Set-up: Grasp an elastic band with a shoulder-width underhand grip. With your upper arms in line with your torso, and your elbows pressed against your sides, bend you forearms to 90 degrees of flexion. Stand with a tight core, a slight bend in the knees, shoulder blades retracted, and a neutral back.
Lift: Keeping your elbow fixed on your side, rotate your forearms from your front to your sides. Return the band to the starting position.
Emphasis: Do not use momentum and keep motion in the rest of the body to a minimum.
Muscle Roles in band pull aparts - waist height, palms-up