Start by standing sideways to a wall slightly over an arms length away. With the straight arm lean against the wall, while keeping your body in a straight line. Lift the wall side leg off the floor and straighten it behind and cross the supporting leg while bending the supporting leg.
Straighten the supporting leg and simultaneously drive the knee of the other leg high and towards the wall. Return to the starting position.
Note. Press your straight arms against the wall during the exercise.