Original article| Volume 95, ISSUE 6, P1156-1161, June 2014

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Clinic-Based Assessment of Weight-Bearing Asymmetry During Squatting in People With Anterior Cruciate Ligament Reconstruction Using Nintendo Wii Balance Boards

Published:March 17, 2014DOI:



      To use low-cost Nintendo Wii Balance Boards (NWBB) to assess weight-bearing asymmetry (WBA) in people who have undergone anterior cruciate ligament reconstruction (ACLR), and to compare their results with a matched control group.


      Quantitative clinical study using a cross-sectional design.


      Orthopedic clinic of a private hospital.


      ACLR participants (n=41; mean age ± SD, 26.0±9.8y; current Cincinnati sports activity level, 75.3±19.8) performed testing in conjunction with their routine 6- or 12-month clinical follow-up, and a control group (n=41) was matched for age, height, body mass, and physical activity level.


      Participants performed double-limb squats while standing on 2 NWBBs, 1 under each foot.

      Main Outcome Measures

      The WBA variables mean mass difference as a percentage of body mass, time favoring a single limb by >5% body mass, absolute symmetry index, and symmetry index relative to the operated or matched control limb were derived. Mann-Whitney U tests were performed to assess between-group differences.


      Significant (P<.05) increases in asymmetry in the ACLR group were found for all outcome measures except symmetry index relative to the operated limb.


      People who have undergone ACLR are likely to possess WBA during squats, and this can be assessed using low-cost NWBBs in a clinical setting. Interestingly, the observed asymmetry was not specific to the surgical limb. Future research is needed to assess the relationship between WBA early in the rehabilitation process and long-term outcomes.


      List of abbreviations:

      ACL (anterior cruciate ligament), ACLR (anterior cruciate ligament reconstruction), MMD (mean mass difference), SI (symmetry index), WBA (weight-bearing asymmetry), WBB (Nintendo Wii Balance Board)
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