A congenital foot deformity simply means you were born with it. Many of us are born with subtle foot types that predispose us for foot related problems. This can be a flexible flat foot to a rigid high arched foot, called a cavus deformity. Even a tight Achilles tendon can be congenital. Many of us do not even realize we have this underlying foot deformity until later in life when our bodies can no longer accomodate for it due to loss of elasticity.

Cavus feet (high arched feet)

Congenital valgus deformity a.k.a. Flat foot (low arched feet)

Equinus (tight Achilles tendon)