(1) Background: Our study explores the relationship between expected, perceived, and measured effects of botulinum toxin A (BoNT-A) treatment and saline (placebo) in children and adolescents with cerebral palsy (CP) in the calf muscles of 20 children and adolescents with cerebral palsy (CP), aged 4-15 years, using the Gross Motor Function Classification System (GMFCS) I-II. (2) Methods: A mixed methods parallel database design was used. Quantitative and qualitative data were collected at baseline and four weeks after treatment. The primary quantitative measure was gross energy cost (EC) during walking, obtained from a 5-Minute Walk Test (5MWT), while qualitative semi-structured interviews were performed with each parent and child/adolescent individually. (3) Results: Four weeks after treatment, we did not find any correspondence between expected, measured, and perceived effects. Interestingly, parental perceptions of treatment effects were more consistent than the measured outcomes. We also observed a connection between parental treatment expectations and perceived effects, often related to reduced energy expenditure. Children tended to view their parents as treatment experts and had fewer expectations and perceptions themselves. (4) Conclusions: These findings support the importance of child-centered care, which entails actively listening to children's expectations and perceptions during the treatment process.
Keywords: child-centered care; energy expenditure; expectation; measurement; parallel database design; perception.