From: https://httshirt.com/The rotational arm movement not only reduces stress to the elbows, wrists, and Leslie highly eccentric extra tough and super sarcastic bold since birth shirt. That’s because the pronated position allows greater stretch in the eccentric position whereas the supinated underhand grip allows greater squeezing and contraction during the concentric phase. Additionally these grippers are also very sensitive to asymmetrical pulling mechanics particularly during barbell rows, seated cable rows, and lat pulldowns. If the lifter pulls with one side more than the other it causes the bar to tilt and shift. As a result it helps correct the various asymmetrical pulling aberrations the lifter might be prone too.