Sign "strong" by flexing in your arms towards your chest, fists closed. "Stronger" is more with mind, body and heart. STRONGERIFY!

Stronger is the new BLACK.

American Sign Language (ASL) is a visual language. With signing, the brain processes linguistic information through the eyes. The shape, placement, and movement of the hands, as well as facial expressions and body movements, all play important parts in conveying information. (NAD.ORG)