Rationale: In a way, VR-based gaming shows some similarities to Constraint-induced movement therapy. VR games are controlled unimanually or bimanually. When unimanually-controlled games are performed with the affected upper limb, movements of the unaffected hand are completely ineffective. This mimics the principle of forced use. To some degree, also bimanually-controlled games result in a forced use of the affected upper limb.

Additionally, VR could help in the engagement in rehabilitation programs, as virtual environments and gaming increases enjoyment and motivation, and therefore therapy adherence. Accordingly, VR-based gaming may have the potential to improve upper limb functionality in children with CP.

Objective: This study aims to investigate the feasibility of a home-based VR intervention to improve upper limb functionality in children with CP. Sub-objective: The validation of a self-developed upper limb assessment (Upper Limb Reaching Test).

Study population: Children and adolescents with unilateral CP (age 10-18 years old). Intervention: The intervention consists of VR-based rehabilitation with the Oculus Quest device. The training frequency and duration represents 2x15 minutes a day, five days a week, for a total of eight weeks. Therefore, this rehabilitation intervention should represent a total amount of 20 hours of rehabilitation. However, the total dosage is variable as the intervention is self-managed.

Main study parameters/endpoints: Logbook, System Usability Scale, Melbourne Assessment 2, Wall Arm Reaching Test, Elbow and shoulder range of motion.

Inclusion Criteria:

• CP children with a unilateral or severely asymmetric, bilateral spastic movement impairment.
• Age 10-18 years old.
• Manual Ability Classification System (MACS) scores I, II or III.
• House classification of 1, 2 or 3.

Exclusion Criteria:

• Significant (persisting) motion sickness, or any other related adverse event in VR.