Why is it difficult for your pinky to coil by itself without the ring finger coiling a little bit too?

Answer 1

Hi,
This is to do with the bone structuring of your hand. When you bend your little finger, not only does it involve moving the bones in your little finger, but you'll notice that the bones in your main hand will move as well, especially further up towards the fingers, hence this causes the other fingers to move slightly as well.

However, this isn't the full picture. It is also do with your brain signals sending messages to the muscles - but because the muscles control the bones in your hand they all move.

I hope that helps!

Tom
Biologist

Answer 2

Partly tool use memory, partly anatomy.

When you grasp something with a finger it's usually one of the first two. If the third one is being brought towards the palm it's usually because your bringing all of them in.

The motor centers in your brain minimize unnecessary circuits so you have a hard time trying to control just your pinkee or your ring finger separately you wind up triggering the pathway that activates both.

I wonder if people who use sign language fluently have better individual control over their fingers?

Answer 3

Due to the FLEXOR DIGITORUM TENDONS for fingers #4 and #5 and the FD muscle belly they are attached to working synergistically:

Coiling of fingers is called flexion of the fingers. It is caused by numerous flexor muscles and their tendons that run to the fingers. One muscle is called flexor digitorum and it has 4 tendons that run to each of the fingers #2 -5 (all except the thumb).

Another muscle is called flexor digiti minimi. It is the one that flexes the baby pinkie. So the pinkie has the influence of two muscles and 2 tendons working on it.....one tendon from flexor digiti minimi and one from the four-tendoned flexor digitorum. Thus the pinkie and the ring finger, finger #4, are next to each other and have closely associated muscles and tendons.