Upper and lower extremity robotic devices for rehabilitation and for studying motor control

The successful motor rehabilitation of stroke, traumatic brain-injured and spinal cord-injured patients requires an intensive and task-specific therapy approach. Budget constraints limit a hand-to-hand therapy approach, so that intelligent machines may offer a solution to promote motor recovery and obtain a better understanding of motor control. This new field of automated or robot-assisted motor rehabilitation has emerged since the 1990s.

This article will present clinically viable devices for upper and lower extremity rehabilitation. The MIT-Manus and the Mirror-Image Motion Enabler robot, which enable unrestricted unilateral or bilateral shoulder and elbow movement, consistently proved superior on the motor impairment level. The ARM guide, which assisted reaching in a straight-line trajectory, and the Bi-Manu-Track, which enabled the bilateral practice of a forearm and wrist movement, are currently being tested. For gait rehabilitation after stroke, the electromechanical gait trainer, GT I, has proved effective compared with treadmill training with body weight support. The Lokomat, consisting of a treadmill and a powered exoskeleton, lessened the therapeutic effort compared with manually assisted treadmill training in spinal cord-injured patients. Future developments will see more degrees of freedom, improved man-machine interaction and the implementation of virtual reality.

Technical possibilities are one aspect, but multi-centre trials and a consideration of the unsubstantiated fears among therapists of being replaced by machines will decide on the successful implementation of this most promising field to the benefit of patients.