The purpose of the study is to investigate the potential additional benefits of a relatively new physiotherapy method, fascial manipulation, in the rehabilitation of movement difficulties or other problems caused by CP (cerebral palsy). A physiotherapist specialized in fascial manipulation specifically treats the muscle fascia, which plays a central role in the problems associated with CP. Fascial manipulation feels just like a massage but does not hurt. The purpose of the study is to determine how physiotherapeutic rehabilitation methods should be further developed in Finland and elsewhere. Fascial manipulation was originally developed in Italy and is used to treat many musculoskeletal problems. There have been few studies on the effectiveness of fascial manipulation in the context of CP problems. It is important to obtain more research evidence, which is why conducting this study is crucial.