Standing weight-bearing asymmetry in adults with lateropulsion following stroke.

ABSTRACT

BACKGROUND: Weight-bearing asymmetry biasing the non-paretic leg is common following stroke. However, little is known as to how lateropulsion impacts on the weight-bearing patterns adopted in standing by individuals following stroke. RESEARCH QUESTIONS (1) Are there differences in weight-bearing asymmetry patterns observed in standing in people with lateropulsion relative to healthy controls; (2) What is the relationship between weight-bearing asymmetry and clinical measures of lateropulsion and postural function; and (3) Are measures of weight-bearing asymmetry reliable between test occasions. METHODS: Thirty-three individuals with lateropulsion and 35 healthy controls participated in this study. For the participants with lateropulsion, weight-bearing asymmetry during standing tasks (measured using two Wii Balance Boards) and clinical measures of lateropulsion (Burke Lateropulsion Scale) and postural function (Postural Assessment Scale for Stroke) were assessed initially and fortnightly over eight weeks. RESULTS: Individuals with lateropulsion displayed marked weight-bearing asymmetry in standing compared to healthy controls. This asymmetry was predominantly towards their non-paretic leg when standing unsupported, and mixed presentation of weight-bearing asymmetry directions when standing with arm support. No significant correlations were observed between directional weight-bearing asymmetry and the Burke Lateropulsion Scale. A moderate correlation was found between absolute weight-bearing asymmetry for the stand with arm support task and the Postural Assessment Scale for Stroke (r = -0.608). The weight-bearing asymmetry variables for the standing with arm support task were found to be highly reliable between test occasions (ICC 0.915-0.972) and the standard error of measurement was 8.2%-9.3% body weight. SIGNIFICANCE: Individuals with lateropulsion following stroke demonstrate marked and varied patterns of asymmetry in standing. Weight-bearing asymmetry when standing with arm support may be an appropriate outcome measure for use with patients with lower functional abilities, including those with lateropulsion.