Help docs! i'm trying to find out what causes tarsal tunnel syndrome?

Compression on the : Posterior tibial nerve and or its branches. This can be caused by the extensor retinaculum (a band of tissue that overlies the nerves) becomes too tight which can occur when a foot flattens...Engorged blood vessels next to the nerve, any soft tissue mass in the area.....Or things of that nature. They all in some way put pressure in the nerve....

Tarsal tunnel: There can be several causes as stated. Any compression on the nerve is the cause, but an evaluation will reveal the cause or causes. See your podiatrist for that evaluation.