Background: Reliability in measurement of wrist range of motion (ROM) is necessary in clinical examination and evaluation. An infrared position capture device for detection and measurement of hand and finger movements without any physical contact with the device was introduced in 2013. No prior study has evaluated the reliability of this device relative to the measurement of wrist ROM.

Objective: To determine the reliability of the infrared position capture device, and to evaluate its agreement with universal standard goniometer for the measurement of wrist ROM.

Materials and Methods: A comparison of wrist ROM measurements was performed in 33 healthy subjects at the Department of Orthopaedic Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. Candidates with previous wrist injury, wrist surgery, or severe obesity were excluded. Two examiners independently evaluated each participant using both measurement method. The results of both the two measurement methods and the two examiners were compared.

Results: Significant interobserver and intraobserver reliability were found in the measurement of wrist angle using the infrared position capture device and universal standard goniometer. Intraclass correlation coefficient (ICC) comparing infrared position capture device and goniometer was, as follows: flexion 0.86, extension 0.92, radial deviation 0.53, and ulnar deviation 0.76 for examiner 1; and, flexion 0.83, extension 0.92, radial deviation 0.69, and ulnar deviation 0.80 for examiner 2 (range: 0.53-0.92). Infrared position capture device measurements of wrist angle in all 4 positions were very similar to those of universal standard goniometer. The mean difference between methods for measurement of wrist angle ranged from 0.15 to 3.88 degrees.

Conclusions: The infrared position capture device was found to be a reliable tool for measurement of wrist motion. Measurements by infrared position capture device were found to be in agreement with measurements by universal standard goniometer, which is the current standard technique.

Keywords: Infrared position capture device, Leap Motion Controller, goniometer, wrist, reliability, range of motion