Fig. 150.—Pes Cavus in association with Pes Equinus, the result of Poliomyelitis.
Fig. 151.—Radiogram of Foot of adult, showing the changes in the bones in Pes Cavus.
Flat-Foot—Pes Planus and Pes Valgus
Flat-foot or splay-foot is that deformity in which there is loss of the arch, and the foot tends to be pronated and abducted. The term pes planus is applicable when there is merely loss of the arch; pes valgus when the foot is pronated and the sole looks laterally. Of all deformities of the foot, flat-foot is the one for which advice is most frequently sought; it is also a common complication of other disabilities of the foot and of the lower extremity. It is usually bilateral, and is about twice as common in the male as in the female. Various types are met with; they are known according to their cause, as static, congenital, traumatic, paralytic, rachitic, rheumatic, arthritic, gonorrhœal, and tabetic.
Static or Adolescent Flat-foot.—This, by far the most common and important variety ([Fig. 152]), generally develops between the ages of fourteen and twenty. It is called static because the essential factor in its production is a disproportion between the weight of the body and the supporting power of the arch of the foot.
