"In the context of limited accessibility to prolonged and efficient rehabilitation programs based on physical activity, this study aims to develop a home program for children with chronic diseases affecting physical health (including cerebral palsy, obesity, and neuromuscular diseases). The French company EzyGain has designed a compact treadmill equipped with sensors and a safety system, which communicates with a tablet application and a virtual reality headset to support at-home rehabilitation. This study seeks to advance the development of this solution into a prolonged and progressive training program, tailored to positively impact children's health. Future users, including children, their parents, and therapists, will be at the heart of the development process. A qualitative methodology will be employed, incorporating focus groups and a series of user experience (UX) questionnaires. The research hypothesis is that user feedbacks will enable the development of an appropriate solution that meets their specific needs and ensures high adoption rates of the device.

This study is the first step before assessing the impact of the solution in these 3 groups of children (with cerebral palsy, obesity and neuromuscular disease)."

"Visit 1: Children, accompanied by one of their parents, will test the treadmill and the associated rehabilitation games on a tablet and in immersive virtual reality in its current version, and UX questionnaires will be administered.

Visit 2: Children, parents, and therapists, in groups of 6 to 8, will participate in focus groups during which they will express their opinions regarding the solution they tested in Visit 1 and discuss areas for improvement.

(several monthsare dedicated to the developpement of the solution by the society, based on the children, parents and therapists' feedbacks)

Visit 3: Children, accompanied by one of their parents, will test the treadmill and the associated rehabilitation games on a tablet and in immersive virtual reality in its new version, and UX questionnaires will be administered."

"Inclusion Criteria for the children:

• aged between 8 and 18 years old
• capable of walking during 5 minutes on a treadmill with or without walking aid, and with or without body weight support
• diagnosis of one the following pathology: bilateral cerebral palsy, obesity, spinal muscular amiotrophy type 3, Duchenne, congenital myopathy, Charcot Marie Tooth
• Gross Motor Function Classification System (GMFCS) I to III for the children with cerebral palsy
• IMC superior to the centile IOTF-30 for the children with obesity
• Functionnal level of 2 to 6 on the Walton scale, or 3 to 7 on the Vignos scale for the children with neuromuscular disease

Inclusion Criteria for the parents:

- parent of an eligible child

Inclusion Criteria for the therapists:

- Therapist of at least one eligible child

Inclusion Criteria for all:

• Able to express oneself and respond to a questionnaire in French
• Formulate their non-opposition to participate in the research

Exclusion Criteria:

• Deprived of liberty by judicial or administrative decision
• Subject to a legal protection measure"

Patients and parents from the active lists of medical doctors of the structures involved in the project. Therapists of the structures involved in the project.