Use of Tendon Vibration and Mirror for the Improvement of Upper Limb Function and Pain Reduction After Stroke

Upper limb paralysis following stroke is a very common problem. Only 30% of stroke patients who suffer from upper limb paresis experience a full recovery of function. There is a need for the development of more efficient rehabilitation methods for the improvement of the paralysed upper limb function.

It has been shown that the use of mirror therapy after a stroke induces the activation of motor, sensory and associative regions in the affected hemisphere and is associated with an improvement in the function of the affected limb. Mirror therapy is a treatment modality in which the affected arm is hidden from the patient's sight; the patient is instructed to watch the reflection of his healthy hand on a mirror while he performs movements with his healthy hand and tries to move simultaneously his affected hand. This induces the illusion that his affected hand moves well.

It has also been shown that applying vibration to a muscle tendon at frequencies between 50-100 Hz induces an illusion of elongation of the vibrated muscle, if visual feedback is prevented. For instance, vibrating the triceps will induce a strong illusion of elbow flexion.

In the present study the investigators will couple the use of a mirror with the application of vibration to tendons, in order to obtain a multisensorial and strong illusion of movement in the paralyzed limb.

The study hypothesis is that the administration of mirror therapy together with vibration will induce the activation of multiple motor, sensory and associative areas in the affected brain hemisphere, resulting in improvement of the affected upper limb function, compared to the administration of mirror therapy alone or sham therapy.