What a high arch is
A high arch (pes cavus) is an inner arch that stays high when you stand, so a footprint shows little or none of the middle of the foot. The commonest type, the cavovarus foot, has the heel tipped inwards, the bone behind the big toe angled down, and often clawed toes.
One population study, a footprint survey of 1,846 people aged 16 to 65 in India, found high arches in about 10%. In 277 footballers aged 10 to 40, 30% had high arches, more often at higher levels of play.
Sources 1, 2
What causes it
The two main groups are high arches with no clear cause, called idiopathic, and high arches from a nerve or muscle condition. NHS clinicians describe a high arch as often just a normal variant of foot shape that doesn't normally need treatment.
- Nerve and muscle conditions: Charcot-Marie-Tooth disease, an inherited nerve condition, is the commonest. Others include cerebral palsy, spina bifida and other spinal cord problems, polio and muscular dystrophy, and after a stroke it can affect one foot. In some people the arch increases as muscle weakness worsens; in others it stays the same.
- Other causes: a club foot treated in childhood, an old injury, a cut tendon on the outside of the leg (peroneus longus), and a tight plantar fascia or Achilles tendon.
Sources 1, 3
When a nerve cause is likelyStrong evidence
NHS Lothian's orthopaedic guidance for GPs says a high arch may be the first sign of a developing nerve condition, so any developing high arch should be investigated, particularly if it's only on one side. It asks GPs to refer every one-sided high arch with no known cause.
The NHS lists the signs of Charcot-Marie-Tooth disease: very highly arched feet that can make the ankle unstable (or very flat feet), curled toes, weakness in the feet, ankles and legs, difficulty lifting the foot and a high-stepping walk, numbness, cold feet, thinning of the lower legs and tiredness. Symptoms usually start between 5 and 15, and young children may seem unusually clumsy.
In 148 children with high-arched, heel-in feet on both sides and no known diagnosis, 78% turned out to have Charcot-Marie-Tooth disease, rising to 91% with a family history. In 70 children referred to neurologists, weakness, an unsteady walk, a family history, loss of feeling, muscle thinning and absent ankle reflexes pointed to it. Nerve conduction tests, electromyography (EMG) and genetic tests confirm it.
Sources 3, 4, 5, 6, 7
Foot pain and pressureEmerging evidence
In one study, 60% of 40 people with high arches (with or without a nerve cause) had foot pain, against 23% of 30 people with normal arches. Pressure under the heel and the front of the foot was higher, and it went with the pain. The usual sore spots are under the ball of the foot, under the heel, and painful hard skin, and clawed toes and corns are common.
Sources 8, 1, 3
Ankle sprains: linked in some studies, not in othersMixed evidence
A heel-in high arch puts more load on the outside of the ankle. NHS clinicians say people with high arches may be more likely to have ankle sprains; a review found a heel-in high arch was one of the few foot shapes linked with outer ankle sprains; a study of 277 footballers found high arches among the risk factors for foot and ankle injury; and in a surgical series of 10 people with heel-in high arches and no nerve condition, all had long-standing ankle instability.
But in 116 people having surgery for an unstable ankle, a subtle high arch on X-ray was no commoner than in 105 people without ankle problems. So a high arch may add to the risk, but the evidence is mixed, and the ankle guides cover sprains themselves.
Sources 3, 9, 2, 10, 11
What X-rays can and can't tell youEmerging evidence
A high arch is diagnosed by looking at the foot standing and walking, and nerve tests look for a cause. X-ray judgements of a subtle high arch are unreliable: in the study above, two observers rated 18% and 29% of people without ankle problems as having one. An X-ray report of a cavus foot doesn't by itself mean a problem.
Sources 11, 7
How it usually goes
Without a nerve cause, NHS clinicians treat a high arch as a variant of normal foot shape. With a nerve condition, the arch can increase as muscle weakness worsens, though in some it stays stable. Charcot-Marie-Tooth disease is progressive, but most people keep walking, though older people may need a walking aid. In the Framingham population study, a high-arched foot posture wasn't linked with the foot disorders measured.
Sources 3, 4, 12
Injury risk: not settledMixed evidence
In 449 navy special forces trainees, high arches were one of several risk factors for overuse injuries, and in a survey of 20 high-arched and 20 low-arched runners, the high-arched group reported more ankle, bone and outer-side injuries. But in 927 novice runners in neutral shoes, very high-arched feet had no significant extra injury risk, and a review of 21 cohorts found the evidence on foot posture was mostly about flat feet.
Sources 13, 14, 15, 16