Efectos causales de variables biomecánicas sobre la velocidad inicial en patinadores de velocidad: un enfoque bayesiano guiado por diagramas acíclicos dirigidos (DAGs)

Introduction: The technical complexity of speed skating requires solid technical mastery and the development of biomechanical variables linked to initial acceleration, particularly stability, flight time, and contact time. Objective: To estimate the combined effect of TC_CMJ, TV_SJ, and APY_D_FRONTAL on VELOCIDAD_20_M, adjusting for Age, Sex, and Body Fat Index. Methodology: An observational, analytical, cross-sectional study designed to identify the effects of biomechanical variables on the start phase. The sample size was determined by the availability of athletes in the evaluated competitive group, with 25 participants. Results and discussion: In the SJ, longer flight time was associated with lower initial speed, suggesting reduced efficiency of the horizontally oriented impulse. The Y-balance test (right anterior reach) showed that greater reach distances were related to higher speed over the first 20 meters, reinforcing the importance of dynamic balance and postural control during initial acceleration. In the CMJ, shorter contact time was associated with higher speed; however, the model did not provide sufficient evidence to confirm a credible effect at the 95% level. The adjustment variables (Age, Sex, and Body Fat Index) showed no credible effects on the main outcome, supporting their role as confounder controls rather than primary predictors. Conclusions: Training programs should emphasize strength development along a horizontal vector, prioritize reactive training, and enhance anterior-direction postural development. For monitoring purposes, the SJ and Y-balance test are proposed as key tools, as they help track each athlete’s status in relation to 20-meter start speed.