## 3 Results
### Kinematic Analysis  
#### 3.2.1 Linear Analysis  
The behaviour of joints during the feedforward phase of GI is illustrated in Figures 4-6, which present the results of the linear analysis (detailed information is available in Tables S3-S5 in the Supplementary Materials). The findings indicate that individuals post-stroke exhibited greater joint displacement, both in terms of TDISP and dynamic measures, such as MDISP and AMPL. Figure 3: COP total displacement trajectories in the mediolateral (\(X\)-axis) and anteroposterior (\(Y\)-axis) directions for the healthy and stroke groups. Each coloured line represents the mean trajectory of an individual across ten trials, illustrating the variability in CoP displacement during the feedforward phase (\(-600\) ms to \(+50\) ms) of GI. Head, Pelvis, and Trunk Joints  
In the sagittal plane, the stroke group exhibited a tendency toward head FLE, while the healthy group showed a preference for EXT; however, these POS differences were not consistently significant (\(p>0.05\)). For the head, significantly greater values were observed for TDISPL (\(p=0.019\)), MDISP (\(p=0.019\)), and AMPL (\(p=0.009\)). Similarly, for the trunk, TDISPL (\(p=0.004\)), MDISP (\(p=0.004\)), and AMPL (\(p=0.002\)) were significantly higher. The pelvis also showed significantly elevated values for TDISPL (\(p=0.017\)), MDISP (\(p=0.014\)), and AMPL (\(p=0.009\)) in the stroke group (Figure 4). For the head, TDISPL (\(p=0.006\)), MDISP (\(p=0.005\)), and AMPL (\(p=0.006\)) were significantly greater. Similarly, for the trunk, TDISPL (\(p=0.016\)), MDISP (\(p=0.016\)), and AMPL (\(p=0.012\)) were also significantly higher in the stroke group (Figure 3). In the transverse plane, the stroke group showed exaggerated rotational patterns, with significantly higher TDISPL values for the head (\(p=0.009\)), trunk (\(p=0.037\)), and pelvis (\(p=0.011\)). MDISP and AMPL were also significantly greater for the head (\(p=0.009\) and  
Figure 4: Median, 25 th, and 75 th percentiles of position (\(\top\)), total displacement (\(\top\)), mean displacement (\(\top\)), and amplitude (\(\top\)) values of linear outcome of head, trunk, and pelvis joints. EXT, extension; FLE, flexion; RT, right tilt; LT, left tilt; LR, left rotation: RR, right rotation; RV, retroversion; AV, anteversion; AD, adduction; ABD, abduction; \(\top\)-value \(<0.05\): Mann–Whitney test. \(p=0.004\)), trunk (MDISP: \(p=0.040\); AMPL: \(p=0.008\)), and pelvis (MDISP: \(p=0.009\); AMPL: \(p=0.002\)) (Figure 4). Lower Limb Joints  
In the sagittal plane, the stroke group demonstrated a tendency towards increased hip FLE in both swing and stance phases and decreased swing ankle DF; however, these POS differences were not statistically significant (\(p>0.05\)). For the hip, significantly higher values were noted in the swing limb for MDISP (\(p=0.019\)) and AMPL (\(p=0.044\)). For the knee, AMPL was significantly elevated in the stance limb (\(p=0.021\)). For the ankle, significantly greater values were observed in the swing limb for TDISPL (\(p=0.034\)), MDISP (\(p=0.037\)), and AMPL (\(p=0.028\)) (Figure 5). Figure 5: Median, 25 th, and 75 th percentiles of position (\({}^{\circ}\)), total displacement (\({}^{\circ}\)), mean displacement (\({}^{\circ}\)), and amplitude (\({}^{\circ}\)) values of linear outcome of lower limb joints. FLE, flexion; EXT, extension; AD, adduction; ABD, abduction; IR, internal rotation; ER, external rotation; DF, dorsiflexion; PF, plantar flexion; IN, inversion; EV, eversion; \({}^{\star}\)\(p\)-value \(<0.05\): Mann–Whitney test. In the frontal plane, the stroke group exhibited significantly greater TDISPL, MDISP and AMPL for the ankle in both the swing limb (\(p\) = 0.009; \(p\) = 0.026; \(p\) = 0.006, respectively) and stance limb (\(p\) = 0.007; \(p\) = 0.002; \(p\) = 0.002, respectively) (Figure 4).