Walking speed on parquetry and carpet after stroke: effect of surface and retest reliability

Abstract

Objective: At the transition stage from rehabilitation to home this study aimed to (1) investigate the effect of floor surface (carpet and parquetry) on walking speed; (2) investigate whether there was a difference between these surfaces as stroke patients voluntarily increased from comfortable to fast pace; (3) investigate whether walking speed on parquetry was a predictor of walking speed on carpet at the two paces; (4) investigate whether walking speed at a comfortable pace was a predictor of walking speed at a fast pace on the two surfaces; and (5) quantify systematic and random error in repeated measurements for fast-paced walking trials. Design: Subjects walked 10 metres at comfortable and fast paces on carpet and parquetry on two consecutive days. Setting: Inpatient rehabilitation centre. Subjects: Twenty-four stroke patients. Main outcome measure: Walking speed. Results: Two-way analysis of variance confirmed that patients walked more slowly on carpet than parquetry (F(1,23) = 5.3, p<0.05) at both paces; the interaction effect was not significant (p>0.05). Walking speed on parquetry was a strong predictor of walking speed on carpet at a comfortable (r= 0.92), and fast pace (r= 0.97). Walking speed at comfortable pace was a moderately strong predictor of walking speed at fast pace on parquetry (r= 0.84),and on carpet (r= 0.88). Random error in repeated measurements was higher when walking fast on carpet (7.21 m/min) and parquetry (8.32 m/min) than when walking at a comfortable pace on carpet (4.63 m/min) and parquetry (3.48 m/min). Systematic error was negligible (p<0.05). Conclusion: Carpet surface was more challenging than parquetry surface, as evidenced by the systematic decrease in walking speed. This may have been due to lack of familiarity. Relative to the wide range of scores in the group, stroke patients showed consistency of walking speed across both surfaces. Likewise, stroke patients retained their relative position in the group as they changed from a comfortable to a fast walking pace. The difference in random error between comfortable and fast-paced trials highlights the need to quantify error in the repeated measurement situation according to specific test conditions.