Stroke patients' perception of an inclined sitting support surface: A comparison between visual and proprioceptive inputs

Abstract

The purpose of this study was to examine disorders in the perception of an inclined seat surface of post-stroke hemiplegic patients on presentation of visual or proprioceptive cues. The participants were six hemiplegic patients without parietal lobe lesions, higher order cortical dysfunction or sensory impairment, and six healthy elderly persons as a control group. Two kinds of presentation cue were prepared for an alignment task: an inclined or horizontal bar (V-cue) displayed on a monitor watched by the subjects; and an inclined or horizontal stand (P-cue) placed on a table in front of the subjects on which they placed their arms. The presentation cues were inclined 0, 5 and 10 degrees to the right and left sides, the paretic and unaffected sides of the hemiplegic patients, respectively. The subjects sat on a laterally inclined seat, and were asked to verbally report when the inclination angle of the seat was aligned with the presentation cue; the angle of error was recorded. For the hemiplegic patients under the P-cue condition, when the cue was 10 degrees on the paretic (right) side, the angle of error was significantly increased compared to the unaffected side and both sides of the control group. This result indicates that the hemiplegic patients had a disorder in perception of the body angle on the paretic side. The integration function of postural perception based on visual and proprioceptive information is discussed.