SFL client Lin demonstrates the basic Stationary Lunge. Stand with one leg in front of your body and one leg behind. Place the legs as far apart as comfortable. Start the movement by dropping the hips straight down and bending the back knee. The knee of the front leg should stay behind the knee.
Make sure you brace the abdominal and low back muscles to maintain an upright position. Once you have mastered this version of the lunge move to the advanced version of the stationary lunge.
Once you master this version of the lunge, you can start to progress by starting with both feet together and stepping out or lunging forward with one foot and then return to the starting position and repeat with the other foot.