Muscle strength and screen time in children and adolescents undergoing oncological treatment: a cross-sectional study with a correlation analysis

ABSTRACT This study evaluated isometric muscle strength (elbow and knee flexors and extensors), screen time, and their associations with individual and contextual factors in pediatric oncology patients. A portable dynamometer and a questionnaire were used. Muscle strength was below age- and sex-specific norms. Screen time exceeded 4 hours/day in 42% of participants on weekdays and in 31.4% on weekends. Solid tumours are correlated with chemotherapy (r=0.56; p=0.001), and sex correlated negatively with sedentary behavior (r=–0.37; p=0.030), indicating that females reported higher sedentary behavior than males. In the multiple regression model, age was the only independent predictor of muscle strength (β= 10.07, p= 0.001). The observed deficits in muscle strength and high screen time suggest that strategies addressing physical activity and sedentary behavior warrant consideration in pediatric oncology care.