Between January 1982 and December 1986, 101 operations on arthrorisis of the subastragalar joint using calcaneal endorthesis for evolutive pes valgus were carried out in 73 infant (average age 7.4 yrs) patients. The rehabilitative protocol used involved three stages: bed re-education (lst-4th day), re-education stage with partial load (4th-20th day) and total load stage. The operated cases have recently been followed up by evaluating the effectiveness of the surgical correction, controlling the action mechanism of the endorthesis under load and controlling the usefulness of the rehabilitative protocol. The results are reported and special attention is paid to examination of postoperative motor recovery times.