IMU-Driven Biomechanical Smoothness Assessment for Cycling Pedaling Technique: An Evaluation Model with Real-Time Monitoring

This study proposed an inertial sensor-based cycling pedaling technology smoothness assessment method, aiming to accurately quantify the crank rotation angular velocity fluctuation during cycling, and provided an objective basis for cycling technology assessment. In this study, we constructed models to evaluate single-lap pedaling smoothness (SSP), left- and right-foot pedaling smoothness (SLP, SRP), and pedaling balance index (PBI), and collected crank kinematic data from 10 subjects at 90 W and 130 W power and 60 rpm speed using inertial measurement unit, and also collected data from 3 times of 1000 m training rides of outstanding athletes. The validity of the model was verified by one-way analysis of variance (ANOVA), and the results showed that at 90 W, SSP (F (9,90) = 2.558, p = 0.011), SRP (F (9,90) = 2.399, p = 0.017), and SLP (F (9,90) = 5.800, p < 0.001) were significantly different from each other, and at 130 W, SSP (F (9,90) = 2.399, p = 0.017) was significantly different from each other, and SSP (F (9,90) = 5.800, p < 0.001) was significantly different from each other. (9,90) = 4.610, p < 0.001), SRP (F (9,90) = 3.636, p = 0.001) and SLP (F (9,90) = 11.087, p < 0.001) at 130 W of power, with SLP demonstrating a highly significant difference (p < 0.001) in both power conditions. In addition, the technique was successfully applied to the athletes' actual riding, effectively monitoring the dynamic changes of SSP, SRP, SLP and PBI throughout the whole ride, confirming its usefulness in real riding scenarios. This study constructed a new evaluation system for the quantitative analysis of cycling pedaling technique and verified the potential application of inertial sensors in the field of sports biomechanics to provide scientific support for the optimization of cycling training.