The deformity with which this neurological condition first shows itself is the pes cavus. During the period of growth a severely instable cavovarus deformity develops. The author avoids operations on children because the results are usually poor; the basic problem cannot be resolved with surgical measures. He recommends that the affected feet be immobilized by plastic boots until puberty is reached, at which time only minor bone resections for correcting the form of the feet are necessary. In cases of severe cavovarus deformity in early adulthood the author does not use the usual treatment, triple arthrodesis, but operates according to a technique developed by himself: a wedge osteotomy of the Chopart joints is performed to the degree necessary to permit an exact correction of the deformity. In cases of pronounced deformities, the wedge must include the entire navicular bone. After the resection the heel automatically assumes a neutral position and subtalar stability is achieved. In a number of cases the Achilles tendon must be lengthened after wedge resection. To make possible dorsal extension of the operated foot it is necessary to translocate the tendon of tibialis anterior to the base of metatarsus V. If the tibialis anterior muscle is weak or paralysed, we translocate the tendon of tibialis posterior. Instead of running this tendon through the interosseous route, we lead it subcutaneously to the distal part of the forefoot. Preoperative toe deformities are much less pronounced following the operation, and only in rare cases is correction of the first toe necessary.(ABSTRACT TRUNCATED AT 250 WORDS)