Background: Evaluation of joint movements is essential to choose an appropriate rehabilitation protocol for a patient.
Objective: The aim of this study is to suggest an alternative optical technique for measurement of joint angle which is convenient, inexpensive, and can be operated in real time.
Methods: According to the principle of the triangulation method, position sensitive detector (PSD) converts reflected light signals into distance-related voltages. Various parameters were investigated to increase detection range and resolution of joint angle measurements.
Results: The accuracy of the suggested optical sensor was verified by comparing with a commercial goniometer and 3D motion capture system.
Conclusions: This method can be applied to monitor recovery progress for the patient in rehabilitation and sport science.
Keywords: Human joint angle; optical goniometer; position sensitive detector; range of motion; rehabilitation.