Movement Behavior and Health Outcomes among Sedentary Adults: A Cross-Sectional Study

**Background:** Sedentary behavior is highly prevalent among office workers and is linked to musculoskeletal and cardiometabolic disorders. While prior studies examined postures or physical activity during work or leisure separately, few analyzed both posture and movement across the entire day. This study aimed to comprehensively quantify movement behavior during work and leisure and explore associations with MSD and cardiometabolic health.

**Methods:** Twenty-six office workers (mean age 33.2 ± 9.4 years, mostly female) at UC Berkeley were enrolled. Participants wore a thigh-based activPAL IMU for ≥48 hours to quantify time spent sitting, standing, walking, step count, and number of posture transitions. An Actiheart heart rate monitor and Spacelabs ambulatory blood pressure cuff were worn for 24 hours. MSD was assessed using the 0-10 Numeric Pain Rating Scale across four regions (head/neck/shoulders, upper/lower back, hips/knees/feet/ankles, elbows/hands/wrists); a composite score ≥2 defined the MSD group. Two-tailed independent-sample t-tests compared movement behavior between MSD and NO-MSD groups. Spearman correlations examined relationships between movement metrics, MSD, and cardiometabolic outcomes.

**Key Results:** Participants were highly sedentary, sitting for an average of more than 9 hours per day. The MSD group transitioned significantly more frequently during working hours compared with the NO-MSD group (p<0.05). Moderate positive correlations were found between composite MSD score and number of transitions at work (r=0.4-0.69), while MSD was negatively correlated with daily standing time. Transitions were negatively correlated with BMI and heart rate (both resting and average). Walking time during leisure was positively associated with average pulse pressure. Participants who were more sedentary at work were also more sedentary during leisure and had less sleep duration.

**Clinical Implications:** The findings suggest that frequent posture transitions, rather than simply increasing total standing or walking time, may be a key modifiable behavior for improving both MSD and cardiometabolic outcomes in sedentary office workers. The negative correlation between transitions and both BMI and heart rate supports the potential cardiometabolic benefit of "sitting less and moving more" through frequent posture changes. However, the cross-sectional design precludes causal inference, and the small, relatively active sample (standing 18-24 min/hour at work) limits generalizability. Future longitudinal studies with larger, more diverse cohorts are needed to determine optimal frequency and timing of transitions and to develop predictive models or user-friendly activity indices for interventions.