## 3 Results  
Before reporting this study's results, it should be noted that participants did not observe or report any adverse events during the investigation that could have affected the results presented in the sections below. Differences Between Values of Spatiotemporal Parameters for the Perturbed Limb, the Responding Limb, and the Unperturbed Limb  
A one-way ANOVA revealed a significant effect of the group (perturbed limb, responding limb, and unperturbed limb) on the values of the spatiotemporal parameters: F(22, 100) = 22.624, \(p\) = 0.0001, \(\eta_{p}^{2}\) = 0.83. The presence of perturbation caused a significant increase in the stride duration for the perturbed and reactive limbs compared to the stride duration for the treadmill gait (Figure 4, Table 2). When compared to the treadmill gait, the support phase duration increased for both lower limbs but this was only significant for the perturbed limb. The time of the double stance phase was the longest for the perturbed limb and the shortest for the treadmill gait. The stride was the longest for the perturbed limb. It was  
\begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**Parameter** & **Perturbed Limb (L)** & **Reactive Limb (R)** & **Treadmill Gait (N)** & **L vs. R** & **L vs. N** & **R vs. N** \\ \hline Stride duration [s] & 1.63 \(\pm\) 0.1 & 1.65 \(\pm\) 0.13 & 1.11 \(\pm\) 0.04 & - & \(p\) = 0.0001 & \(p\) = 0.0001 \\ Stance phase [s] & 1.08 \(\pm\) 0.29 & 0.98 \(\pm\) 0.24 & 0.73 \(\pm\) 0.04 & - & \(p\) = 0.0023 & - \\ Swing phase [s] & 0.4 \(\pm\) 0.02 & 0.44 \(\pm\) 0.08 & 0.38 \(\pm\) 0.01 & - & - & - \\ Double stance [s] & 0.18 \(\pm\) 0.02 & 0.41 \(\pm\) 0.21 & 0.15 \(\pm\) 0.05 & \(p\) = 0.0053 & - & \(p\) = 0.0001 \\ Stride [m] & 1.31 \(\pm\) 0.21 & 1.25 \(\pm\) 0.21 & 1.06 \(\pm\) 0.04 & - & \(p\) = 0.0027 & - \\ Stride width [m] & 0.15 \(\pm\) 0.03 & 0.16 \(\pm\) 0.03 & 0.13 \(\pm\) 0.03 & - & - & \(p\) = 0.0017 \\ Step [m] & 0.59 \(\pm\) 0.03 & 0.56 significantly longer compared to that recorded for the treadmill gait. Stride width was significantly longer for the perturbed limb compared to that recorded for the treadmill gait. The percentage of stance phase duration was the longest for the perturbed limb and was significantly longer than that recorded for the reactive limb and the treadmill gait. The percentage of double support phase duration was the longest for the reactive limb, and it was significantly longer than that recorded for the perturbed limb and the treadmill gait. Differences Between the Angles and Torques Curves for the Perturbed Limb, the Responding Limb, and the Unperturbed Limb  
Following the SPM analysis, it was shown that there are statistically significant differences for all analyzed kinematic and kinetic parameters between the gait cycles for the perturbed limb, the reactive limb, and the treadmill gait (Figure 5). For the ankle joint, statistically significant differences between the curves for the affected and reactive limbs occur from 42% to 80% of the gait cycle. For the knee joint, the differences are earlier, between 17% to 43% of the gait cycle. For the hip joint, they are in a similar range as for the ankle joint, from 11% to 74% of the gait cycle. When considering the differences between curves containing perturbations in the gait cycle and those without, at the ankle joint they occur mainly in the swing phase, involving 58% to 85% of the gait cycle. However, there are differences for the entire length of the gait cycle, excluding the initial contact and the loading response phases (0% to 10%) for the knee and hip joints. When comparing the gait cycle for the reactive limb with the gait cycle without perturbation in the ankle joint, statistically significant differences are found for the entire gait cycle, except for the initial contact and part of the loading response phase (0% to 4%).