## 3 Results  
Figure 2 depicts the average angles of the knee, hip, and pelvis joints on the sagittal plane in all the tested tasks and the relative toe-off events. Specifically, considering that some trials were deemed invalid, the angles related to w\({}_{1}\), w\({}_{2}\), r\({}_{1}\), and r\({}_{2}\) resulted from the average of 60, 80, 80, and 40 angle patterns, respectively. Regardless of the motor gesture typology, increasing the treadmill speed from 7 km/h (v\({}_{1}\)) to 8 km/h (v\({}_{2}\)) shortened the duration of the stance phase. During the walking tasks (w\({}_{1}\) and w\({}_{2}\)), independently of task velocity, the athletes started the cycle with the knee and hip flexed at 40\({}^{\circ}\) and 57\({}^{\circ}\) on average, respectively. Instead, in the running task, at the initial contact, the hip appeared less flexed compared to the walking task, having a flexion angle of 48\({}^{\circ}\) and 50\({}^{\circ}\) on average at 7 km/h and 8 km/h velocity, respectively. The initial knee angle instead changed from 35\({}^{\circ}\) at 7 km/h to 50\({}^{\circ}\) at 8 km/h. In all the tested conditions, the athletes preserved the pelvis in anteversion configuration all along the task cycle, as shown in Figure 2c. However, in the walking gestures, the anteversion angle appeared higher with respect to the running tasks. Specifically, walking at 8 km/h required the highest pelvic anteversion angle (27\({}^{\circ}\)). Increasing the task velocity, both in walking and running gestures, had the effect of reducing the maximum extension reached by the hip and knee joints during the terminal stance phase (see Figure 2a,b), as well as increasing the pelvic anteversion (Figure 2c). Moreover, increasing the speed of the motor gestures resulted in increasing the maximum flexion of hip and knee joints during the swing phase. Compared to the other tasks, during running at 8 km/h (r\({}_{2}\)), the athletes reached, on average, the highest knee flexion both during the stance and swing phase and the lowest knee extension (23\({}^{\circ}\)). The ROM results on the sagittal plane of the knee, hip, and pelvis joints are shown in Figure 3. Specifically, in the upper panel, ROMs are compared for each task between the two velocities, while the lower panel reports, the effects of the different motor gestures are compared for each velocity. Considering the walking tasks (Figure 3a), no statistically significant differences were found between ROM median values reached by the joints at 7 km/h and 8 km/h. Indeed, during walking, the knee joint showed an ROM median value of 58\({}^{\circ}\) at both velocities, while the hip median ROM was 70\({}^{\circ}\) at 7 km/h and 64\({}^{\circ}\) at 8 km/h. The pelvis also reached a similar ROM independently of task speed during walking: 8\({}^{\circ}\) in w\({}_{1}\) and 9\({}^{\circ}\) in w\({}_{2}\). Instead, in the running task changing the velocity resulted in significant variations of all joints' ROM (\(p\)-value \(<\) 0.05), as highlighted in Figure 3b. Namely, the ROM median value reduced in all joints when switching from 7 km/h to 8 km/h; the knee ROM appeared reduced by 11\({}^{\circ}\) (69\({}^{\circ}\) in r\({}_{1}\) to 58\({}^{\circ}\) at r\({}_{2}\)), the hip ROM was lowered by 5\({}^{\circ}\) (56\({}^{\circ}\) in r\({}_{1}\) to 51\({}^{\circ}\) at r\({}_{2}\)), and the pelvis ROM dropped by 3\({}^{\circ}\) (from 9\({}^{\circ}\) in r\({}_{1}\) to 6\({}^{\circ}\) in r\({}_{2}\)). As evident in Figure 3c,d, independently of the task velocity, running required a smaller ROM at the knee joint compared to walking. When speed was set at 7 km/h (Figure 3c), the knee ROM median varied from 58\({}^{\circ}\) in w\({}_{1}\) to 56\({}^{\circ}\) in r\({}_{1}\), and the Wilcoxon test  
Figure 2: Joint angles of the lower limbs during the four tasks: w\({}_{1}\) in black (averaged on 60 cycles), w\({}_{2}\) in red (averaged on 80 cycles), w\({}_{2}\) and r\({}_{1}\) in blue (averaged on 80 cycles), and r\({}_{2}\) in green (averaged on 40 cycles).