Plantar Fasciitis (Plantar Heel Pain)

What it is

Plantar fasciitis involves the plantar fascia, the thick band of tissue along the sole of the foot from heel to toes. The name suggests inflammation, but a 2023 review reports that tissue samples from people with it showed mainly chronic degenerative changes and not inflammation¹.

The 2023 physical therapy guideline describes pain on the underside of the heel, toward the inner side, that is most noticeable with the first steps after inactivity and worse after prolonged time on your feet, and lists heel pain brought on by a recent increase in weight-bearing activity among the findings that point to it. Heel pain has other causes, so it tells clinicians to look for another diagnosis when symptoms do not fit that picture or do not resolve².

Who gets it and how long it lasts

In a 12-month cohort of 1,206 people, 715 of them runners, runners were no more likely than non-runners to develop plantar fasciitis. Runners who ran more than 25 miles a week were about six times as likely to develop it as people who ran 4 to 12 miles a week. The study recorded weekly distance and not jumps in distance, so it does not show that a sudden increase caused it³.

A 2023 review states that over 80% of patients improved under nonsurgical treatment, and it gives no time frame¹. Chronic plantar heel pain is common and often slow to settle. In 220 people with the chronic form followed for 12 months, rising pain catastrophizing (dwelling on the pain and feeling helpless about it) and rising neuropathic symptoms (nerve-type symptoms such as burning or tingling) were associated with a poorer recovery of pain. That is an association: it does not show that treating either one speeds recovery⁴. Burning or tingling belongs in a clinician's office, and so does a pain that has taken over your thinking.

What the guideline recommends

The 2023 physical therapy guideline's strongest recommendations, graded A, are stretching of both the plantar fascia and the calf muscles (gastrocnemius and soleus) for short- and long-term pain and function, foot taping, rigid or elastic, alongside other treatments for improvement over one to six weeks, manual therapy, and a night splint for one to three months if you consistently have pain with the first step in the morning².

Strengthening carries a weaker grade, C. The 2023 guideline calls for resistance training of the foot and ankle muscles². In a 2015 trial of 48 people with ultrasound-confirmed plantar fasciitis, all given shoe inserts, those assigned to high-load strength training (single-leg heel raises with a towel under the toes, every second day) had less pain and disability at 3 months than those assigned to plantar-specific stretching. At 1, 6 and 12 months there were no differences between groups⁵.

Two things the 2023 guideline advises against as the main plan: orthoses used as the only treatment for short-term pain relief (they may be used alongside other treatments), and therapeutic ultrasound added to stretching². For people who do not improve enough, a 2021 best practice guide built on a systematic review, expert interviews and a survey of people with heel pain offers shockwave therapy, then custom foot orthoses, after the core self-management of taping, stretching and individualized education with footwear advice⁶.

Running with it

The heel sets how much you run, and the treatments above run alongside it:

• A physical therapist's rule for returning runners: pain stays at 3 out of 10 or lower (4 at most) while you run and is stable or improving over the weeks, you stop the run if it climbs above that, and the heel is back to its usual level within 24 hours of finishing. Your first steps the next morning are the check. A limp, or any change in how you move, is a stop. Your clinician may set a different limit. The guide on return to running covers the order of return.
• Replace the running you cut with aerobic work that adds no lower-body impact, at an easy conversational effort, which is zone 2 in a five-zone model.
• Keep the stretching, taping and strengthening going after the pain settles, and fold the foot and calf work into your regular strength routine (see the guide on strength training for runners).
• Rebuild so that no run is much longer than your longest run of the last 30 days. In 5,205 runners followed for 18 months, injuries were more common when a session was more than 10% longer than that⁷. Bring hills and fast running back last, one at a time.

When to see a professional

A diagnosis comes first, because heel pain has other causes, including a heel stress fracture. See a sports-medicine professional if heel pain lasts beyond a couple of weeks, is not improving or you are unsure of the cause. A clinician can confirm the diagnosis and provide the manual therapy, taping and night splint the guideline recommends, and refer on for shockwave if first-line care is not enough. Seek prompt care for heel pain after a specific injury, numbness or tingling, or sharp, localized bone tenderness.