Open AccessIs digital photography an accurate and precise method for measuring range of motion of the hip and knee?
Author(s) -
Russo Russell R.,
Burn Matthew B.,
Ismaily Sabir K.,
Gerrie Brayden J.,
Han Shuyang,
Alexander Jerry,
Lenherr Christopher,
Noble Philip C.,
Harris Joshua D.,
McCulloch Patrick C.
Publication year - 2017
Publication title -
journal of experimental orthopaedics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 18
ISSN - 2197-1153
DOI - 10.1186/s40634-017-0103-7
Subject(s) - goniometer , range of motion , photography , digital photography , orthodontics , knee joint , medicine , knee flexion , significant difference , mathematics , computer science , surgery , statistics , art , geometry , visual arts
Background Accurate measurements of knee and hip motion are required for management of musculoskeletal pathology. The purpose of this investigation was to compare three techniques for measuring motion at the hip and knee. The authors hypothesized that digital photography would be equivalent in accuracy and show higher precision compared to the other two techniques. Methods Using infrared motion capture analysis as the reference standard, hip flexion/abduction/internal rotation/external rotation and knee flexion/extension were measured using visual estimation, goniometry, and photography on 10 fresh frozen cadavers. These measurements were performed by three physical therapists and three orthopaedic surgeons. Accuracy was defined by the difference from the reference standard, while precision was defined by the proportion of measurements within either 5° or 10°. Analysis of variance (ANOVA), t‐tests, and chi‐squared tests were used. Results Although two statistically significant differences were found in measurement accuracy between the three techniques, neither of these differences met clinical significance (difference of 1.4° for hip abduction and 1.7° for the knee extension). Precision of measurements was significantly higher for digital photography than: (i) visual estimation for hip abduction and knee extension, and (ii) goniometry for knee extension only. Conclusions There was no clinically significant difference in measurement accuracy between the three techniques for hip and knee motion. Digital photography only showed higher precision for two joint motions (hip abduction and knee extension). Overall digital photography shows equivalent accuracy and near‐equivalent precision to visual estimation and goniometry.