Facing low pulley cable, sit on seat or bench with legs apart to each side. Grasp stirrup attachment. Place upper arm against inner thigh.
Pull stirrup to front of shoulder until elbow is completely flexed. Lower stirrup until arm is fully extended. Repeat. Continue with opposite arm.
The long head (lateral head) of biceps brachii is activated significantly more than short head (medial head) of biceps brachii since short head enters into active insufficiency as it continues to contract.