2022 Volume 37 Issue 3 Pages 319-322
[Purpose] To clarify whether the measurements using the angle value measurement application equipped in iPhone as a standard feature showed the random and systematic error or not, this study compared between the measurements of shoulder joint rotation range of motion by iPhone and those by goniometer. [Participants and Methods] At the shoulder joint, the range of motion of external rotation and that of internal rotation were measured using iPhone and goniometer for 10 healthy male university students. [Results] The measurement by iPhone showed no systematic error. At the shoulder joint external rotation, measurement of range of motion using the iPhone showed that the value of MDC95 was 4.5 degree, while at the shoulder joint internal rotation, the MDC95 was 7.0 degree. [Conclusion] It was suggested that the iPhone application of tilt angle measurement is a tool that can measure the motion range of shoulder joint rotation.