Plantar fasciopathy
Evidence: moderate
High-load strength training has the best support and gives faster early relief than stretching alone, but it rests on a single small RCT. Most other measures, from orthoses to night splints, are comfort aids with modest or mixed evidence. The one near-certainty is the timescale: recovery runs over months.
Not medical advice
This is a general knowledge base, not medical or dietary advice. If you are injured, unwell or weighing up a supplement or a change to your diet, speak to a doctor, physiotherapist or registered dietitian who knows your situation.
Plantar fasciopathy is pain under the heel, at the point where the plantar fascia attaches to the heel bone. The older name ‘plantar fasciitis’ implies inflammation, but the tissue change is mainly degenerative rather than inflammatory, which is why ‘fasciopathy’ is the more accurate term and why rest and anti-inflammatories alone tend to disappoint (Rathleff et al. 2015). It is one of the most common causes of foot pain in runners and sits alongside the other load-related complaints on the common overuse injuries page.
How it presents
The classic story is sharp pain under the medial heel that is worst with the first steps of the morning, or after sitting for a while (Rathleff et al. 2015). The fascia stiffens during rest, and loading it cold after a period off the feet provokes the pain. It then eases as the foot warms up over the first few minutes of walking, only to return with prolonged standing or running later in the day. That pattern, start-up pain that settles then comes back under sustained load, is the most useful diagnostic clue.
Risk factors
The best-characterised risk factors come from a matched case-control study that found three independent associations: reduced ankle dorsiflexion, which was the strongest factor; obesity, with a body-mass index over 30 kg/m²; and spending the majority of the working day on the feet (Riddle et al. 2003). A tight calf and limited ankle dorsiflexion increase the tensile load the fascia has to absorb at each step, which fits the load-based model. Later work has found the dorsiflexion link less consistent than that early study suggested, so it is a plausible target rather than a proven cause (Riddle et al. 2003). For runners specifically, the usual trigger is a spike in training load, the same load-faster-than-tissue-tolerates story behind most running injuries.
The best-supported treatment: high-load strength training
Because the problem is load-related tissue change, loading the tissue helps. An RCT compared high-load progressive strength training against plantar-fascia stretching, both groups also using shoe inserts. The strength protocol was slow, heavy heel raises performed with a towel bunched under the toes to dorsiflex the toe joints and so stretch and load the fascia, done every other day with a rising load. That group had lower pain and better function at three months than the stretching group; outcomes converged by twelve months (Rathleff et al. 2015). So the gain from heavy loading is faster early relief rather than a different end point, which is still worth having given how long this injury drags on. The logic mirrors tendinopathy rehabilitation: a degenerative, load-related tissue responds to graded heavy loading.
Stretching and load management
Stretching still has a place. Both plantar-fascia-specific stretching and calf stretching are reasonable, and the trial above used stretching as its comparator with real if slower improvement (Rathleff et al. 2015). Plantar-fascia-specific stretching, pulling the toes back to put the fascia on tension, addresses the morning start-up pain directly. Alongside any exercise, the core move is load management: cut running volume to a level the heel tolerates, keep it there while you build capacity, then rebuild gradually rather than resting completely and returning to full mileage in one step (see return to running).
Orthoses, night splints and taping
Several passive aids are popular and earn a caveat each.
Foot orthoses and insoles give modest medium-term pain relief of uncertain clinical importance (Whittaker et al. 2018), and only weak evidence supports them for preventing running injuries (Bonanno et al. 2017). They are a reasonable comfort aid for some runners, not a routine fix. See insoles and orthotics.
Orthotics: a comfort aid, not a cure
Foot orthoses can ease heel-pain symptoms for some people, but the effect is modest (Whittaker et al. 2018) and the evidence for routine or preventive use is weak (Bonanno et al. 2017). Try the cheaper, better-evidenced loading and load-management route first.
Night splints, which hold the ankle in dorsiflexion overnight to keep the fascia on a light stretch, and low-dye taping, which supports the arch to offload the fascia in the short term, are both used. Their supporting evidence is thinner than that for loading, so they are adjuncts that may help some people with symptoms rather than the core treatment (Rathleff et al. 2015).
It takes months, and usually resolves
The hardest part to accept is the timescale. Plantar fasciopathy is usually self-limiting, but slow: meaningful change takes weeks, and in the trial above the two groups only converged at a year (Rathleff et al. 2015). The degenerative tissue adapts slowly, so there is no quick fix. Setting that expectation early, and resisting the urge to abandon the programme because it feels slow, is part of the treatment. Foot strike and arch mechanics are sometimes blamed; see biomechanics and gait for why gait tinkering is rarely the lever it is sold as, and the basics for where effort is better spent.