Is digital photography an accurate and precise method for measuring range of motion of the hip and knee?

Russell R. Russo, Matthew B. Burn, Sabir K. Ismaily, Brayden J. Gerrie, Shuyang Han, Jerry Alexander, Christopher Lenherr, Philip C. Noble, Joshua D. Harris, Patrick McCulloch

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


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.

Original languageEnglish (US)
Article number29
JournalJournal of Experimental Orthopaedics
Issue number1
StatePublished - Sep 7 2017


  • Digital photography
  • Goniometry
  • Hip
  • Knee
  • Range of motion
  • Visual estimation

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine


Dive into the research topics of 'Is digital photography an accurate and precise method for measuring range of motion of the hip and knee?'. Together they form a unique fingerprint.

Cite this