Original Article Energy expenditure during walking with weight-bearing control (WBC) orthosis in thoracic level of paraplegic patients N Kawashima* ,1 , Y Sone 2 , K Nakazawa 1 , M Akai 1 and H Yano 1 1 Motor Dysfunction Division, Research Institute, National Rehabilitation Center for the Disabled, 4-1 Namiki, Tokorozawa City, Saitama Pref., Japan; 2 Koumei School for Disabled Children, 6-38-27 Matsubatra, Setagaya Ward, Tokyo, Japan Study design: Comparative study of the effectiveness of walking exercise with a newly developed gait orthosis, the weight-bearing control (WBC) orthosis, for thoracic level of paraplegic patients. Objectives: To test its feasibility as a rehabilitation alternative for paraplegic patients, the energy consumption and cost during walking with WBC were calculated and compared with the values of conventional orthoses given in previous reports. Setting: National Rehabilitation Center for the Disabled, Japan. Methods: Four paraplegic patients with traumatic spinal cord injuries ranging from T8 to T12 participated. Experiments were conducted after 3 months of the orthotic gait training with WBC. The cardiorespiratory parameters were continuously measured at rest and during walking with a telemetric device. The steady-state value of the oxygen uptake (V O 2 ), heart rate (HR), the energy consumption (J/kg/s) and energy cost (J/kg/m) were calculated. Results: The average walking speed was 19.072.58m/min. The steady-state value of the V O 2 and HR were 16.0871.93ml/kg and 147.3710.94b/min, respectively. The energy cost during orthotic walking tended to be better than the values of conventional orthoses, whereas the energy consumption was almost similar. Conclusion: WBC enables thoracic level of paraplegic patients to walk at relatively higher speed than conventional orthoses under similar energy expenditure. The special devices equipped with WBC are therefore considered to lead to improvement of the energy cost of walking. The physical intensity presumed by cardiorespiratory responses during walking with WBC is suited to promote their aerobic capacity. Therefore, it is concluded that the WBC orthosis could be an effective alternative in rehabilitation for thoracic level of paraplegic patients. Spinal Cord (2003) 41, 506–510. doi:10.1038/sj.sc.3101494 Keywords: spinal cord injury; orthotic gait; rehabilitation; energy consumption; energy cost; physical intensity Introduction Previous studies have pointed out that the high energy cost has been one of the major problems of the orthotic gait for paraplegic patients. 1–5 Although many devices have been developed to improve this problem to date, it is still difficult to satisfy the requirements of both paraplegic patients and therapists. The futile energy cost should lead to exhaustion in a few minutes of walking. As a consequence, orthotics are frequently abandoned after being used for only a short time in therapeutic phase. 6 Especially for thoracic level of paraplegic patients, a considerable effort of their upper limb and trunk above the paralysis is required during orthotic gait, and this is the main reason of the limitation of the orthotic use. 2,7 One of the major purposes of the orthotic gait for paraplegic patients is the promotion of their health. Since previous studies have suggested the positive effects of walking exercise on secondary disorders, such as the urodynamics 8 and digestive functions, 9 paraplegic pa- tients should make efforts to facilitate their own physical activities in daily life not only with a wheelchair, but also with walking exercise. To this end, the energy cost *Correspondence: N Kawashima, National Rehabilitation Center for the Disabled, 4-1 Namiki, Tokorozawa City, Saitama Pref. 359-8555, Japan Spinal Cord (2003) 41, 506–510 & 2003 International Spinal Cord Society All rights reserved 1362-4393/03 $25.00 www.nature.com/sc