Running myths and realities – What to do with flat feet for running?

You may have been told that your flat feet are the cause of your running injuries. A salesperson may have recommended shoes with arch support, and a professional may have prescribed “corrective” orthotics. You’re wondering if the shape of your feet dooms you to injury. This concern is understandable when you’ve been hearing this for years.

A flat foot has a low arch, meaning there is little curvature under the inner side of the foot. An arch support provides support for this area inside the shoe. An orthotic insole is an insert placed inside the shoe; it can be custom-made or pre-molded. Pronation refers to the inward movement of the foot. The foot’s posture when standing and its movement while running are not the same thing.

Having flat feet does not necessarily mean you’ll get injured. In a study of 246 young military personnel, those with the flattest feet were not the ones who got injured most often. Another study, conducted over 10 weeks with 59 beginner runners, found no clear difference between pronated feet—which turn inward—and neutral feet, which do not have a marked inward or outward tilt. However, the small number of participants limits the certainty of the results.^[13][14]

A review of studies that tracked participants over time found a weak association between an inward-turned foot position and tibial periostitis, a condition characterized by pain along the bone on the front of the leg. A weak association with pain around the patella—the bone at the front of the knee—is also possible, but the evidence is much less certain.^[15]

Achilles tendinopathy affects the tendon that connects the calf to the heel, at the back of the ankle. Not all studies measure the same things. In a study of beginner runners followed for 10 weeks, certain patterns of force distribution under the foot were associated with this injury. The force was directed more toward the outer part of the forefoot and extended less forward^[16]. A 2024 study, on the other hand, compared the standing posture of individuals who had already developed the condition with that of individuals without these injuries. Postures that were more or less turned inward were more common in those with Achilles tendinopathy^[17].

Plantar fasciitis causes pain under the heel, near where the strong band of tissue that supports the bottom of the foot attaches. A study compared 80 people with persistent pain under the heel to 80 people without this pain. A more inward-turned stance was associated with the pain. The odds ratio was 3.7: this measure compares the presence of this gait pattern in the two groups. It does not mean that the future risk of pain is 3.7 times greater^[18]. An association does not prove that the posture caused the pain, nor that altering the arch will make it go away.

For tibial periostitis, foot posture can therefore be part of the evaluation, along with other factors. The review of studies on this posture does not directly test the effectiveness of a shoe or insole in preventing injuries.^[3]

• Foot posture is one of several factors contributing to certain injuries, including tibial periostitis^[15]
• Flat feet that don't cause pain don't automatically require treatment
• Choosing a shoe based solely on arch height did not reduce injuries in military trials. This does not prove that all pronation-control shoes are useless^[19][20]
• The shape of the foot alone is not enough to determine the appropriate treatment: symptoms and difficulties with walking or running also matter

Flat feet should therefore be evaluated based on your symptoms, without automatically assuming a correction is needed. To choose the right shoes, check out our guide to running shoes.

What Should You Do If You Have Flat Feet While Running?

Painless flat feet do not automatically require correction for running. If you’re experiencing pain, have the issue evaluated rather than attributing it solely to your arch. Our guides on Achilles tendinopathy and plantar fasciitis explain the symptoms and treatments specific to these conditions.

Plantar fasciitis can affect people with both low and high arches. A 2004 clinical review describes these two conditions and offers mechanical explanations. This model does not demonstrate that a particular foot shape alone causes the pain.^[4] The 2024 study also found an association between plantar fasciitis and foot positions that are more or less turned inward. The association is stronger for feet that are more turned inward. Foot position was measured while standing; it does not correspond simply to arch height or to foot movement while running.^[17]

You may have had this type of foot for a long time and have been able to cope with it. Flat feet can also develop later in life. See a doctor if your arch has recently collapsed, if only one of your feet is flat, or if you have pain, stiffness, weakness, or numbness. Repeated foot or ankle injuries, difficulty walking, or balance problems are also reasons to see a doctor. Read the NHS’s advice on flat feet.

A pronation-control shoe features elements designed to limit the foot’s inward roll. Its effectiveness varies depending on the model and the individual. In a six-month trial involving 372 recreational runners, 17.6% of participants wearing the pronation-control model sustained an injury, compared with 32.4% of those wearing the standard version. An additional comparison, based on foot posture, suggested a benefit primarily among the 94 runners with pronated feet. This favorable result applies to the specific model tested; it does not guarantee the same effect with all shoes. Read the study by Malisoux and colleagues.

However, the 2022 Cochrane review considers the overall effect of motion-control shoes compared to neutral shoes—which have no specific features to limit pronation—to be highly uncertain. Military trials do not show any advantage to prescribing shoes based solely on arch height. The choice of a shoe can therefore take into account a potential benefit, without making this type of shoe mandatory for all people with flat feet.

Not all repetitive-stress injuries can be explained by pronation. A 2009 clinical review found no definitive link between unusual foot movements and running injuries. This limitation does not negate the more specific associations found in other studies.^[5]

An orthotic device can help relieve symptoms without changing the shape of the foot. A trial involving 135 people with plantar fasciitis compared a ready-made insole, a custom-made orthotic device, and a thin foam insole used as a control. At three months, both types of orthotics modestly improved daily activities: about 8 points higher on a scale of 100. The benefit regarding pain was less clear. At 12 months, there were no longer any clear differences between the groups. This does not mean that all participants had lost the improvement they had gained.^[6]

Another study divided 236 people with plantar fasciitis into five groups. All participants performed stretches for the calf, Achilles tendon, and the underside of the foot. After eight weeks, the groups that added a ready-made insole to their shoes reported improvement more often than the groups that did only stretches or used custom orthotics. Depending on the insole tested, 81 to 95 percent reported improvement, compared to 72 percent with stretching alone and 68 percent with custom orthotics. These results pertain to the insoles studied, when combined with stretching. They do not prove that custom orthotics are always ineffective.^[7]

Where can I learn more about running?

The podcast “Parle-moi de santé” features running tips in its first episode. Alexis Gougeon hosts Blaise Dubois to discuss injury prevention and treatment.

Episode #1: Prevention and treatment of running injuries.

Watch the episode on YouTube:

You can also listen to the episode on Podbean.

Source

• Cowan DN, Jones BH, Robinson JR. Foot morphologic characteristics and risk of exercise-related injury. Archives of family medicine. 1993 Jul 1;2(7):773-7.
• Ramskov D, Jensen ML, Obling K, Nielsen RO, Parner ET, Rasmussen S. No association between q-angle and foot posture with running-related injuries: a 10 week prospective follow-up study. International journal of sports physical therapy. 2013 Aug;8(4):407.
• Neal BS, Griffiths IB, Dowling GJ, et al. Foot posture as a risk factor for lower limb overuse injury: a systematic review and meta-analysis. J Foot Ankle Res. 2014. PubMed
• Bolgla LA, Malone TR. Plantar fasciitis and the windlass mechanism: a biomechanical link to clinical practice. J Athl Train. 2004. PubMed
• Ferber R, Hreljac A, Kendall KD. Suspected Mechanisms in the Cause of Overuse Running Injuries: A Clinical Review. Sports Health. 2009. PubMed
• Landorf KB, Keenan AM, Herbert RD. Effectiveness of foot orthoses in treating plantar fasciitis: a randomized trial. Arch Intern Med. 2006. PubMed
• Pfeffer G, Bacchetti P, Deland J, et al. Comparison of custom and prefabricated orthoses in the initial treatment of proximal plantar fasciitis. Foot Ankle Int. 1999. PubMed