Assessing The Effect Of The Time To Stand Notification On Postural Balance Control

PURPOSE: On average, in the United States, adults spend 7.7 hours per day engaging in prolonged sitting behavior. From a biomechanical perspective, little is known about the effect of prolonged sitting time on physical functions such as postural balance control or center of pressure (COP) displacement. It has been suggested, by the wear time of activity trackers, that the daily recommendation to break prolonged sitting time is to stand or move after sitting for 50 consecutive minutes. The purpose of this study was to understand the effect of the prolonged sitting duration, determined by the “Time to Stand” notification delivered by most activity trackers, on postural balance control measured in healthy young adults. We hypothesize that COP displacement measured in the anterior-posterior and medial-lateral directions during the sit-to-stand task will be significantly increased following 50 minutes of sitting measured in healthy young adults. METHODS: Twenty-four participants (13 male; 11 female) aged 26.5 ± 5.5 (range 21-32) performed 10, 60s trials then sat for 50 consecutive minutes followed by 3, 60s trials. COP excursion, average velocity, and peak velocity were measured in the anterior-posterior and medial-lateral directions. the difference between pre- and post- STS mean values were assessed by paired sample t-tests. This study used a power of 0.8 and alpha of p < 0.0016 to adjust for the inflation of a Type 1 Error due to multiple comparisons (i.e., α 0.05/30 comparisons = p-value 0.0016). RESULTS: There were no significant differences observed for any of the anterior-posterior and medial-lateral COP measures following 50 minutes of quiet sitting. CONCLUSIONS: Findings from this study suggests that for young healthy individuals there was no increased risk of balance loss following an extended session of sitting. To further understand the effect of a break in prolonged sitting duration established by wearable devices, future studies could explore this protocol in other populations such as free-living older adults or evaluate different breaks in times such as intervening at 60 minutes or 90 minutes to establish the minimum amount of time it takes to detect a change in balance loss.