Learn how to do a straight - arm pulldown exercise to improve upper body strength and posture. Find out which muscles it works, what benefits it offers, and how to modify it for your level. Filmed at Exile Gym in Baltimore, MD The straight arm lat pulldown is a variation of the lat pulldown where the arms remain straight throughout the movement. This shifts the tension away from the biceps and isolates the back muscles ... The Straight-Arm Pulldown is an isolation exercise that targets the latissimus dorsi (lats), helping to develop width and definition in the upper back. This exercise is perfect for sculpting a V-shaped back and is an excellent accessory movement for improving your pull-up and row performance.