Hand function recovery in chronic stroke with HEXORR robotic training: A case series

Area of Science:

• Neurorehabilitation
• Robotics in Medicine
• Biomechanics

Background:

• Stroke survivors often experience impaired motor function, particularly in hand extension due to spasticity and hypertonia.
• Robotic rehabilitation offers repetitive, activity-based therapy, potentially reducing costs compared to conventional methods.
• Existing robotic systems may struggle to address intrinsic resistance like tone during hand movement assistance.

Purpose of the Study:

• To evaluate the efficacy of a novel Hand Exoskeleton Rehabilitation Robot (HEXORR) system for assisting hand opening in chronic stroke survivors.
• To assess the system's ability to compensate for tone and provide various movement assistance modes.
• To investigate the impact of HEXORR therapy combined with virtual reality on patient motivation and motor recovery.

Main Methods:

• Four chronic stroke subjects underwent 18 sessions of HEXORR therapy.
• The HEXORR system offered modes for movement assistance, free movement, and static force production, with tone compensation.
• Pre- and post-therapy evaluations included robotic range of motion (ROM) measurements, carryover ROM, and clinical assessments (Fugl-Meyer, Box-and-Blocks).

Main Results:

• All subjects demonstrated improved active finger ROM within the robot; most also showed gains in active thumb ROM.
• A majority of the ROM gains achieved within the robot transferred to improvements outside the device.
• Clinical assessments indicated clear improvements in two subjects and mixed results in the other two.

Conclusions:

• HEXORR therapy is a well-received and promising approach for hand rehabilitation after stroke.
• The system effectively assisted hand opening and improved motor function, with gains observed both in and out of the robot.
• HEXORR therapy appears most suitable for patients with mild-to-moderate tone and at least minimal active extension capabilities.