Concave convex rule learning aid

This is a simple tool I designed to help anatomy/physiotherapy/sports rehabilitation students learn the concave-convex rule and the concept of roll and glide in joint mobilisations.

You will need one each of the concave and convex parts and two links. It all snaps together and you shouldn't need any glue. There is enough clearance in the parts to allow it to still move freely even if printed at 50% but it will become quite loose if printed much above 100%.