I'm 31 years old, where can i find a gait pllate? the only ones i can find are pediatric.

Podiatrist: See a podiatrist. They can have one made, but it would be unusual to need at age 31.

Because.....: Gait plates are not frequently prescribed for the adult population. More rare than common. Having said that, I have prescribed them on ocaasion to an adult. These devices are generally custom made, simiiar to an orthotic. Any podiatrist should be able to help you out.