Fig. 1

Flow diagram of the study. The baseline phase will encompass randomly between 5 to 8 assessment sessions. Comprehensive outcome measurements will be conducted during the first and last appointment. For the other occasions, only a short assessment of selective control, muscle strength and motor control of the joint showing involuntary co-movements or co-activations is planned. During the intervention phase, participants will receive 10 sessions of game-based SVMC training. The short assessments (only SVMC and strength) will be continued after each treatment session, and the full assessment battery will be repeated at the end of the intervention as well as 12 weeks after completion. The study will run concurrently to the participant’s individual rehabilitation at the Swiss Children’s Rehab. Abbreviations: SVMC: selective voluntary motor control, SVMC mini-assessment: short game-based assessment to repeatedly measure selective control, SCALE: selective control assessment of the lower extremity, SCUES: selective control of the upper extremity scale, TMS: transcranial magnetic stimulation, MMT: manual muscle test, MAS: modified Ashworth scale, HAT: Hypertonia Assessment Tool