## 2 Materials and Methods
### Outcome Measures  
Subjects were screened by board-certified rehabilitation operators, with a multimodal assessment schema including clinical measures and instrumental gait analysis. Before starting the study procedures, demographic and clinical variables were collected in order to describe the sample. Each subject was screened at the baseline (T0) and post treatment (T1).  
A clinical evaluation based on the ICF [21] was carried out. For the body function and structure ICF domain, the Motricity Index of Affected lower Limb (MI-AIL) was used to measure limb muscle strength [25], and the Modified Ashworth Scale of Affected lower Limb (MAS-AIL) to evaluate muscle spasticity [26]. The following scales were used to measure ICF activity participation: the modified Barthel Index (mBI) to assess independence during activities of daily living [27]; the Trunk Control Test (TCT) to assess the trunk stability and control [28]; the Functional Ambulation Classification (FAC) to evaluate basic locomotor skills necessary for functional ambulation [29]; the Time Up and Go test (TUG) to assess mobility, balance, and walking [30]; the 10-meter walking test (10 mwt) to evaluate the walking speed over a short distance [31]; the 6-minute walking test (6 mwt) as a sub-maximal test of aerobic capacity/endurance to assess the distance walked during 6 min [32]. For the participation ICF domain, the Walking Handicap Scale (WHS) was used to assess subject's customary level of walking ability at home and in the community [33].  
Gait analysis was conducted by using the 8-camera SMART-DX motion capture system (BTS Bioengineering, Milano, Italy, 2014) sampling at 200 Hz. The [PERSON] heel protocol, which includes 22 retro-reflective markers, was employed [34], and anthropometric data were collected. Each subject was asked to perform four linear walking trials, barefoot and at a self-selected speed, straight ahead along a level surface that was approximately 5 m long. 3D markers' trajectories were tracked using a frame-by-frame tracking system (Smart Tracker, BTS Bioengineering, Milan, Italy, 2014). Data were processed using 3D reconstruction software (SMART Analyzer, BTS, Milan, Italy, 2014). The mean value of the following spatio-temporal gait parameters were calculated: cadence (step/min)--number of steps in 60 s; gait cycle duration (s)--mean temporal duration of the gait cycle that begins with initial heel contact and ends with the subsequent heel contact of the same foot; mean velocity (m/s); stance time AL (% gait cycle)--percentage of the gait cycle that begins with initial contact and ends at toe off of the affected limb; stance time UL (% gait cycle)--percentage of the gait cycle that begins with initial contact and ends at toe off of the unaffected limb; swing time AL (% gait cycle)--percentage of the gait cycle that begins with the toe off and ends at heel strike of the affected limb; swing time UL (% gait cycle)--percentage of the gait cycle that begins with the toe off and ends at heel strike of the unaffected limb; step length AL (m)--mean longitudinal distance from one foot strike to the next one of the affected limb; step length UL (m)--mean longitudinal distance from one foot strike to the next one of the unaffected limb; and step width (m)--mediolateral distance between the two heels during the double support.