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

Abstract

BackgroundAccurate 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.MethodsUsing 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.ResultsAlthough 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.ConclusionsThere 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.

Orthopedic Surgery and Telemedicine in Times of COVID-19 and Beyond: a Review

“…However, studies have evaluated the precision and reliability of a virtual physical examination and this is done by having the patient go through a series of range of motion and by assessing mobility with a virtual goniometer. [18] Dent et al studied 52 healthy control patients who underwent elbow range-of-motion measurements in person, through teleconference, and still photography. The authors reported high inter-method reliability between teleconference-based goniometry and in-person measurements.…”

The Telemedicine-Based Pediatric Examination of the Back and Lower Limbs: A Narrative Review

“…Digital photography followed by joint angle quantification through an image manipulation software has been shown to have equivalent accuracy and near-equivalent precision compared to visual estimation and goniometry of hip ROM. 33 …”

“…Digital photography followed by joint angle quantification through an image manipulation software has been shown to have equivalent accuracy and nearequivalent precision compared to visual estimation and goniometry of hip ROM. 33 Several smartphone applications display good-toexcellent inter-and intra-rater reliability in the majority of hip movements as well as good-to-excellent validity when compared to a universal goniometer, digital inclinometer, and motion tracking system. [34][35][36][37][38][39][40][41][42] Among the apps currently available for download are "Clinometer + Bubble Level" (Peter Breitling, Plaincode; AppStore, Google Play), "Accurate Compass" (Ngo Na, PVD Apps; AppStore, Google Play), "PT Goniometer" (Mark Busman; AppStore) as well as "Compass" (Apple; AppStore) and "Measure" (Apple; AppStore).…”

“…31 Digital photography for knee flexion/extension with subsequent image analysis has been shown to have equivalent accuracy and near-equivalent precision when compared to universal goniometry and visual estimation. 33 Additionally, several studies have demonstrated that smartphone applications, when compared with a universal goniometer, demonstrate good-to-excellent inter-and intra-rater reliability as well as excellent concurrent validity in knee flexion and extension. 26,34,[53][54][55] Of these, three apps are currently available for download: "Dr. Goniometer" (CDM S.r.L.…”

The Role of Telehealth in Sideline Management of Sports-Related Injuries

“…The accuracy of telehealth tools to determine pain, swelling, range of motion, strength, balance, and gait has been found to be valid, reliable, and feasible [5,11]. Prior studies have shown there is high agreement between in-person measurements and virtual evaluation of range of motion measurements and assessment of function for the shoulder, elbow, hip, and knee [15]. Furthermore, the use of telemedicine for orthopedic evaluation has been shown to be cost-effective, particularly when considering travel time for patients [1,10].…”