## 2 Materials and Methods
### Interventions  
A single 30-min session of each of the interventions was applied to each child in consecutive weeks, one on each week of the month of October 2024. The single-session approach has been previously applied in this population for different interventions [34; 35; 36]. Participants were allowed to maintain their regular therapies throughout the four-week study period. Robot-assisted gait training. For RAGT, the ATLAS 2030 (Marsi Bionics, Madrid, Spain) pediatric exoskeleton owned by the school the children attended was used (Figure 2). It is a portable external device that incorporates patented ARES technology (Adjustable-Rigidity and Embedded Sensor), which allows the mechanical resistance of the device to be adapted to the specific needs of the patient [37]. The exoskeleton structure consists of two legs and a thoracic joint. Each leg is divided into three parts: the upper part, which connects the hip and knee; the lower part, which connects the knee and ankle; and another part, which connects the ankle to a shoe. These parts can be adjusted in length to accommodate the child's size and growth, allowing the exoskeleton to be customized to each patient's measurements. In addition, it has a frame that provides stability and support, allowing the physiotherapist to stand in front of the child and have their hands free to carry out other rehabilitation activities without the need to hold the device from behind while walking [22]. To secure it to the child's body, specific shoes can align the feet, while there are also thigh and shin guards, groin straps, a pelvic belt, and a chest protector to control the trunk which may be used. A head restraint system can also be added if necessary. The device has eight powered joints enabling THKAFO (Trunk-Hip-Knee-Ankle-Foot Orthosis [22]) gait, facilitating flexion and extension movements of the hip, knee, and ankle, as well as hip abduction and adduction. Through these movements, the ATLAS 2030 exoskeleton facilitates both forward and backward walking, offering two modes of use:  
* Automatic or passive mode: In this mode, the device generates a predefined gait pattern based on the kinematics of healthy individuals, which at a set cadence, can be adapted up to 12.6 steps/minute. * Intentional movement or active mode: The exoskeleton halts in the swing phase until the child initiates a minimal muscle contraction to overcome the device's resistance, allowing the step to continue. Resistance levels range across 10 grades, gradually increasing with each level. The device also replicates sit-to-stand and stand-to-sit movements. A tablet interface is used to adjust several parameters, including the speed of sit-to-stand transitions, gait cadence (in passive mode), force thresholds (in active mode), and joint ranges for hip abduction and hip/knee/ankle flexion. The tablet also records the number of steps completed during each session. Figure 2: Atlas 2030 exoskeleton. Available from [[https://www.marsibonics.com/atlas-pediatric-exo/](https://www.marsibonics.com/atlas-pediatric-exo/)]([https://www.marsibonics.com/atlas-pediatric-exo/](https://www.marsibonics.com/atlas-pediatric-exo/)) (accessed on 17 February 2025). The session with the ATLAS 2030 exoskeleton was applied in a 10 m hallway and consisted of three parts: a 2-min warm-up part, in which the participants stood up and walked forward in automatic mode at a cadence of 12.6 steps/minute. Next was the main training part, which lasted approximately 26 min, in which forward walking was trained in intentional movement mode on his or her strength threshold, always ensuring comfort and safety. Resources such as cartoons, body awareness exercises, and games with piles and rings were used to make the session more engaging. The final part or cool-down consisted of a 2-min cool-down performed in automatic mode, walking forward at a cadence of 12.6 steps/minute (Figure 3).