The effects of various visual conditions on trunk control during ambulation in chronic post stroke patients

Downward gazing is commonly observed among patients after a stroke during standing or walking as they struggle to maintain equilibrium. In this study, we aimed to evaluate the effects of fixed gazing and downward gazing on trunk control ability during gait. Sixteen subjects after a stroke (age: 51.3±4.9years) and seven healthy subjects (age: 65.1±3.4years) participated in this study. Participants walked 10m at a comfortable speed while they faced forward (no gaze point), gazed forward (with a fixed gaze point), gazed downward, and gazed downward while concealing their legs. Trunk acceleration was measured using tri-axial accelerometers attached to the back of the upper (C7 spinous process) and lower (L3 spinous process) trunk. The coefficient of attenuation (CoA) of acceleration at the trunk was computed to assess trunk control ability. Results in the stroke group showed that the CoA during fixed-point and downward gazing was better than that while facing forward with no gaze point (p<0.001). In the stroke group, the CoA during gazing downward with their legs concealed was worse than that during downward gazing. Our findings indicate that patients after a stroke might use visual information for reducing their neck oscillation (C7) during fixed-point and downward gazing. Our results indicate that the visual information during downward gazing might work the same as during fixed-point gazing.