The Honda Walking Assist Device (HWAD) powered exoskeleton consists of a lumbar frame with motors on both sides to transfer force to the legs via thigh frames. This training device supports walking, based on the inverted pendulum model. Honda has been conducting research on the device since 1999. The company began lease sales in Japan in 2015; received certification to begin marketing and selling the product in Europe in January 2018; and received pre-market notification from the US Food & Drug Administration in January 2019, although it is not yet available for sale in the United States.
The results of 2 recent studies using the HWAD in 2 different populations—hemiplegic stroke patients and children with cerebral palsy (CP)—were recently published, as follows:
Hemiplegic Stroke Patients: A cohort of 16 stroke patients who suffered hemiplegia (10 on the right, 6 on the left) were recruited to assess the immediate affect the device had on foot and ankle function. Four measures were used: toe-grip strength (TGS), the cross test, and the one maximum step (OMS) width, and the 10-meter walk test, which was performed 3 times: without the device, with the device, and again without the device. The researchers compared walking speed, stride length, and hip joint angle during each iteration.
The results, which were published in The Journal of Physical Therapy Science, indicate that the exoskeleton had a significant impact on hip movement, but minimal effect on walking speed. Those patients who had a greater increase in velocity when using the device had a smaller TGS on the paralyzed side and a decreased OMS on both sides. The authors concluded that the walking measure function of the device was reliable, but that additional research is needed to determine long-term walking improvements.
Children with CP: The goal of this study, which was published in the Journal of NeuroEngineering and Rehabilitation, was to examine gait improvements with use of the HWAD in children with CP. Results were based on 10 children with spastic CP. The children were randomly divided into 2 groups, with Group 1 receiving robot-assisted gait training (RAGT) on the first day, and non-assisted gait training (NAGT) the second day. Group 2 received the opposite. They all performed 30-second walking trials 10 times on a treadmill under both NAGT and RAGT trials. Carryover effect from treadmill walking was examined by having each patient walk 5.5 meters without the device before and after treadmill training.
The results indicate that the patients realized improvements in the maximum hip flexion and extension angle of their affected limb with use of the HWAD. The researchers concluded that an effective gait training protocol in children with CP is to combine HWAD use with treadmill walking.