Validity and Reliability of iPhone Application in Active Internal Rotation Measurement of Shoulder in Patients With Shoulder Pain

Eighteen patients with shoulder pain who applied to the Physical Medicine and Rehabilitation, shoulder subspecialty outpatient clinic who agreed to participate in the study and 18 volunteers who had not experienced shoulder pain before enrolled in the study. Participant age range was determined as 40-70 years.

The IHandy® app is a free app with a visual display similar to that of the digital inclinometer in terms of digital size. In this study, due to its prevalence in the literature and its use in clinics, manual goniometer (gold standard) was chosen to be compared with this iPhone application.

The participants were asked to lie on the bed in supine position with shoulder to be measured at the edge of the bed. The measured shoulder was positioned at 90 degrees abduction, 90 degrees elbow flexion and forearm at neutral position. The participant was asked to bring the wrist closer to the bed in the direction of the little finger, and was measured at the angle that the shoulder could not move without lifting the arm. In the measurement made with the application, the phone was held parallel to the ulna and the value displayed on the screen was recorded. The participant were asked to repeat the movement if his/her shoulder lift up of bed, straightened his/her elbow, or did anything that would disrupt her movement pattern.

Each measurement was repeated 3 times and after 2 weeks the control measurements were made by repeating 3 times.

Measurements were conducted separately in different cabinets without seeing each other for each participant by 1 physical medicine and rehabilitation specialist and 1 physiotherapist. The measurements were recorded in separate locations until all participants were completed.