Reliability of the Wii balance board for static and dynamic balance assessment in total knee arthroplasty patients.

Purpose: Poor performance in practicing balance tasks is partly caused by the changes in the knee function and balance control activities following total knee arthroplasty (TKA). The purpose of this study was to determine the test-retest reliability of the static and dynamic balance measures using Wii Balance Board (WBB) in patients after TKA.

Design: Thirty-one TKA patients (6 males, 27 females, mean age 55 ± 5.3 years) were involved in the study. They performed four standing balance trials on a WBB on two occasions, with an interval of 3-7 days apart. Double leg stance and functional reach task with opened and closed eyes were assessed in four trials. Extracted center of pressure (COP) measures collected included: mean velocity, medio-lateral displacement, antero-posterior displacement, and area. Intraclass correlation coefficients (ICC), standard error of measure (SEM), minimal detectable change (MDC) and Bland-Altman plots were calculated to show the reliability of COP measures.

Results: ICCs ranged from 0.51 to 0.86 for the four trials indicating moderate-to-good reliability. Just the medio-lateral displacement in double leg open eyes condition showed weak reliability (ICC = 0.29). The highest and lowest ICC values (0.86, 0.29) were obtained for COP medio-lateral displacement in double leg open eyes condition and medio-lateral displacement in double leg close eyes condition measures, respectively. SEM (0.03-5.93) and MDC (0.09-16.45) range scores varied. Bland-Altman plots revealed no significant difference between two trials in both opened and closed eyed conditions, indicating strong agreement between assessments.

Conclusion: These findings suggest that the WBB was a reliable tool for assessing static and dynamic balance tests in TKA patients, making it as a suitable tool for standing balance assessment in clinical settings.