Flexor Hallucis Longus: Pain Pattern and Treatment
The flexor hallucis longus is a deep calf muscle whose tendon runs behind the inner ankle and along the sole to the tip of the big toe. It drives push-off in every step and in every rise onto the toes. Its documented pattern is pain under the big toe and the inner ball of the foot, from a trigger point deep in the calf. Dancers and runners know it; the foot examination can miss it.
Attachments and action
Origin: The lower two thirds of the back of the fibula and the interosseous membrane.
Insertion: The base of the distal phalanx of the big toe.
Action: Flexion of the big toe; assists plantar flexion and inversion of the foot; it is the last muscle to push in a stride.
Where the pain is felt: Under the big toe and the inner ball of the foot. Sometimes a short way up the inner sole. Rarely the calf.
Common causes: Dance on pointe or demi-pointe; sprinting and hill running; a thin, flexible sole; a stiff big toe joint that loads the tendon; a long period standing on the toes.
Patients say: "It hurts under my big toe when I push off." "The ball of my foot on the inside aches." Big-toe pain with a clean X-ray.
When to get evaluated: Big-toe pain with redness, heat, and swelling that arrives overnight needs gout assessed. Pain at the big toe joint with a bony bump needs the joint itself assessed. Foot pain with numbness in someone with diabetes needs medical evaluation first.
How this muscle is examined and treated
Examination tests big-toe flexion against resistance, checks the joint, and presses deep through the outer calf for the point that reproduces the pain under the toe. Needling here addresses the muscle deep in the calf from the back, beside the fibula. Assessment and treatment happen in the same visit.
Related conditions
Ankle & Foot PainSports & Performance InjuriesChronic Pain Patterns
This page is educational. It describes muscle referral patterns commonly associated with pain; it does not diagnose your condition. Individual patterns vary. For evaluation of your specific pain, see a licensed clinician. Seek immediate medical care for emergencies. Eugene Baek, L.Ac. · New Jersey License 25MZ00080600