Knee braces might enhance balance ability by improving joint stabilization or proprioception. We tested the effects of three different knee braces on single-limb balance. There was a significant decrease in the anteroposterior balance ability when participants wore the brace that was described as the most cumbersome or uncomfortable (p = .04). For the other two braces, there was no difference in single-limb balance ability compared with the no brace condition. Comfort and weight of the knee brace might alter somatosensory inputs, which play an important role in balance ability.