Latissimus, Forearm, Trapezius, Shoulders, Core, Back
With an underhand, shoulder-width grip, hang from a pull-up bar, then elevate your feet by bending at the hips so that your legs are now perpendicular to your torso. Your abs should be isometrically contracted to hold this body position. This will be your starting position.
Contract your biceps and lats to pull your chin over the bar in a smooth motion, then release to descend just short of full arm extension.