ABSTRACT
Objective To study the reliability and validity of using sacral markers in evaluating the balance function in standing and walking of stroke patients with hemiplegia.Methods Twenty-one hemiplegic stroke patients were recruited and their baseline mean sway amplitude (MSA) and mean sway velocity (MSV) were measured using sacral markers and center of gravity analysis assuming a segmented body,thegold standard for such analysis.The data were analyzed using Bland-Altman plots to obtain the 95％ limits of agreement (LOA).Results ①Test-retest reliability:The 95％ LOA of the MSA in standing was (-4.42,5.14) on the X axis,(-6.04,4.52)on the Y axis,and (-1.75,1.31) on the Z axis.The MSV in standing was (-0.08,0.09) on the X axis,(-0.10,0.08) on the Y axis and (-0.03,0.02) on the Z axis.The 95％ LOA of the MSA in walking was (-185.74,105.53) on the X axis,(-22.57,2.76) on the Y axis and (4.43,2.76) on the Z axis.The MSV in walking was (-3.10,1.76) on the X axis,(-0.38,0.54) on the Y axis and (-0.07,0.02) on the Z axis.②Validity:The 95％ LOA of the MSA in standing was (-3.62,2.55) on the X axis,(-3.95,3.94) on the Y axis and (-7.35,19.43) on the Z axis.For the MSV in standing it was (-0.06,0.04) on the X axis,(-0.07,0.07) on the Y axis and (-0.12,0.32) on the Z axis.The 95％ LOA of the MSA in walking was (-4.40,4.74) on the X axis,(-17.35,4.14) on the Y axis and (-17.35,4.14) on theZ axis.For the MSV in walking itwas (-0.07,0.08) on the X axis,(-0.29,0.07) on the Y axis and (-0.12,0.18) on the Z axis.The 95％ LOAs of the variables representing their reliability and validity are small enough to be acceptable in clinical application.Conclusions The sacral marker method can be used in assessing the balance of stroke patients.