Flat Feet, High Arches and Bunions: When They Matter and When They Don't

Foot Shape Versus Foot Symptoms

Flat feet, high arches and bunions are often described as problems in themselves, and some people are told their feet will inevitably cause pain elsewhere. The evidence suggests a more measured view. Feet vary widely, and many people with flat or high-arched feet, or with a bunion, have no pain and no functional limitation. The shape of a foot is one piece of information; whether it hurts, limits activity or changes how a person loads their leg is what makes it clinically relevant.

Arch Type and Overuse Injury

A systematic review and meta-analysis of prospective cohort studies examined static foot posture as a risk factor for lower-limb overuse injury (Neal et al., 2014). It found strong evidence that a pronated (flatter) foot posture is a risk factor for medial tibial stress syndrome, commonly called shin splints, and very limited evidence for patellofemoral pain, with small effect sizes in both cases. No relationship was found between pronated posture and other injuries studied, including foot and ankle injury and bone stress reactions. The authors concluded that foot posture is best seen as one part of a broader risk profile rather than a stand-alone cause.

The runner data point the same way. In a cohort of 927 novice runners wearing a neutral shoe, neither pronated nor supinated (higher-arched) feet showed a significantly higher cumulative injury risk than neutral feet, although the numbers with highly pronated or highly supinated feet were small (Nielsen et al., 2014). A flat or high-arched foot may modestly shift risk for some conditions, but it does not predict pain on its own.

Bunions Are Common

Hallux valgus, the medical term for a bunion, is very common. A systematic review pooled prevalence at about 23% of adults aged 18 to 65 and about 36% of those over 65, with higher rates in women than in men, while noting that studies used varied diagnostic methods (Nix et al., 2010). Being common is not the same as being painful, and the size of the deformity on an X-ray does not reliably indicate how much a bunion will hurt.

Where bunions do cause pain, non-surgical care is usually the first step and focuses on managing symptoms rather than reversing the deformity. A Cochrane review of surgery found no trials against placebo or sham surgery, and low-certainty evidence that surgery may reduce pain more than no treatment or non-surgical care at 12 months, from a single trial (Dias et al., 2024). In other words, surgery can be reasonable for persistent, disabling pain, but the evidence for it is still limited.

When They Matter

Foot posture and bunions are worth attention when they come with pain, difficulty fitting shoes, reduced walking tolerance, or a pattern of recurring injury in the foot, shin or knee. In those situations, an assessment of strength, load history and footwear is more informative than a label based on the shape of the arch. Without symptoms, there is little evidence that an unusual foot shape needs correcting.