Shoulder range of motion (ROM) – some online resources

Below are links to two articles on the validity and reliability of smartphone apps to measure ROM:

Validity and reliability of a smartphone application for self-measurement of active shoulder range of motion in a standing position among healthy adults 

Validation of an innovative method of shoulder range-of-motion measurement using a smartphone clinometer application

Below is an article on understanding normal shoulder ROM for information, as it provides the percentages of normal ROM for particular movements:

Understanding the Normal Shoulder Range of Motion