Why Can’t You Make a FIST With Your Wrist Bent? ✊

Bend your wrist all the way down and squeeze a tight fist. Can’t? Your fingers have no muscles in them: they’re puppets. The muscles that close them sit in your forearm and pull long strings (tendons) over your wrist. Bend the wrist down and the strings go slack, so the muscle runs out of pull before the fist is tight. Tip the wrist back and the strings pull tight: the fist clamps shut, and your fingers even curl a little on their own. People whose fingers are paralyzed (after some neck injuries) use exactly that to grab things: wrist back, and the strings close the hand. Therapists call it a tenodesis grip. Could you make a fist? Yes or no?

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#Shorts #Science #HumanBody #Hand #FunFacts

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