The development of a new orthosis (neuro-orthosis) for patients with carpal tunnel syndrome: its effect on the function and strength of the hand.

Static wrist orthoses (SWOs) are used in the treatment of carpal tunnel syndrome (CTS) with some drawbacks. As an alternate approach to SWOs, an active closed-loop wrist control strategy based on the principles of functional electrical stimulation was proposed to limit wrist movements. The purpose of the study was to determine whether the proposed 'neuro-orthosis' (NeO) system resulted in less restriction in the hand compared to clinically accepted custom-made SWOs while limiting the wrist movements. A case-control study was designed to determine the specific effects of the system on patients with CTS. A total of 24 right-handed female volunteers (12: CTS, 12: healthy) participated in the study. Function, dexterity, and strengths were measured under three different testing conditions: without orthosis, with SWO, and with the NeO system. Maximum angles in one subtest while the NeO system was on and off and general discomfort levels in SWO and NeO test conditions were recorded. The NeO system resulted in less restriction with respect to SWO and provided considerable angular limitation compared to placebo. It was concluded that the proposed prototype control system can be a good candidate to limit the wrist movements in place of SWOs with a better degree of freedom in patients with CTS.