Smartphone addiction and multisite musculoskeletal pain among parents: The potential mediating role of sleep disturbance and the moderating role of physical activity.

OBJECTIVE: To examine the association between smartphone addiction and multisite musculoskeletal pain burden among parents, and whether this association is mediated by smartphone-related sleep disturbance and moderated by physical activity. METHODS: A total of 1444 parents (447 fathers and 997 mothers) completed a cross-sectional online survey. Smartphone addiction was assessed using the Smartphone Addiction Scale-Short Version (SAS-SV). Total pain burden was assessed by participants rating their pain in each of four predefined areas over the past week (neck, upper back, lumbar region, and wrist/fingers) on a 0-10 numerical rating scale, with the four regional scores summed. Sleep-related variables were daily sleep duration and smartphone-related sleep disturbance. Physical activity was assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF). RESULTS: Smartphone addiction showed a weak but statistically significant positive association with total pain burden (rho = 0.106, p < 0.001) and remained independently associated with pain burden after adjustment for demographic and behavioral factors (B = 0.106, p < 0.001). Smartphone-related sleep disturbance partially mediated this association (indirect effect = 0.016, 95% CI 0.003-0.030). Physical activity moderated the association (B = -0.563, p = 0.015), which was weaker at higher levels of physical activity. Participants with more severe pain profiles had significantly higher smartphone addiction scores. CONCLUSIONS: The findings identify problematic smartphone use as a small-magnitude behavioural correlate of multisite pain burden among parents, independent of the modelled covariates, and best interpreted within a broader behavioural health context encompassing sleep and physical activity rather than through screen time or posture alone.