Cerebral palsy is a common neurological disorder that is the leading cause of motor disability in children. It causes significant motor impairments, affecting various aspects such as fine and gross motor skills, as well as locomotion, which has a major impact on the quality of life of affected children. It is therefore essential to characterize these functional impairments in order to guide clinical decisions and maximize the motor function of affected children.

Currently, the assessment of motor function is based on physical examinations and functional scales, such as the Gross Motor Function Classification System, which is specifically designed to assess children with CP. However, movement analysis using optoelectronic systems is considered the gold standard for this assessment, even though these systems have notable limitations (expensive installation, time-consuming use, and use only in a clinical environment, making it difficult to assess motor skills in children's everyday lives). In order to establish a comprehensive and personalized functional diagnosis, it is crucial to evaluate other fundamental motor tasks such as running, jumping, object control, and balance tasks. Recently, innovative markerless motion analysis technologies have been developed that allow analysis using smartphones or tablets outside of healthcare facilities. Therefore, developing an application dedicated to motion analysis for children with cerebral palsy that is easy to access and can be used frequently could yield many significant benefits.

Inclusion Criteria:

Common to both groups:

• Obtaining free and informed consent from the child and at least one parent
• Children of all genders aged 6 to 18
• Children affiliated with or beneficiaries of a social security system

For the Cerebral Palsy group:

• Medical diagnosis of CP according to the SCPE (Surveillance of Cerebral Palsy in Europe) definition;
• Unilateral and bilateral impairment;
• Gross Motor Function Classification System (GMFCS) = I to III;
• No major cognitive or visual impairments that limit the performance of motor tasks

For the control group:

- Children free from any disease

Other volunteers included in the protocol (qualitative analysis only (parents and clinicians)):

• Parent(s) of children with CP included in this study;
• Healthcare professionals and researchers involved in monitoring children with CP and/or evaluating the research application within the framework of this study

Exclusion Criteria:

Common to both groups:

• Participants or parent(s) of participants who do not speak French
• Children subject to legal protection measures
• Pregnant or breastfeeding participants

For the Cerebral Palsy group:

• Presence of a cause of neuro-orthopedic disorders other than CP
• Limiting pain
• Surgical procedures performed less than 6 months prior to inclusion in the study
• Any other functional medical intervention that took place 3 months prior to inclusion in the study (e.g., botulinum toxin injections, plaster casts, etc.)
• Medical or surgical interventions planned between visit 1 and visit 2
• Children with a condition other than cerebral palsy that affects their walking ability