PWS is a genetic disorder that affects the endocrine, musculoskeletal, and respiratory systems, resulting in altered hypothalamic function, reduced growth hormone production, hypotonia, altered bone development, and reduced tidal volume. Major diagnostic criteria include characteristic facial features, global developmental delay, hyperphagia, hypotonia, and rapid weight gain at ages 1-6 years leading to central obesity. Evaluation of patients with PWS involves assessing functional movement patterns and mobility, including gait, balance, and posture, as well as the overall nature and efficiency of movement. Musculoskeletal impairments associated with PWS include general weakness, hypotonia, and hypoactivity. Scoliosis and hip dysplasia are often part of the clinical presentation of patients with PWS. Physical therapy is aimed at increasing physical activity levels and physical conditioning, with goals that include improving movement ability and efficiency, increasing muscle strength, and reducing the impact of obesity associated with PWS.