Clinic-based assessment of weight-bearing asymmetry during squatting in people with anterior cruciate ligament reconstruction using nintendo Wii balance boards

Objective: 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.

Design: Quantitative clinical study using a cross-sectional design.

Setting: Orthopedic clinic of a private hospital.

Participants: 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.

Interventions: 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.

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

Conclusions: 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.