Influence of task and sex on push-off mechanics and stability control strategies during elite curling delivery.

This study investigated the biomechanical mechanisms of push-off mechanics and dynamic stability control strategies in elite curlers across various delivery tasks, while examining the modulating effect of sex. Twenty elite curlers (10 males, 10 females) participated. A 3D motion capture system and a plantar pressure system were used for synchronized acquisition of kinematic and plantar loading data during Draw, Guard, and Take-out tasks. Joint angular velocities and Center of Mass (CoM) trajectories were quantified using OpenSim musculoskeletal modeling. Data were analyzed via 2 × 3 mixed-design ANOVA and Pearson correlation. (1) Push-off mechanics: Take-out tasks were characterized by significantly greater push-off velocities (P < 0.01) and reduced push-off durations (P = 0.012), while vertical plantar kinetic metrics (including peak forefoot loading) remained statistically invariant across tasks (P > 0.05). (2) Stability control: Take-out tasks yielded increased trunk angular velocity and vertical CoM fluctuations; however, mediolateral (ML) variability was significantly lower than in Draw tasks (P = 0.008). Correlation analysis revealed that push-off velocity was inversely correlated with ML instability (r = - 0.460,P < 0.001). Delivery tasks significantly modulate biomechanical strategies in elite curlers. In Take-out tasks, push-off strategy shifts from quasi-static propulsion to high-velocity ballistic impulse. This study identifies a "momentum-stability effect," where high sliding velocity enhances ML stability via increased forward inertia, thereby transcending the classical speed-accuracy trade-off. Furthermore, male and female athletes demonstrate distinct "velocity-driven" and "stringent lateral trajectory control" strategies, respectively.