Effectiveness of an innovative hip energy storage walking orthosis for improving paraplegic walking: A pilot randomized controlled study

Background The high energy cost of paraplegic walking using a reciprocating gait orthosis (RGO) is attributed to limited hip motion and excessive upper limb loading for support. To address the limitation, we designed the hip energy storage walking orthosis (HESWO) which uses a spring assembly on the pelvic shell to store energy from the movements of the healthy upper limbs and flexion-extension of the lumbar spine and hip and returns this energy to lift the pelvis and lower limb to assist with the swing and stance components of a stride. Our aim was to evaluate gait and energy cost indices for the HESWO compared to the RGO in patients with paraplegia. Methods The cross-over design was used in the pilot study. Twelve patients with a complete T4-L5 chronic spinal cord injury underwent gait training using the HESWO and RGO. Gait performance (continuous walking distance, as well as the maximum and comfortable walking speeds) and energy expenditure (at a walking speed of 3.3 m/min on a treadmill) were measured at the end of the 4-week training session. Results Compared to the RGO, the HESWO increased continuous walking distance by 24.7% (P < 0.05), maximum walking speed by 20.4% (P < 0.05) and the comfortable walking speed by 15.3% (P < 0.05), as well as decreasing energy expenditure by 13.9% (P < 0.05). Conclusion Our preliminary results provide support for the use of the HESWO as an alternative support for paraplegic walking.