29/01/2026
The Flexor Hallucis Longus (FHL): an often-overlooked contributor to plantar fascia pain
When people talk about plantar fascia pain, the focus is usually on the fascia itself.
But one structure that’s frequently overlooked is the flexor hallucis longus (FHL).
The FHL runs from the lower leg, behind the ankle, under the heel, and attaches to the big toe. Functionally, it runs alongside the plantar fascia and helps support the arch during walking, running, and push-off.
Why this matters:
• The FHL helps share load through the foot
• If it’s weak or underperforming, the plantar fascia is forced to take more strain
• Over time, this can contribute to overload and heel sensitivity
In clinic, I often see people with plantar fascia pain who have poor big-toe strength and poor FHL function. When we address this, it can:
✔️ Reduce the load being placed on the plantar fascia
✔️ Improve foot stability during walking and running
✔️ Help calm symptoms by improving load distribution through the foot
That said, this isn’t about replacing plantar fascia rehab.
The plantar fascia still needs to be loaded and strengthened directly.
The key point is this:
If the FHL isn’t doing its job, the plantar fascia is left to work harder than it should.
Rehab works best when both are addressed together, in the right way and at the right stage.
