<Originals> Effects of walking speed and load condition on muscle activity of lower extremities during normal human gait

The purpose of this study was to determine the effects of walking speed and load during normal human gait on the muscle activity of the lower extremities. Nine healthy subjects with a mean age of 24.3years, participated in this study. Electromyographic activity while walking was measured in the gluteus maximus, gluteus medius, rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semimembranosus, and gastrocnemius. Treadmill walking was performed at two speeds (2km/h and 4km/h), and three loading conditions (no-load, and loads of 2% and 4% of body weight in the form of bilateral ankle weights). Muscle activity of all muscles at a walking speed of 4km/h was significantly greater than that at 2km/h. A significant difference was also demonstrated for various loads on muscle activities of the gluteus medius, biceps femoris, semimembranosus, and gastrocnemius. These findings suggest that the ankle weights using while walking had less effect on the gluteus maximus and quadriceps femoris