Sit toward the front edge of a chair. Raise your left leg as high as you can, keeping your knee bent. Under control, slowly, lower your foot. Then, lift the right knee. Try 5 marching steps with left and right counting a one complete marching step. You can add resistance by placing your hands on the top of the thighs as you march and applying light pressure as the leg lifts up. Be sure to stretch your hip flexors after by assuming a modified, stationary lunge position either in a kneeling or standing position.