Validity and Reliability of Nintendo Wii Fit Balance Scores

Context: Interactive gaming systems have the potential to help rehabilitate patients with musculoskeletal conditions. The Nintendo Wii Balance Board, which is part of the Wii Fit game, could be an effective tool to monitor progress during rehabilitation because the board and game can provide objective measures of balance. However, the validity and reliability of Wii Fit balance scores remain unknown. Objective: To determine the concurrent validity of balance scores produced by the Wii Fit game and the intrasession and intersession reliability of Wii Fit balance scores. Design: Descriptive laboratory study. Setting: Sports medicine research laboratory. Patients or Other Participants: Forty-five recreationally active participants (age = 27.0 +/- 9.8 years, height = 170.9 +/- 9.2 cm, mass = 72.4 +/- 11.8 kg) with a heterogeneous history of lower extremity injury. Intervention(s): Participants completed a single-limb stance task on a force plate and the Star Excursion Balance Test (SEBT) during the first test session. Twelve Wii Fit balance activities were completed during 2 test sessions separated by 1 week. Main Outcome Measure(s): Postural sway in the anteroposterior (AP) and mediolateral (ML) directions and the AP, ML, and resultant center-of-pressure (COP) excursions were calculated from the single-limb stance. The normalized reach distance was recorded for the anterior, posteromedial, and posterolateral directions of the SEBT. Wii Fit balance scores that the game software generated also were recorded. Results: All 96 of the calculated correlation coefficients among Wii Fit activity outcomes and established balance outcomes were interpreted as poor (r < 0.50). lntrasession reliability for Wii Fit balance activity scores ranged from good (intraclass correlation coefficient [ICC] = 0.80) to poor (ICC = 0.39), with 8 activities having poor intrasession reliability. Similarly, 11 of the 12 Wii Fit balance activity scores demonstrated poor intersession reliability, with scores ranging from fair (ICC = 0.74) to poor (ICC = 0.29). Conclusions: Wii Fit balance activity scores had poor concurrent validity relative to COP outcomes and SEBT reach distances. In addition, the included Wii Fit balance activity scores generally had poor intrasession and intersession reliability.