In evaluating any new method of ROM measurement, accuracy is crucial, but the method must also remain easily accessible to patients and clinicians. Recent advances in smartphone photography have introduced a new ubiquitous platform for photo goniometry. With nearly two-thirds of Americans owning a smartphone, 6 the cameras on these devices would easily allow patients to remotely send images and videos to physicians for clinical evaluation. Smartphone photography has the potential to facilitate telemedicine, increasing patient access and simplifying long-term follow-up. However, smartphone goniometry has yet to be validated for ROM measurements in the digits. In the replicate study parts A, 2x2x10 (trial x goniometer x rater) and 2x10 (goniometer x rater) repeated measures ANOVAs were run for each position-joint and trial-position–joint data set, respectively, to assess the main effects and interactions of goniometer, trial, and rater. The sphericity assumption was tested by using Mauchly’s test with appropriate epsilon adjustments. For further reflection of intra-goniometer (i.e., intra-rater ) reliability, proportions of clinically non-meaningful ≤ 5-degree differences between the measurements obtained with the same tool in the 2 trials were calculated for each rater. Similarly, for the assessment of inter-goniometer reliability, proportions of ≤ 5-degree differences between measurements of the same rater with different instruments within the same trial were found. The observed proportions of the ≤ 5-degree differences were tested against proportion of 0.95 for statistical significance by one sample binomial tests. The reference value was estimated by calculating the LL of 99% CI for population proportion [ 49] using the largest previously employed sample sizes reaching 60 [ 32] and a generous assumption that the earlier sample proportion of ≤5-degree measurement differences was 0.99. Counts of the raters who passed the binomial tests were obtained for intuitive comparison. To assess the inter-goniometer ≤ 5-degree agreement, only the raters who passed the binomial test in both trials were included. Additionally, the best raters were selected by matching the individual successful raters across the three ≤ 5-degree agreement subgroups (i.e., across the inter-goniometer and the two intra-goniometer subgroups). Analysis of the study parts B Two photographs from the same patient depict contractures in the left small finger and the right middle finger.

Dijkstra PU, de Bont LG, van der Weele LT, Boering G: Joint mobility measurements: reliability of a standardized method. Cranio. 1994, 12: 52-57. Georgeu GA, Mayfield S, Logan AM: Lateral digital photography with computer-aided goniometry versus standard goniometry for recording finger joint angles. J Hand Surg Br. 2002, 27: 184-186. 10.1054/jhsb.2001.0692. For concurrent assessment of reliability, the pertinent mean squares were found by running two-factorial univariate ANOVAs [ 43]. Subject and rater were random effects because the participants were selected randomly and there was no interest in particular raters. Homogeneity of variances was tested with Leven’s test. The necessary variance components were calculated using the obtained mean squares. The intra-rater and inter-rater ICCs, their lower limits of 95% one-sided lower-limit confidence intervals (LLs of 95% one-sided L-L CI), and SEMs were simultaneously calculated across all raters for each goniometer-position-joint data set. Following the methodology for concurrent assessment of reliability [ 43] and previous suggestions regarding meaningful ICC values [ 38], the null hypothesis was that the ICCs were less than or equal to 0.75, and the alternative hypothesis was that the ICCs would be more than 0.75. The null hypothesis was considered rejected, if the LLs of 95% one-sided L-L CI for the ICCs were less than or equal to 0.75. Computation algorithms for concurrent assessment of reliability are presented in the Additional file 5.There is some question as to whether or not a goniometer is a sufficiently valid and reliable instrument to determine whether an intervention has been effective. [2] Bruton A, Ellis B, Goddard J: Comparison of visual estimation and goniometry for assessment of metacarpophalangeal joint angle. Physiotherapy. 1999, 85: 2011-2018. So overall greater reliability is obtained when measures are taken by the same therapist, using a standardised method with the same measurement tool assessed at the same time of day. [1] [9] [10] [11] [12] [13] [14] Goniometry Technique [ edit | edit source ] Mourcou Q, Fleury A, Diot B, Franco C, Vuillerme N. Mobile Phone-Based Joint Angle Measurement for Functional Assessment and Rehabilitation of Proprioception.Biomed Res Int. 2015; doi: 10.1155/2015/328142

Burr N, Pratt AL, Stott D: Inter-rater and intra-rater reliability when measuring interphalangeal joints: comparison between three hand-held goniometers. Physiotherapy. 2003, 89: 641-652. 10.1016/S0031-9406(05)60097-1. Kato M, Echigo A, Ohta H, Ishiai S, Aoki M, Tsubota S, Uchiyama E: The accuracy of goniometric measurements of proximal interphalangeal joints in fresh cadavers: comparison between methods of measurement, types of goniometers, and fingers. J Hand Ther. 2007, 20: 12-18. 10.1197/j.jht.2006.11.015. Lefevre-Colau MM, Poiraudeau S, Fermanian J, Mayoux-Benhamou MA, Bargy F, Revel M: Reliability of two goniometers in assessing rheumatoid finger mobility: Relationship between mobility and disability. Eura Medicophys. 2001, 37: 3-10. Groth GN, VanDeven KM, Phillips EC, Ehretsman RL: Goniometry of the proximal and distal interphalangeal joints, Part II: placement preferences, interrater reliability, and concurrent validity. J Hand Ther. 2001, 14: 23-29. 10.1016/S0894-1130(01)80021-1.

Wireless / Wired

Power analysis prior to the study was performed for a 2-sample t test for noninferiority, which calculated a sample size of 13 subjects based on a mean difference of 5°, a standard deviation of 10% of the expected measurement, α of 0.05, and a power of 0.80. Five degrees of difference is the accepted standard error in manual goniometry of the hand. 8, 9 For this study, the authors elected to include a larger sample size (n = 50). Shrout PE, Fleiss JL: Intraclass correlations: uses in assessing rater reliability. Psychol Bull. 1979, 86: 420-428. Two weeks before the study, the participants were sent step-by-step instructions with the appropriate images of the procedure and the equipment. At least a week before the study, the equipment and procedures were demonstrated to the participants live. Example try-angles, triangle rulers, and paper strips were distributed for individual training at home. Taking into account the unusual manipulative task of the diagrammatic goniometry, the participants learned to copy printed angles by using the paper goniometer individually or as participants of another study. Two days before the study, the participants were required to answer a short quiz testing the knowledge of their tasks in the study. Procedures on the day of study The results of all the analytical approaches support the suggestion that both goniometers can be used interchangeably. Significance of goniometer effect apparent from some of the 2x10 ANOVAs should be interpreted in conjunction with significant goniometer by rater interaction, indicating that the performance of the instrument tended to be depended on which the rater was using it. The small magnitudes of the differences between the reliability estimates of the techniques were not convincing enough to state disparity of the methods. In the three cases of failure to reject the null hypothesis for paper goniometer alone, the LLs of 95% one-sided L-L CIs levels above 0.7 can still be considered as an acceptable level of reliability for non-professional novice raters. Interchangeability of goniometers was also demonstrated by the binomial tests, which involved assessment of the inter-goniometer ≤ 5-degree agreement. It is notable, that the results of the proportion analysis echo the outcomes of parametric assessments indicating that the measurement consistency was rater and joint dependent. Parity of the goniometers was further shown by the results of the study parts B, indicating that data collected with both instruments can be similarly interpreted in an exploration of simulated change in joint range of motion over time. Decrease in the reliability estimates in the second stage of the study part A may be due to the weariness of the participants. Jones A, Sealey R, Crowe M, Gordon S. Concurrent validity and reliability of the simple goniometer iPhone app compared with the universal goniometer. Physiotherapy Theory and Practice. 2014; 30 (7): 512–516.

The study was approved by Vilnius regional ethics committee for biomedical research. Written informed consents of the participants were obtained before the study. Participants and study designThe long arm goniometers are more accurate for joints with long levers like the knee and hip joints.