
Highlights
- •Wrist ROM measured with a smartphone agrees strongly with ROM measured by a goniometer.
- •Patients are able to reliably self-measure wrist ROM using a smartphone.
- •The iPhone 5 can accurately measure ROM in wrist-injured population wrist- healthy populations.
- •This in-built feature is free and pre-installed on iPhones and does not require English literacy.
Abstract
Study Design
Cross-sectional cohort.
Introduction
Smartphone gyroscope and goniometer applications have been shown to be a reliable way to measure wrist ROM when used by researchers or trained staff. If wrist-injured patients could reliably measure their own ROM, rehabilitation efforts could be more effectively tailored.
Purpose of the Study
To assess agreement of self-measured ROM by wrist-injured and wrist-healthy study participants using a built-in iPhone 5 level feature as compared to researcher-measured ROM using a universal goniometer (UG).
Methods
Thirty wrist-healthy and 30 wrist-injured subjects self-measured wrist flexion, extension, supination, and pronation ROM using the built-in preinstalled digital level feature on an iPhone 5. Simultaneously a researcher measured ROM with a UG.
Results
Average absolute deviation between the self-measured iPhone 5 level feature and researcher-measured UG ROM was less than 2° for all 4 movements individually and combined was found to be 1.6° for both populations. Intraclass correlation coefficient showed high correlation with values over 0.94 and Bland-Altman plots showed very strong agreement. There was no statistical difference in the ability of wrist-injured and healthy patients to self-measure wrist ROM.
Discussion
Both populations showed very high agreement between their self-measured ROM using the built-in level feature on an iPhone 5 and the researcher-measured ROM using the UG. Both populations were able to use the iPhone self-measurement equally well and the injury status of the subject did not affect the agreement results.
Conclusion
Wrist-healthy and wrist-injured subjects were able to reliably and independently measure ROM using a smartphone level feature.

