One of my characters has hands very different to the ones we're used to.

His fingers can close towards both sides of the hand, meaning that the back of his hand is also a palm and he has a second opposable thumb on the opposite side of our regular thumb (between the little finger and the wrist)

Would this hand setup require major muscular changes? Note that this is a natural trait from his species, not a result of surgery, genetic accidents or magic.

Also, would this different kind of hand be any more functional than regular hands? I tried to design them as a way to make this character more skilled and versatile when manipulating various objects, ranging from a big lance to very small pebbles (and as a way to make the character novel).

  • $\begingroup$ It might help if you told us how you designed your hand. How do the joints look? Do you have a drawing? I'm curious why the muscles are your issue. Anyways, this cannot be answered without details $\endgroup$
    – Raditz_35
    Oct 17, 2017 at 14:03
  • $\begingroup$ Unless his fingers have very fine motoric controls and he can hold objects on both sides of his hand simultaneously, this modification seems to have little evolutionary benefit. $\endgroup$
    – Alexander
    Oct 17, 2017 at 16:53
  • 1
    $\begingroup$ Most people think the muscles for our hands are part of the hand. They're not - our fingers are connected to tendons, and the tendons connect to muscles in our forearms. To make your viable, your character would need a second set of muscles, and both sets would need to have sufficient slack to allow two-way movement. This would lead to huge forearms, and huge hands. $\endgroup$
    – Tim
    Oct 17, 2017 at 20:48

1 Answer 1


Does he have a palm on both sides of his hand? If I go with that he would just have standard omnidirectional joints in the hand, like a cats tail. His hands would either have to be quite large or he would have weak hands. Our hands are strong because they move one way and all the tendons are on the bottom side pulling in. As for the thumb, the same applies.

Weapons and tools would have to be redesigned to accommodate the thumb also.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .