Related Experiment Video
Updated: May 15, 2026
Video Movement Analysis Using Smartphones (ViMAS): A Pilot Study
Published on: March 14, 2017
Inter- and intra-observer reliability of a smartphone application for measuring hallux valgus angles
Richard Walter1, Jonathan D Kosy, Richard Cove
1Department of Trauma and Orthopaedics, Torbay Hospital, Lawes Bridge, Torquay TQ2 7AA, UK.
Background:
Measurement of radiological angles can be useful in the planning of the management of patients with hallux valgus. A smartphone application offers an alternative way of measuring these angles in a clinic setting. We compared the reliability (inter- and intra-observer) of this method to the use of PACS.
Methods:
Radiographs of 30 feet from new patients referred with hallux valgus were examined and angles (HVA, IMA, and DMAA) recorded using the smartphone application and PACS.
Results:
The smartphone application provided good inter-observer reliability for HVA and IMA (r=0.93 and r=0.79 respectively). Intra-observer reliability for HVA and IMA was also found to be good (r=0.93-0.97 r=0.82-0.93 respectively). The inter- and intra-observer reliability for using this method to measure DMAA fell below useful levels (r<0.60 in each case).
Conclusions:
This smartphone application provides a reliable method to measure HVA and IMA but we would not recommend it to measure DMAA.
