatability (intraclass correlation coefficients greater than 0.70 for mediolateral center-of-pressure), whereas acceleration measurements showed poor repeatability (intraclass correlation coefficient below 0.30). Across all variables, between-trial root mean square error values were lower than within-trial root mean square error values, suggesting that removing and repositioning the insoles did not substantially increase measurement variability. These findings support the repeatability of plantar pressure and center-of-pressure measurements obtained with pressure insoles under real on-ice short-track speed skating conditions.