Cost of walking and locomotor impairment

The aim of the present study was to evaluate the importance and the necessi ty of metabolic measurements to quantify locomotor impairment in a clinical context. Oxygen consumption, heart rate, pulmonary ventilation and walking speed were measured during locomotion in 14 normal subjects, used as a con trol group, and 82 patients with different pathologies [hemiparetic, parapa retic, tetraparetic, orthopaedic and paraplegic patients, who walked using a reciprocating gait orthosis (RGO)]. The subjects were characterized on th e basis of a cumulative impairment score (CIS), based on clinical scales co mmonly used to evaluate impairment and disability in locomotion. Appropriat e indices of energy, cardiac and ventilatory costs expressed per metre walk ed, globally called physiological costs, were obtained. It resulted that th e most comfortable speed (MCS) of normal subjects was significantly higher than that of each group of patients. Normal subjects' physiological costs w ere found to be significantly lower than those of patients who needed eithe r a device or the help of a person to walk. All measured parameters correla ted significantly with each other. The MCS was found to be the most correla ted parameter with the CIS (r = 0.8), and therefore it must be considered t he best single measurement, if only one is to be used. Measurements more pr ecise than MCS, such as the physiological costs, may be necessary in clinic al trials. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.