THE INFLUENCE OF THE RECIPROCAL CABLE LINKAGE IN THE ADVANCED RECIPROCATING GAIT ORTHOSIS ON PARAPLEGIC GAIT PERFORMANCE

A wide variety of mechanical orthoses is available to provide ambulati on to paraplegic patients. Evaluation of energy cost during walking in each of these devices has been acknowledged as an important topic in this field of research. In order to investigate the benefits of a ball istic swing on gait performance in the Advanced Reciprocating Gait Ort hosis (ARGO) a study was conducted in which the ARGO was compared with an orthosis with freely swinging legs. This Non Reciprocally linked O rthosis (NRO) was obtained by removing the reciprocal linkage in the s ubjects' own ARGOs. Subsequently, flexion/extension limits were mounte d to permit adjustment of stride length. Six male paraplegic subjects with lesions ranging from T4 to T12 were included in the study. A sing le case experimental design (B-A-B-A) was conducted in order to improv e internal validity. Biomechanical and physiological parameters were a ssessed and the subjects' preference for either ARGO or NRO was determ ined. It was found that large inter-individual differences produced in sufficient evidence in this study to draw general conclusions about di fference in energy expenditure between both orthoses. However, individ ual analysis of the results showed a reduction of oxygen cost (range: 4%-14%) in the NRO in T9 and T12 lesions, while oxygen cost in subject s with T4 lesions increased markedly (22% and 40%). It is concluded th at patients with low level lesions could benefit in terms of oxygen lo st from removing the reciprocal cable linkage in the ARGO. However, on ly one subject preferred the NRO for walking, whereas none of the subj ect chose the NRO for use in daily living activities. Removal of the r eciprocal cable linkage in the ARGO may not be desirable for these pat ients.