Comparison Between Tai Chi and Balance Training on Spatiotemporal Parameters and Dual-Task Costs During Stair Negotiation in Participants With Knee Osteoarthritis: A Randomized Controlled Trial.

The two groups did not start equal: the Tai Chi group had had knee OA for a mean of 111.21 months compared with 55.11 months in the balance group, and the authors say this imbalance could have affected the results even after they adjusted for it. Sixty-nine people were recruited and 52 were analysed, so a quarter of the sample is missing from the results, and the trial was set up for roughly 62. There was no follow-up after the 12-week programme, so nothing is known about whether any change lasted. Muscle strength and muscle activation were not measured, so the reason for the walking changes is unknown. The authors themselves suggest the counting task may have been too easy to reveal a change in attention, and the two dual-task costs moved together (correlation of 0.89), so they are not independent measures.

The authors declare no conflicts of interest. The supplied text does not say who funded the study or who designed and wrote it up.

Do not conclude that balance training is a better choice than Tai Chi for these patients. The groups did not differ on pain or on any measure of going upstairs, and the one descent measure that favoured balance training, the dual-task cost of cadence, was no longer significant once the change in walking speed was taken into account. The groups also started with very different disease durations, which the authors admit could have shaped the results.