Plantar Fasciitis and What the Foot Is Asking For

The description is always the same. First few steps out of bed in the morning, sharp pain under the heel, eases up after a couple of minutes of walking, comes back after sitting through a meeting. People have usually been at it for months by the time they bring it up, and they have usually been rolling the arch on a frozen water bottle and stretching the calf, because that is what the internet says to do.

Start with the name, because the name is misleading and it drives the treatment.

Plantar fasciitis carries the suffix for inflammation. In 2003 a group at Temple reviewed histology from 50 surgical cases of chronic plantar heel pain and found no inflammatory changes in any of the samples (1). What they found instead was myxoid degeneration, fragmentation of the fascia, and vascular changes in the bone marrow. Degeneration, not inflammation. The authors argued the condition should be called plantar fasciosis, which never fully caught on outside clinical literature but reframed the whole problem correctly.

That distinction is not academic pedantry. If the tissue is inflamed, you calm it down. If the tissue is degenerating, calming it down further is the wrong direction, because degenerated collagen does not reorganize without a mechanical signal telling it to. This is the same logic shift that happened in tendon research two decades ago, and the foot lagged behind it.

The trial that made this concrete came out of Denmark in 2015. Forty-eight patients with ultrasound-confirmed plantar fasciitis were randomized to shoe inserts plus daily plantar-specific stretching, or shoe inserts plus high-load progressive strength training performed every other day (2). The strength intervention was almost comically simple: a single-leg heel raise with a towel bunched under the toes to pull them into extension, loaded progressively. At three months the strength group scored 29 points lower on the Foot Function Index, a difference the authors described as a medium effect. By twelve months the groups had converged, which matters and I will come back to it.

Why does the towel under the toes matter mechanically. Extending the toes pulls the plantar fascia taut around the metatarsal heads, which tensions the whole arch structure before you add body weight. That is the windlass mechanism, and putting the tissue under tension while it is loaded is what turns a heel raise into a plantar fascia exercise rather than a calf exercise.

Now the honest reading of that trial. At twelve months, stretching and strength training landed in the same place. The strength group got there faster and felt better sooner, which is not nothing when someone has been limping for eight months. The defensible claim from this trial is a narrow one: loading gets people out of it faster. Anyone selling it harder than that is selling.

What I see in the studio that the trial does not capture is how often the foot is the only thing anyone has looked at. Dorsiflexion restriction at the ankle changes how the foot has to behave during push-off, and someone who cannot get their shin over their foot will find that range somewhere else in the chain. Big toe extension gets ignored almost universally, and it is the joint the windlass mechanism runs through. Hip and calf capacity determine how much of each step the foot has to absorb on its own, which is why the same conversation comes up with people doing volume on the greenbelt and the trails. None of that means the heel pain is coming from any one of those places, because that is not knowable without measuring the person in front of you. It means that treating a foot as an isolated structure is a narrow way to approach a structure that never works in isolation.

Practically, the things worth building are toe extension range and the strength to hold it, calf capacity under slow heavy load, ankle dorsiflexion with control rather than just a wall stretch, and intrinsic foot musculature that most people have never trained deliberately. Spending time out of shoes is part of that, since a lifetime in cushioned soles asks the foot to do progressively less. The ankle mobility foundations work is where I would send someone who wants to start on the dorsiflexion piece, and runners in particular should look at how their mobility work is distributed across the whole lower limb rather than concentrated at the sore spot.

One thing about timelines. Degenerated connective tissue reorganizes slowly, on the order of months, and the Rathleff protocol ran twelve weeks before anyone measured the primary outcome. People quit these at four weeks because the pain has not moved yet, and the expectations around how long tissue change takes are usually the problem rather than the protocol. If you take one operational thing from this piece, take the timeline. If you want the range and capacity measured before you guess at a plan, that is what a session with us is for.

References

1. Lemont H, Ammirati KM, Usen N. Plantar fasciitis: a degenerative process (fasciosis) without inflammation. J Am Podiatr Med Assoc. 2003
2. Rathleff MS, Mølgaard CM, Fredberg U, et al. High-load strength training improves outcome in patients with plantar fasciitis: a randomized controlled trial with 12-month follow-up. Scand J Med Sci Sports. 2015

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