Gait training proves to be an effective approach to help patients with neurological disorders (e.g. stroke, multiple sclerosis) or neurological injuries (e.g. incomplete spinal cord injury) regain functional walking abilities. Intensive
walking training appears to be vital to the activity triggered learning process of the sensorimotor system. For people who will probably never walk again, for instance
due to complete spinal cord injury, assisted gait training diminishes the negative effects resulting from being bound to a wheelchair.
In one of the existing practices, body-weight supported treadmill training (BWSTT),
the patient's body weight is partially supported by an overhead harness while
his/her lower limb movements are assisted by one up to four physiotherapists. The
strenuous physical effort encumbering the therapists and the resulting short training session duration was one of the main reasons for introducing robotics into gait
rehabilitation. The envisaged benefits were:
- Longer and more intensive training sessions, enhancing rehabilitation outcome.
- A reduction of the number of therapists per patient.
- Accurate, quantifiable assistance and/or movements.
- The ability to monitor and steer the patient's rehabilitation process.
Repeatability, accuracy and quantification are features easily associated with robotics. However, a robot operating in close physical contact with an impaired
human requires an approach to robot performance that differs significantly
from the viewpoint of industrial robotics. Accurate repeated motion imposed by a
position controlled robot is considered contraproductive for several reasons: a lack of
adaptable and function specific assistance, a limitation of the learning environment,
reduced motivation and effort by the patient, and a risk of unsafe human-robot interaction. Nowadays, the field of rehabilitation
robotics is increasingly convinced by a human-centered approach in which robot
performance is focused on how the robot physically responds to and interacts with the patient.