A Beckman Metabolic cart in use in a study on exercise patients with spinal cord injuries. From: Muszkat R, Yazbek P, Arango CT, Moreira MC, Trombetta IC, Battistella LR. Assessment of functional capacity during gait using a reciprocal propulsion orthosis (ARGO) – a comparative study with a conventional mechanical orthosis. Sao Paolo Medical Journal, 1994, 112(1): page 496.