Purpose: To strengthen the muscle groups throughout the leg (primarily in the front of the thigh) and promote balance. Start Position: Facing a mirror with the knee to be exercised bent at 15-20 degrees. Action: Balance on the leg, keeping the knee bent at 15-20 degrees. Parameters: Hold in same position for 30-60 seconds; repeat 6-8 times Tips: Keep the pelvis completely level; squeeze buttocks; keep knee facing directly forward; wear supportive athletic shoes--all of these contribute to proper knee alignment.