Development of a "Neuro-orthosis" for the control of wrist movements in patients with carpal tunnel syndrome: preliminary results.

Carpal tunnel syndrome (CTS) is a common, painful condition. Treatment is indicated when the symptoms of the disease interferes with the usual daily activities. The use of orthoses is advocated in the treatment of mild and moderate CTS. The rationale for using neutral wrist orthoses lies on the relation of the disease with the increased intracarpal pressure. It was demonstrated that the intracarpal pressure is minimum when the wrist is in neutral position. In spite of their proven therapeutic effects, long-term or improper use of static orthoses may lead to unwanted side effects such as muscle atrophy and discomfort during forceful activities. To overcome the problems caused by a static neutral wrist orthosis, a prototype control system was developed to control the wrist movements via electrical stimulation. At this control system, wrist movements in two planes are controlled by means of electrical stimulation of the antagonistic muscles. The effect of the new control system on hand function and dexterity was compared with those obtained with rigid orthosis and no orthosis.