lock the knee

Start in an open or closed position.
On 1 put your weight on your right foot and hip, place your left foot at 10:30 about 1 foot away from your center of mass. Use your right hip to counter-balance your left foot for style.
On 2, flex your left calve and bend your left knee so only the ball of your left foot touches the floor while still maintaining your weight on your right foot.
On 3 extend your left calve and lock your left knee so your left foot is flat against the floor. Repeat steps 2 and 3.