So by distance between tendon and joint this distance is:
1) Vertical off of the joint
or
2) Some distance inline but away from the joint?
In the picture above the tendons appear to be inline and separated by a small distance say 1 inch. But the force applied is parallel to the knuckle which...
So at work I am baffled by a problem to bend a flat plate (3mm thick max) using string where the string is encased in the plate. So naturally I 3d printed some plates and attached a string but found as suspected that the plate would only bend when the string had some angle > than a few degrees...