What defines a 'cavus foot deformity'?

A cavus foot deformity is indeed defined by the presence of an abnormally high arch. This condition typically results in an exaggerated curvature of the foot, which can lead to various functional problems. Individuals with this deformity often experience increased pressure on the ball and heel of the foot due to the heightened arch, which can lead to pain and discomfort. Additionally, the high arch can result in instability when walking or standing, as the foot may not effectively absorb shock or provide a stable base for movement.

The other options describe different characteristics of foot structure, but they do not apply to cavus foot. For instance, an abnormally wide structure pertains to a different type of foot shape, while a flat and flexible foot relates more to conditions such as flatfoot or pes planus. Lastly, a structural defect present at birth typically refers to congenital foot deformities, which are distinct from the characteristics defining cavus foot deformity. Understanding the specific nature of cavus feet is crucial for appropriate diagnosis and treatment in pedorthic practice.