Gait training using pneumatically actuated robot system

"Locomotor disability is the most commonly reported type of disability. It is defined as a. person's inability to execute distinctive activities associated with moving both himself and. objects, from place to place and such inability resulting from affliction of musculoskeletal. and\/or nervous system. In this category entered the people with paraplegia, quadriplegia,. multiple sclerosis, muscular dystrophy, spinal cord injury, persons affected by stroke, with. Parkinson disease etc.. The number of people with locomotor disabilities is growing permanently as a result of. several factors, such as: population growth, ageing and medical advances that preserve and. prolong life. Worldwide statistics about locomotor disability show that:. - in Australia: 6.8% of the Australian population had a disability related to diseases of the. musculoskeletal system, which is 34% of the persons with any kind of disability;. - in USA: there are more than 700.000 Americans who suffer a stroke each year, making it. the third most frequent cause of death and the leading cause of permanent disability in. the country. 10.000 suffer from traumatic spinal cord injury, and over 250.000 are. disabled by multiple sclerosis per year;. - in Italy: 1.200.000 people have declared the locomotor disabilities.. Rehabilitation is very important part of the therapy plan for patients with locomotor. dysfunctions in the lower extremities. The goal of rehabilitation is to help the patient return. to the highest level of function and independence possible, while improving the overall. quality of life - physically, emotionally, and socially.. Locomotor training in particular, following neurological injury has been shown to have many. therapeutic benefits. Intensive training and exercise may enhance motor recovery or even. restore motor function in people suffering from neurological injuries, such as spinal cord. injury (SCI) and stroke. Repetitive practice strengthens neural connections involved in a motor. task through reinforcement learning, and therefore enables the patients a faster and better relearning. of the locomotion (walking). Practice is most effective when it is task-specific. Thus,. rehabilitation after neurological injury should emphasize repetitive, task-specific practice that. promotes active neuromuscular recruitment in order to maximize motor recovery.. Conventional manual therapy includes specific exercises for strengthening and practicing of. one single movement at time. The more sophisticated therapy which over the years has. established itself as an effective intervention for improving over-ground walking function,. involves practice of stepping on a motorized treadmill with manual assistance and partial. bodyweight support (BWS). This kind of therapy makes use of a suspension system to. provide proper upright posture as well as balance and safety during treadmill walking. This. is accomplished through a harness that removes a controllable portion of the weight from. the legs, redistributing it to the trunk and groin, and in the same time allowing free. movement of the patients’ arms and legs. The movement is provided by a slow moving. treadmill. The treadmill constant rate of movement provides rhythmic input which. reinforces a coordinated reciprocal pattern of movement. Proper coordination is further. assisted by the manual placement of the feet by the therapist. The BWS reduces the. demands on muscles, which may enable the patient to work on improving the coordination. of the movement while gradually increasing the strength of muscles (Miller et al., 2002). The. controlled environment may also increase patient confidence by providing a safe way to. practice walking (Miller et al., 2002). As patients progress, the BWS can be gradually. decreased, challenging the patient to assert more postural control and balance (Miller et al.,. 2002).. This rehabilitation strategy was derived from research showing the effect of suspending. spinalized cats in harnesses over treadmills (Visintin & Barbeau, 1989) From this work with. spinalized cats, it was determined that not only a reciprocal locomotor program can be. generated at a spinal cord level by central pattern generators, but also, this pattern can be. controlled through sensory input. By pulling the stance leg back with the pelvis stabilized in. a harness, the treadmill causes extension to the hip of the weight bearing leg, which triggers. alternation in the reciprocal pattern controlled by the central pattern generator (Grillner,. 1979). Since it was demonstrated by (Barbeau & Rossignol, 1987) that the quality of. locomotion in spinalized cats improved if they were provided a locomotor training. program, it seems reasonable to expect that humans with locomotor disabilities might. benefit from this type of training.. Clinical studies have confirmed that individuals who receive BWS treadmill training. following stroke (Hesse et al., 1994) and spinal cord injury (Wernig et al., 1999). demonstrate improved electromyographic (EMG) activity during locomotion (Visintin et. al., 1998), walk more symmetrically (Hassid et al., 1997), are able to bear more weight on. their legs.. However, manual assistance, during the BWS treadmill training, relies on physiotherapy. procedures which are extremely labour intensive. It is carried out by 2 or 3 physiotherapists,. sitting next to the treadmill, and manually guiding patient’s legs in coordination with a. treadmill. For therapists this training is exhaustive, therefore, training sessions tend to be. short and may limit the full potential of the treatment. Manual assistance also lacks. repeatability and precision. During the manual therapy it is very difficult for even the most. proficient and skilled therapist to provide a proper gait pattern and in that way to maintain. high-quality therapy across a full training session of patients, who require this type of. attention. Also, manually assisted treadmill training lacks objective measures of patient. performance and progress.. A promising solution for assisting patients during rehabilitation process is to design robotic. devices. They may enhance traditional treatment techniques by enabling rehabilitation of all. the joints together, which is more effective that training only one joint at time; they will. provide more precise and repetitive gait trajectory, which was the main problem with the. manual therapy; they could accurately measure and track the patient’s impairments over the. rehabilitation course; they could potentially augment recovery of ambulation in people. following neurological injury by increasing the total duration of training and reducing the. labor-intensive assistance provided by physical therapists. In the general setting of these. robotic systems, a therapist is still responsible for the nonphysical interaction and. observation of the patient by maintaining a supervisory role of the training, while the robot. carries out the actual physical interaction with the patient.. "