Flexor Hallucis Longus Tendinitis: [Causes, Symptoms & Best Treatment] Flexor Hallucis Longus Tendinitis can cause pain in 3 areas: #1 is the big toe, #2 is the back of the ankle and #3 is the bottom of the arch.   Flexor Hallucis Longus Tendinitis Overview: Flexor Hallucis Longus Tendinitis: The flexor hallucis longus muscle tendon … Read more