BackgroundPowered exoskeleton can improve the mobility for people with movement deficits by providing mechanical support and facilitate the gait training. This pilot study evaluated the effect of gait training using a newly developed powered lower limb exoskeleton robot for individuals with complete spinal cord injury (SCI).MethodsTwo participants with a complete SCI were recruited for this clinical study. The powered exoskeleton gait training was 8 weeks, 1 h per session, and 2 sessions per week. The evaluation was performed before and after the training for (1) the time taken by the user to don and doff the powered exoskeleton independently, (2) the level of exertion perceived by participants while using the powered exoskeleton, and (3) the mobility performance included the timed up-and-go test, 10-m walk test, and 6-min walk test with the powered exoskeleton. The safety of the powered exoskeleton was evaluated on the basis of injury reports and the incidence of falls or imbalance while using the device.ResultsThe results indicated that the participants were donning and doffing the powered lower limb exoskeleton robot independently with a lower level of exertion and walked faster and farther without any injury or fall incidence when using the powered exoskeleton than when using a knee–ankle–foot orthosis. Bone mineral densities was also increased after the gait training. No adverse effects, such as skin abrasions, or discomfort were reported while using the powered exoskeleton.ConclusionsThe findings demonstrated that individuals with complete SCI used the powered lower limb exoskeleton robot independently without any assistance after 8 weeks of powered exoskeleton gait training.Trial registrationTrial registration: National Taiwan University Hospital.Trial registration number: 201210051RIB.Name of registry: Hui-Fen Mao.URL of registry: Not available.Date of registration: December 12th, 2012.Date of enrolment of the first participant to the trial: January 3rd, 2013.Electronic supplementary materialThe online version of this article (10.1186/s12984-018-0355-1) contains supplementary material, which is available to authorized users.

Design of a new differential-velocity-type compliant joint with two motors is proposed for robotic manipulators. The speed/output torque of the differential-velocity-type joint is synthesized by controlling the differential speeds of a pair of actuators. Descriptions of the design concept, theoretical analysis, and the experiments are presented in this article. The experimental results showed that (1) the stiffness of the differential-velocity-type joint can be regulated by changing the speeds of both motors, (2) the differential-velocity-type joint actually reduced 7.9%-15.7% time compared with the single-drive joint when performing five cycles of reciprocation, and (3) a new design of delta-type robot with differentialvelocity-type driving modules was developed for verification. The experimental results showed that the differential-velocity-type delta robot can perform flexible assembly operations within a 0.028-mm tolerance.