Sonja Mensch

114 Chapter 6 these children might feel more sense of control over their environment, which might in turn influence their QoL. However, the knowledge of a relationship between motor function and QoL in this target population is largely lacking. This study explores our hypothesis that a higher motor ability level is related to a higher level of QoL in children with SMD. Specifically, we studied the association between different QoL dimensions and motor abilities in different positions (lying, sitting, standing). In addition, we studied independent associations, controlling for possible confounders i.e. gender, age and GMFCS levels. METHODS Study design and study population This was a cross-sectional study. Children younger than 18 years with SMD who received care in specialised day-care centres were recruited from nine different care organizations for people with intellectual disabilities in the Netherlands. Children with SMD, as included for this study, had a profound intellectual disability (IQ<25), motor abilities comparable with a GMFCS levels IV or V (Palisano et al. 1997) and sensory or other comorbid disorders. Thirty-four physical therapists working in the day-care centres were asked to select one or two of their clients with SMD and 27 agreed to participate. All participating physical therapists had over 10 years of experience working with children with SMD and had to be the therapist of their child with SMD for at least 3 months. They selected 56 children in total who fulfilled the inclusion criteria. The parents or legal representatives of 29 children provided informed consent for participation. Table 1 shows the characteristics of the study sample. Mean age of the children was 9.8 years (range 2-18) and 45% of the children were classified as GMFCS level V.