Compared to other children, those with disability have additional challenges to being physically active. Prader-Willi Syndrome is a genetic form of childhood obesity that is characterized by hypotonia, growth hormone deficiency, behavioral, and cognitive disability. In children, the low prevalence of this syndrome (1 in 10,000 to 15,000 live births) makes group-based physical activity interventions difficult. In contrast, the home environment presents a natural venue to establish a physical activity routine for this population. This manuscript describes the design of a parent-led physical activity intervention incorporating playground and interactive console-based games to increase physical activity participation in youth with and without Prader-Willi Syndrome.

Purpose: Parents are key role models for their young child’s physical activity (PA) and sedentary behavior. This study examined the relationship between parents and their young child’s PA and sedentary behavior considering whether the parent and child were together (present) or apart. Methods: Parent and child dyads (N = 26) wore accelerometers for 10 days and recorded times when they were present or absent from their young children (parental presence) in an online daily diary. Hourly data for PA and sedentary behavior of both the parent and young child were coded for parental presence. Multilevel modeling was used to predict child behavior (sedentary, light PA, and moderate to vigorous PA) using the respective parent behavior, the presence of the parent, and the interaction between parent behavior and presence. Results: The interaction between presence and parent behavior predicted the respective child behavior (p < .05). Parents’ behavior was positively related to their young child’s behavior when they were together, but the relationship was not present (moderate to vigorous PA) or weaker (sedentary behavior, light PA) when apart. Conclusions: Being active alone was not sufficient for a parent’s PA to relate to their young child’s PA, but rather being active in the presence of their child was important for young child’s PA.

Bone mineral density (BMD) is of concern in Prader-Willi syndrome (PWS). This study compared responses to a physical activity intervention in bone parameters and remodeling markers in youth with PWS (n = 45) and youth with non-syndromic obesity (NSO; n = 66). Measurements occurred at baseline (PRE) and after 24 weeks (POST) of a home-based active games intervention with strengthening and jumping exercises (intervention group = I) or after a no-intervention period (control group = C). Dual x-ray absorptiometry scans of the hip and lumbar spine (L1-L4) determined BMD and bone mineral content (BMC). Bone markers included fasting bone-specific alkaline phosphatase (BAP) and C-terminal telopeptide of type I collagen (CTx). Both I and C groups increased their hip BMD and BMC (p < 0.001). Youth with PWS-I increased their spine BMC from PRE to POST (p < 0.001) but not youth with PWS-C (p = 1.000). Youth with NSO (I and C) increased their spine BMC between PRE and POST (all p < 0.001). Youth with PWS showed lower BAP (108.28 ± 9.19 vs. 139.07 ± 6.41 U/L; p = 0.006) and similar CTx (2.07 ± 0.11 vs.1.84 ± 0.14 ng/dL; p = 0.193) than those with NSO regardless of time. Likely, the novelty of the intervention exercises for those with PWS contributed to gains in spine BMC beyond growth. Bone remodeling markers were unaltered by the intervention.