Hand postures for evaluating trigger finger using leap motion controller

The purpose of this research reported here is to evaluate an abnormal finger motion of trigger finger using Leap Motion Controller to measure finger joint angles by the dot product equation. This sensor is 3D non-contact motion sensor which can detect finger bones. It is estimated positions and directions for fingers and bones. Four postures are used to evaluate an abnormal finger motion that has been used by physical therapist: 1) a flexion of thumb IP joint, 2) neutral position of finger PIP joint, 3) flexion of finger MP Joint, 4) thumb radial abduction. A finger goniometer is used as a reference method to measure the bent fingers' angle. The results showed that an average degree different value of a finger's angle measured by the finger goniometer and this system was 5.73 degrees.