[Illustration: FIG. 155.--Bilateral Pes Valgus and Hallux Valgus in a girl æt. 15, the result of Anterior Poliomyelitis.] In paralytic valgus the medial border of the foot is depressed and convex towards the sole, and although the foot can readily be restored to the normal position by manipulation, it at once resumes the valgus attitude. The leg is wasted, the skin is cold and livid, and the ankle is flail-like. The treatment consists in reinforcing the paralysed tibial muscles by attaching the peronei, or a strip of the tendo Achillis, to the scaphoid, or in bringing about an ankylosis of the joints above and in front of the talus. #Traumatic flat-foot# is that form which results directly from injury. It is most often due to a fall from a height on to the feet; the ligaments supporting the arch are ruptured, and the bones are displaced, either at the time of the injury or later when the patient gets out of bed. The arch can only be restored by a wedge-resection of the tarsus. Loss of the arch may follow as a result of walking on the everted foot after injuries about the ankle, especially a badly united Pott's fracture; the foot may be displaced laterally and pronated, the sole looking laterally. This variety is very unsightly and disabling; it is treated by supra-malleolar osteotomy of the tibia and fibula. #Other Forms of Flat-foot.#--Flat-foot is sometimes met with in rickety children, in association with knock-knee or curvature of the bones of the leg, and is treated on the same lines as other rickety deformities. It may follow upon an attack of acute rheumatism or upon diseases in the region of the ankle and tarsus, such as gonorrhœa, arthritis deformans, tuberculosis, and Charcot's disease; the gonorrhœal flat-foot is extremely resistant to treatment. There is a congenital form in which the sole is convex and the dorsum concave, the result of the persistence of an abnormal attitude of the fœtus _in utero_. Lastly, there is a racial variety, chiefly met with in the negro and in Jews, which is inherited and developmental, and which, although unsightly, is rarely a cause of disability. #Pes Transverso-planus.#--Lange describes under this head a sinking or flattening of the anterior arch formed by the heads of the metatarsal bones, of which normally only the heads of the first and fifth rest on the ground. In this condition all may be on the same level or the arch is actually convex towards the sole. It may coexist along with the common form of flat-foot, or it may be associated with the neuralgic pain known as metatarsalgia.