SLR - October 2019 - Rikesh A. Patel

The Iphone Measure App Level Function as A Measuring Device for The Weight Bearing Lunge Test in Adults: A Reliability Study

Reference: Banwell HA, Uden H, Marshall N, Altmann C, Williams CM. The Iphone Measure App Level Function as A Measuring Device for The Weight Bearing Lunge Test in Adults: A Reliability Study. J Foot Ankle Res. 2019;12:37. Published 2019 Jul 9. doi:10.1186/s13047-019-0347-9

Scientific Literature Review

Reviewed By: Rikesh A. Patel, DPM
Residency Program: Palmetto General Hospital – Hialeah, FL

Podiatric Relevance: Biomechanical assessment of the podiatric patient is critical to the clinical exam, and often reveals potential etiologies of the patient’s complaint. Rulers and goniometers have been used to assess equinus contractures, however, advances in technology have allowed for cellular devices to include digital inclinometers. Once such device is the iPhone. The iPhone’s measuring application was used in this study to determine their reliability in assessing for ankle range of motion during ankle lunge tests.

Methods: One hundred and sixty-eight measurements of 21 patients were taken performing a lunge test with knee flexed and extended. Two experienced podiatrists conducted all the measuring, both having over eight years of experience. The devices used were measure app on an iPhone 6s (with Ios 7.0>) and inclinometer (which was calibrated to industry standard) and were tested on static flat and angled surfaces for consistency. Participants were preconditioned by holding a static WBL test stance for 30 seconds in knee flexed and extended and then were followed the WBL test protocol consistent with Bennell et al. Short arm of the device was placed against posterior heel one centimeter superior to posterior calcaneal tuberosity and were measured.

Results: The intra-rater reliability between the use of the iPhone and inclinometer were about ICC 0.85, which indicates good reliability. Good validity was demonstrated by a Bland Altman plot of all measures with 90 percent of the plots being in +/- 1.96 SD.

Conclusions: The authors conclude that using the iPhone measure app was easy and a reliable tool for measuring ankle ROM. This allows for a quick and reproducible method of measuring ankle range of motion, in patients with equinus contractures. Since iPhones are used by many, its very practical and easy to integrate in current practice and can be used virtually anywhere, anytime and by anyone including the physician, patient, trainers, etc.  

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