*3.1. Participants*

A retrospective study was performed, considering sEMG and foot–floor-contact data from 102 volunteer subjects. Volunteers were split into three different groups. H-group was composed of 34 Winters' type I and II hemiplegic children (18 males and 16 females, 6–13 years, age = 7.9 ± 3.0 years, height = 127 ± 18 cm, mass = 27.4 ± 11.0 kg), originally introduced in [4].

C-group was composed of 34 control children (18 males and 16 females, 6–11 years, age = 9.1 ± 1.1, height = 134 ± 9 cm, mass = 32.1 ± 6.9 kg), originally introduced in [35]. A-group was composed of 34 healthy adults (18 males and 16 females, 20–30 years, age = 23.9 ± 1.5 years; height = 174 ± 10 cm; mass = 63.1 ± 12.0 kg), picked up from the populations analyzed in the Movement Analysis Laboratory of Università Politecnica delle Marche, Ancona, Italy and previously introduced in [14] and [36]. Obese subjects were not included in the study. The research was undertaken in compliance with ethical principles of Helsinki Declaration and approved by institutional expert committee. Adult participants

signed informed consent prior the beginning of the test. For children, parental consent and child assent were obtained.
