An accessory posterior ankle muscle belly is observed, located deep to the flexor retinaculum and lateral to the flexor hallucis longus muscle. The corresponding tendon attaches below the sustentaculum tali and the tendon sheath contains a small amount of fluid. The posterior tibial neurovascular bundle and both the flexor hallucis longus and accessory muscle appear normal.
In addition, there is a marked thickening of the central band enthesis of the plantar fascia with a partial-thickness tear.
No other abnormalities.