Energy expenditure during gait using the walkabout and isocentric reciprocal gait orthoses in persons with paraplegia

Abstract

Objective: To compare the energy expenditure during walking using the Walkabout Orthosis (WO) and the Isocentric Reciprocal Gait Orthosis (IRGO) in persons with paraplegia. Design: A randomized cross-over design. Patients: Ten individuals with complete T9–12 paraplegia. Interventions: Subjects were trained to walk using the WO and the IRGO0 with elbow crutches. Main Outcome Measures: Subjects' energy expenditures during walking using each orthosis over three different terrains—flat tile, flat carpet, and 4° uphill ramp—were compared. Data collected included expired ventilation (L/min), heart rate (beats/ min), speed of walking (m/min), oxygen uptake (VO 2; L/min and mL/kg/min), oxygen cost (O 2 cost; mL/kg/m), and Physical Cost Index (PCI; beats/m). Subjects walked at a self-selected pace. Results: Subjects walked significantly slower with the WO than with the IRGO, regardless of the surface ( p < .05). The average speed of walking ranged from 5.2 ± 1.3 for the WO on the tiled surface to 11.5 ± 2.3m/min for the IRGO on the carpeted surface. Despite marked differences in self-selected walking speeds between the two orthoses, there were no differences in either heart rate or VO 2 among orthoses or surfaces. However, the O 2 cost of gait was significantly greater for the WO (range, 3.95 to 4.91mL/kg/m) compared with the IRGO (range, 1.6 to 1.8mL/kg/m). Likewise, the PCI was significantly greater using the WO (range, 8.4 to 10.3beats/m) than the IRGO (range, 4.3 to 7.Obeats/m). Conclusions: This study shows that the metabolic demands of walking with the WO are greater than walking with the IRGO in individuals with T9–12 paraplegia.