Trunk-directed airflow reduces mediolateral postural sway during tandem stance

Abstract The postural control system can use sensory cues to regulate body orientation; however, whether noncontact airflow contributes to stance control remains unclear. Here, we show that airflow directed at the trunk alters postural variability during tandem stance. Ten healthy young adults completed three 30 sec trials in each of three conditions (no airflow, continuous airflow, and 60-Hz pulsed airflow) while center-of-pressure (CoP) signals were recorded. Linear mixed-effects model showed lower mediolateral CoP variability during 60-Hz airflow than during no airflow (estimated difference, 1.42 mm; Holm-adjusted p = 0.021), with no significant difference between the two airflow conditions. Rambling-trembling decomposition localized the clearest change to the mediolateral rambling component; its standard deviation and range were lower during 60-Hz airflow than during no airflow. Airflow also shortened the time to the minimum of the CoP velocity-direction correlation curve. These findings indicate that trunk-directed airflow can influence postural control without physical contact and motivate further study of how airflow-induced cutaneous cues are incorporated into multisensory balance control.