The effects of knee brace wear on perceptual and metabolic variables during horizontal treadmill running

Past research has indicated that runners who wear a Lenox Hill Derotation Brace during treadmill running at 6 mph have an approximate 5% increase in oxygen consumption compared to those who run without the brace. The present study expanded those findings by determining the metabolic and perceptual effects of wearing four commercially available braces while treadmill running at speeds of 6, 7, and 8 mph. The four braces used in this study were the Generation II Poli-Axial Knee Cage, the Orthotech Performer, the CTi Brace, and the Lenox Hill Derotation Brace. Results indicated that the braces caused increases (P less than 0.008) in oxygen consumption, heart rate, and ventilation in the 3% to 8% range compared to running without the brace. Peripheral ratings of perceived exertion were also elevated (P less than 0.001) between 9% and 13%. However, no significant differences were found between the braces. Analysis of covariance indicated the weight of the brace accounted for the increased oxygen consumption during the treadmill runs. We concluded that the braces examined in this study will cause a consistent increase in metabolic cost, which is related to the weight of the braces.