Spring Joint Worm set-up

Hello fellow Unity wizards,

I am building a worm that will be controlled by a ANN that sends signals to two different spring joints allow them to expand and contract like a muscle would.

I'm just trying to set this up at the moment and I've found a work-around but I feel like this approach should work yet i'm getting weird results.

I have a body and tail segment (eventually there will be many body segments) each of the segments are a single cube with two smaller cubes attached on the sides that are fixed to their respective segments. The body segment has a hinge joint that's connected to the tail segment. The hinge joint is purely used as a constraint and will never have code controlling it. The two cubes fixed to the body segment have spring joints connected to the corresponding cubes fixed to the tail segment.

My question is that when I increase the spring on either spring joint, both sides pull in the same direction instead of one spring pulling its respective side then the other pulling the other side. So basically I want an oscillation that allows the worm to wiggle.

I attached a picture so it will be more clear. Thanks for the help