Reactive Joints are a chassis option for 60-75 ton mecha that incorporate use of spring loaded pusher plates to better propel missile weapons (Missile damage + 6) and accelerate limb movement (dodge 7, 3% increased chance for double damage). They don't function so well in extreme cold environments where the springs can get frozen solid, however (ice vulnerable 5%)!
The Reactive Joints are a basic modular unit and aren't a big deal to install and will cost you 900 Ferrite, 228 Bioptics and 43 Crystal. The pusher plates they employ use a clever combination of helical, torsion and compression springs which effectively behave as a mechanical analog to the systems of ligaments and tendons one would find in a living animal.
Submitted by Mycobacter #712744