The effect of immediate decreasing of weight bearing asymmetry on quiet standing postural control in chronic stroke.

The main patterns characterizing standing posture of hemiparetic patients include: weight-bearing asymmetry (WBA), larger postural sway, asymmetrical contribution of lower limbs to balance control, and increased visual dependency to balance control. The aim of this study was to evaluate the effect of decreasing WBA with the use of a shoe lift, on quiet standing postural control in patients with chronic stroke. Twenty-seven patients participated in this study. Patients completed two tests: 1) quiet standing; and 2) quiet standing while a lift was placed under the non-paretic limb. The following tests were completed on force plates for evaluation: asymmetry of the balance measures (weight bearing, root mean square (RMS) of anterior-posterior (AP) and medial-lateral (ML) center of pressure (COP) velocity), RMS of total AP and ML COP velocity, and AP and ML Romberg quotients. Paired t-tests were used to analyze the data. The mean value of WBA index decreased significantly after using a lift (p < 0.05). However, the changes of the mean value of other postural control parameters were not significant (p > 0.05). The results indicate that there may not be an association between decreased WBA and improved postural control during quiet standing in patients with stroke.