<prompt> what is the Most common cause of tarsal tunnel syndrome ?OsteoahritisAnkylosing spondylitisPsoriatic ahritisRheumatoid ahritis  <response>: Tarsal tunnel syndrome - the syndrome occurs due to compression of tibial nerve within the fibrous osseous tunnel under the flexor retinaculum of ankle joint .This is associated with pain parasthesia in the sole of the foot often worse at night. ref : maheswari 9th ed 