Characteristics of a High Arched Foot (Subtle Cavus Foot)
Approximately 20% of the population has a high arch foot shape. A high arch foot is known in medical terms as a “subtle cavus foot.” High arched feet tend to be very stiff through the midfoot, with very little movement through the main midfoot joints. The heel tends to be pointed inward in what is known as a varus position (Figure 1). A high arch foot can be easily identified on examination by looking at the feet head on with the patient standing. If the inside edge of the heel is visible from the front then the individual likely has an inwardly pointed heel (varus heel). This is known as a “peek-a-boo” heel sign (Figure 2).
Unlike in a flatfoot the medial column of a high arch foot is not loose and floppy. Instead, it is quite rigid and often pointed downward (plantar flexed). This part of the foot acts “like a kickstand” to tip the heel in an inward (varus) position. This causes the base of the great toe to take a great deal of force (Figure 3), which can be the cause of a number of problems including sesamoiditis and sesamoid stress fractures.
High Arch Foot Symptoms
A high arched foot predisposes an individual to a variety of symptoms because of the manner in which this type of foot absorbs force. The excess loading on the base of the big toe can predispose people to develop sesamoiditis and sesamoid fractures. Traction forces lead to repetitive loading of the tendons on the outside of the foot and therefore predispose patients to develop peroneal tendonitis. Compression forces are increased on the inside of the ankle, which makes damage to the inside (medial) aspect of the ankle joint more common potentially leading to talar osteochondral injuries or even ankle arthritis. The structure and loading patterns of a high arch foot also make it more susceptible to: ankle sprains; fractures on the outside of the fifth metatarsal (Jones fractures); and pain directly under the great toe (sesamoiditis).
October 15th, 2024