Set-up: Find a pull-up bar and assume a wide overhand grip. Use a wider grip to achieve a straighter off arm and increase difficulty, or a narrow grip as you build strength and command of the movement.
Movement: Bracing through your core, lift yourself toward one side of the bar until your chin is over the bar. The arm on your opposite side should begin to straighten. Cue yourself to pull your chest to the bar to ensure full height. Descend all the way to full extension as this will engage more of the shoulder stabilizers and muscle mass of the back - this will help in maintaining health in the shoulder girdle.
Optional weighting: A weight belt will allow for external loading to make the exercise more difficult.