Set-up: Begin in front of a sturdy door frame. Establish a shoulder width or slightly wider stance and grasp the doorway with one arm so that the wall is perpendicular to your arm.
Lift: Now slowly sit back using your arm to maintain your upright position and to keep you from falling down. Once you have a suitable resistance in your arm, simply pull yourself into the doorframe. Go slowly and do not use momentum.
Repetitions: Perform all prescribed reps on one side, then on the other. This counts as one set.