Rehabilitation robotics : stimulating restoration of arm function after stroke

Abstract

Stroke is a major cause of permanent disability, due to neurological damage in the brain. As a consequence, arm and hand function may be compromised: 60% of stroke patients experiences serious limitations in daily life due to reduced arm and hand function. To minimize such limitations, patients receive rehabilitation care. Optimal rehabilitation treatment should include several key aspects: active initiation and execution of movement, high intensity of training and application of functional exercises. Technological innovations enable development of interventions that specifically address these key aspects. A promising innovation is the use of rehabilitation robots in addition to conventional therapy, since robotic devices can apply forces to the arm of a person in a smart way: imposing passive movements, assisting active movements, or resisting active movements. In her PhD research, Gerdienke Prange investigated in which way rehabilitation robotics can provide a valuable addition to conventional rehabilitation care for people with limitations in arm function after stroke. Both rehabilitation robotics and the sole application of one of its basic features, gravity compensation (or arm support), have the ability to improve arm movement ability after stroke. Gravity compensation facilitates and enhances reaching movements by direct application using a custom designed, smart gravity compensating device, Freebal. This is translated to improvement of unsupported reaching movements after a longer term application of gravity compensation as training intervention, involving mainly an improved ability to activate prime mover muscles at the elbow and shoulder. The potential of current robot-aided therapy and gravity compensation training to improve arm movement ability after stroke is comparable to conventional therapy, and to each other. Considering implementation in clinical practice, the relatively simple, low-tech application of gravity compensation is more suitable than complex, high-tech devices. As advantage over conventional therapy, gravity compensation training, using a low-tech device in combination with interactive games, allows automation of therapy, with one therapist supervising multiple patients training at the same time. This offers the possibility to increase productivity of the healthcare system and reduce costs.