The Effect of Using Brace in Three Different Knee Flexion Angles on Frequency of Muscular Activity During Running in People With Genu Varus

Genu valgus malalignment is associated with altered lower limb muscular activities during running. The study aimed to evaluate the effect of using a brace in three different knee flexion angles on the frequency of muscular activity during running in people with genu varus.

The statistical sample of this study consisted of 30 soccer students. Fifteen persons with genu varus and 15 healthy persons were selected to participate in this study. The electrical activity of the muscles, including medial gastrocnemius, tibialis anterior, vastus medialis, rectus femoris, vastus lateralis, biceps femoris, and semitendinosus, were recorded by electromyography system during running with four brace conditions (without a brace, knee brace at 15˚, 30˚, and 60˚ knee flexion).

The results showed that the main effect of “brace” on the frequency spectrum of the biceps femoris during the loading phase was increased statistically. During the loading phase, the most significant median frequency of the biceps femoris was running with a brace with 30˚ knee flexion. The main effect of “brace” on the frequency spectrum of semitendinosus during the push-off phase was statistically significant. The lowest value of semitendinosus muscle was during running with a brace with 15˚ knee flexion.

The most significant effect of a knee flexor brace is on the frequency content of biceps femoris and semitendinosus muscles with a mount at 30˚ knee flexion. This may be due to the passive support role of the brace and possibly could prevent biceps femoris and semitendinosus injuries.