Definition
High arch (also high instep, pes cavus in medical terminology) is a human foot type in which the sole of the foot is distinctly hollow when bearing weight. That is, there is a fixed plantar flexion of the foot. A high arch is the opposite of a flat foot, and somewhat less common.
Causes
Pes cavus may be hereditary or acquired, and the underlying cause may be neurological, orthopedic or neuromuscular. Pes cavus is sometimes—but not always—connected through Hereditary Motor and Sensory Neuropathy Type 1 (Charcot-Marie-Tooth disease) and Friedreich’s Ataxia; many other cases of pes cavus are natural.
The cause and deforming mechanism underlying pes cavus is complex and not well understood. Factors considered influential in the development of pes cavus include muscle weakness and imbalance in neuromuscular disease, residual effects of congenital clubfoot, post-traumatic bone malformation, contracture of the plantar fascia and shortening of the Achilles tendon.
Among the cases of neuromuscular pes cavus, 50% have been attributed to Charcot-Marie-Tooth disease which is the most common type of inherited neuropathy with an incidence of 1 per 2,500 persons affected. Also known as Hereditary Motor and Sensory Neuropathy (HMSN), it is genetically heterogeneous and usually presents in the first decade of life with delayed motor milestones, distal muscle weakness, clumsiness and frequent falls. By adulthood, Charcot-Marie-Tooth disease can cause painful foot deformities such as pes cavus. Although it is a relatively common disorder affecting the foot and ankle, surprisingly little is known about the distribution of muscle weakness, severity of orthopaedic deformities, or types of foot pain experienced. Currently, there are no cures or effective treatment to halt the progression of any form of Charcot-Marie-Tooth disease.
The development of the cavus foot structure seen in Charcot-Marie-Tooth disease has been previously linked to an imbalance of muscle strength around the foot and ankle. A hypothetical model proposed by various authors describes a relationship whereby weak evertor muscles are overpowered by stronger invertor muscles causing an adducted forefoot and inverted rearfoot. Similarly, weak dorsiflexors are overpowered by stronger plantarflexors causing a plantarflexed first metatarsal and anterior pes cavus.
Pes cavus is also evident in people without neuropathy or other neurological deficit. In the absence of neurological, congenital or traumatic causes of pes cavus, the remaining cases are classified as being ‘idiopathic’, because their aetiology is unknown
Treatment and Prevention
Surgical treatment is only initiated if there is severe pain, as the available operations can be difficult. Otherwise, high arches may be handled with care and proper treatment.
Suggested conservative management of patients with painful pes cavus typically involve strategies to reduce and redistribute plantar pressure loading with the use of foot orthoses and specialised cushioned footwear. Other non-surgical rehabilitation approaches include stretching and strengthening of tight and weak muscles, debridement of plantar callosities, osseous mobilization, chiropractic manipulation of the foot and ankle and strategies to improve balance. There are also numerous surgical approaches described in the literature aimed at correcting the deformity and rebalancing the foot. Surgical procedures fall into three main groups: (1) soft-tissue procedures (e.g. plantar fascia release, Achilles tendon lengthening, tendon transfer); (2) osteotomy (e.g. metatarsal, midfoot or calcaneal); (3) bone-stabilising procedures (e.g. triple arthrodesis)
If the problem persists, consult your foot doctor.