Background: Patients with complex regional pain syndrome (CRPS) require long-term
treatment. Virtual reality based mirror visual feedback (VR-MVF) can contribute to this treatment. A
personal VR-MVF system has been proposed for treating patients at home. Assessment and understanding
of a patient's condition is required for medical instruction in order to continue home-based
treatment. However, diagnostic questionnaires alone are inadequate for complete assessment of a patient’s
condition. The purpose of this study was to find movement indices for the improvement of CRPS by comparing
hand movements of patients with CRPS to those of normal people.
Method: We compared reaching movements of the wrist and elbow during the VR-MVF treatment task. A personal VRMVF
system was used for collecting data. Reaching movements were defined as movements from 2 seconds before the
grasp of the virtual object to the time at which the object was grasped.
Result: The results showed that healthy participants performed reaching movements with their hand. On the other hand,
the patients with CRPS tended to perform reaching movements by moving their elbow instead of their hand. In addition,
the results showed that the increase in trajectory length of the patients’ hand relative to their elbow may relate to pain reduction.
Conclusion: In accordance with these results, we suggest that focusing on the movements of the hand and the elbow may
be useful for understanding the condition of these patients, and that hand and elbow movements may be used as indices.