Volar plate injuries
A dislocated finger is often just ‘popped’ back in, buddy strapped to the adjoining finger and left to ‘heal.’ Early days you may be able to move it, but progressively it gets more stiff and you lose range 3-4+ weeks later. A dislocation can be associated with a fracture that passes through the joint, or rupture of the volar plate- a cartilage plate that sits on the palm side of the joint and stops the joint from bending backwards i.e. it stabilises it.
Even though you may be able to fully bend the finger the next day, without the proper follow-up the finger then becomes progressively stiffer as it heals until exercises achieve nothing and more aggressive treatment is required. Sometimes a dynamic splint such as in the photo above needs to be individually fabricated to stretch the tight tissues around the joint and get it bending.