Cavus foot (high-arched foot)

What is a cavus foot?

A cavus foot (also called pes cavus, or a high-arched foot) has an unusually high arch that stays high when you stand. In many cases the heel also tilts inward and the first metatarsal, the long bone behind the big toe, points downward. The foot normally rests on a tripod of the heel, the ball of the big toe and the ball of the little toe. In a cavus foot the big toe side sits too low, which tilts the foot and overloads the other two points.^[2,5]

A cavus foot is different from a flat foot, and it is not the same as “Charcot foot” (see Charcot foot), which is a separate condition of the bones and joints in people with nerve damage. Charcot-Marie-Tooth disease, one possible cause of a cavus foot, is an inherited nerve condition.

Symptoms

• a high arch that you can see when you stand
• hammertoes or claw toes, and calluses under the ball and heel or on the outer edge of the foot
• pain when standing or walking, often in the heel, ball or outer side of the foot
• an unstable foot, with a heel tilting inward, which can lead to ankle sprains
• in some people, a weak foot that drags (foot drop)^[1]

What causes a cavus foot?

The most common causes in adults are neurologic conditions, such as Charcot-Marie-Tooth disease, cerebral palsy, spina bifida, polio, muscular dystrophy and stroke, which upset the balance of strength between the muscles of the foot. A cavus foot can also be inherited as a structural trait, and it can follow an injury or a leftover clubfoot deformity.^[1,3,5] Muscle imbalance is the main mechanism: stronger muscles overpower weaker ones and pull the foot into the high-arched position.^[2]

Problems that can go along with it

Because the outer edge of the foot takes extra load, a cavus foot can lead to ankle instability, inflammation of the peroneal tendons, stress fractures, and, over time, arthritis in the overloaded joints.^[5] See chronic ankle instability, peroneal tendon injuries and plantar fasciitis. Toe deformities and forefoot pain, such as hammertoes and plantar plate tears, are also common.

How it’s evaluated

The evaluation reviews your family history, the arch and heel position when you stand and walk, muscle strength, the way your shoes wear, and X-rays. A referral to a neurologist can be helpful when a nerve condition is suspected.^[1] A key part of the examination is the Coleman block test, which shows whether the tilt of the heel comes mostly from the forefoot or from the heel itself, and that guides the plan.^[5] The underlying cause needs to be understood before treatment is planned.^[2] X-ray and ultrasound are available on site at our practice; see foot and ankle imaging.

Non-surgical care

Treatment starts without surgery. Options include custom orthotics that cushion and stabilize the foot, footwear with a wider heel and higher top for stability, and braces for ankle stability or foot drop.^[1] Conservative treatment is always used first, with surgery reserved for cases that don’t respond.^[3] Stretching and strengthening, guided by a physical therapist, are often added.

When surgery is considered

Surgery is considered when non-surgical care doesn’t relieve pain and improve stability, or to compensate for weakness.^[1] The goal is to correct the muscle imbalance. The operation can include releasing tight tissue, transferring tendons, cutting and realigning bones (osteotomies), and, in the most severe cases, fusing joints.^[3,4] Most plans combine soft-tissue and bone procedures, and they are tailored to the person’s deformity.^[4] When a nerve condition keeps changing the foot, early attention to tendon balance is emphasized in the literature, because the deformity can otherwise become fixed and harder to treat.^[5]

For the operations, recovery and risks, see cavus foot surgery.

When to seek care

Consider an evaluation if a high arch is causing pain, calluses or repeated ankle sprains, if your foot is becoming higher-arched over time, or if you notice weakness or dragging of the foot.