The principles and practice of hip guidance articulations∗

Introduction Many complete paraplegic patients, ranging from adults with traumatic lesions to children with spina bifida cystica, are given a variety of orthoses in an attempt to produce locomotion on an empirical basis with little or no understanding of the mechanical principles involved. Not surprisingly large numbers fail to achieve this and even greater numbers abandon the exhausting, slow ambulation produced after long rehabilitation, in favour of the wheelchair. Swivel walking devices (Motloch and Elliot, 1966) were used for the first time for this type of patient in Shrewsbury in 1967 (Edbrooke, 1970). The fundamental mechanics had been worked out by Spielrein in 1963 for an amelic case and were confirmed for these patients by Rose and Henshaw (1972). Despite the undoubted advantages of this type of apparatus and in particular the fact that it can be used in time coincident with developmental stages and leaves the hands free, the dynamic cosmesis is always accepted by the patients or parents. A B Fig. I . With the patient hyperextended (A) or flexed (B) at swing leg/hip, the geometry of the leg is the same, and when lifted from the ground it will swing forward under the influence of gravity.