Measuring standing balance in multiple sclerosis: Further progress towards an automatic and reliable method in clinical practice

Abstract Background Balance deficits in multiple sclerosis (MS) are often monitored by means of observer-rated tests. These may provide reliable data, but may also be time-consuming, subject to inter-rater variability, and potentially insensitive to mild fluctuations throughout the clinical course. On the other hand, laboratory assessments are often not available. The Nintendo Wii Balance Board (WBB) may represent a low-cost solution. The purpose of the current study was to examine the methodological quality of WBB data in MS (internal consistency, test-retest reliability), convergent validity with observer-rated tests (Berg Balance Scale, BBS; Timed-Up and Go Test, TUG), and discriminative validity concerning clinical status (Expanded Disability Status Scale, EDSS). Methods Standing balance was assessed with the WBB for 4 min in 63 MS patients at two assessment points, four months apart. Additionally, patients were examined with the BBS, TUG and the EDSS. Results A period of 4 min on the WBB provided data characterized by excellent internal consistency and test-retest reliability. Significant correlations between WBB data and results of the BBS and TUG were obtained after merely 2 min on the board. An EDSS median-split revealed that higher EDSS values (> 3) were associated with significantly increased postural sway on the WBB. Conclusions WBB measures reflecting postural sway are methodologically robust in MS, involving excellent internal consistency and test-retest reliability. They are also characterized by convergent validity with other considerably lengthier observer-rated balance measures (BBS) and sensitive to broader clinical characteristics (EDSS). The WBB may hence represent an effective, easy-to-use monitoring tool for MS patients in clinical practice.