Test-retest reliability of an Android application (Protractor) for range of motion evaluation


  • Sabah Mohamed Elkady Department of Basic Science, Faculty of Physical Therapy, Cairo University, Egypt
  • Reda Kotb Abd Elrazik Department of Physical Therapy for Musculoskeletal Disorders and its Surgery, Faculty of Physical Therapy, Benha University, Egypt
  • Hossam Mohammed Alsaid Department of Physical Therapy for Neurology, Faculty of Physical Therapy, Cairo University, Egypt
  • Mohammed Youssef Elhamrawy Department of Physical Therapy, Faculty of Allied Medical Sciences, Middle East University, Amman, Jordan
  • Ahmed Mashaal Department of Physical Therapy, Faculty of Allied Medical Sciences, Isra University, Amman, Jordan.
  • Amany Refaat Mohamed Abdel Wahid Department of Physical Therapy for Surgery, Faculty of Physical Therapy, Cairo University, Egypt
  • Doaa Atef Department of Physical Therapy for Surgery, Faculty of Physical Therapy, Cairo University, Egypt
DOI: https://doi.org/10.6018/sportk.589561
Palabras clave: Range of Motion, Reliability, Smartphone, Mobile Application, Protractor


Several tools are used by physical therapists to assess the range of motion (ROM) for joints of the upper and lower limbs. However, most of them are costly, time-consuming, and difficult to use. The current study aimed to determine the within-visit test-retest reliability of an android application (App) (Protractor) for elbow, wrist and ankle joints range of motion evaluation in outpatients with post fracture fixation.  We evaluated the Android App (Protractor) in twenty-six patients with a mean age of 30 years, who had undergone operative treatment for fractures around the elbow, wrist, and ankle. These patients were recruited from the physiotherapy outpatient clinic at the Faculty of Medicine, Tanta University. Repeated measures were performed within the same session, focusing on motions in the sagittal plane for the elbow, wrist, and ankle joints. All measurements were conducted by the same investigator. Pearson correlation coefficient (r) and intra-class correlation coefficient (ICC) were calculated. Within-visit test retest intra-rater reliability for elbow, ankle, and wrist joints, ROM was excellent (r and ICC≥0.99) except for wrist joint flexion ROM, it was weak and insignificant. The mean group difference of measures obtained in the first and second measurements was close to zero, with the exception of wrist joint flexion, which was -5 degrees, and ankle joint plantar flexion, which was +2 degrees. The Smartphone android App (Protractor) displayed reasonable within-visit reliability.


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Alawna, M. A., Unver, B. H., & Yuksel, E. O. (2019). The Reliability of a Smartphone Goniometer Application Compared with a Traditional Goniometer for Measuring Ankle Joint Range of Motion. Journal of the American Podiatric Medical Association, 109(1), 22–29. https://doi.org/10.7547/16-128

Barker, K., Bowman, B., Galloway, H., Oliashirazi, N., Oliashirazi, A., & Mehta, S. (2016). Reliability, Concurrent Validity, and Minimal Detectable Change for iPhone Goniometer App in Assessing Knee Range of Motion. The Journal of Knee Surgery, 30(6), 577–584. https://doi.org/10.1055/s-0036-1593877

Behnoush, B., Tavakoli, N., Bazmi, E., Nateghi Fard, F., Pourgharib Shahi, M. H., Okazi, A., & Mokhtari, T. (2016). Smartphone and Universal Goniometer for Measurement of Elbow Joint Motions: A Comparative Study. Asian Journal of Sports Medicine, 7(2), e30668. https://doi.org/10.5812/asjsm.30668

Cicchetti, D., Bronen, R., Spencer, S., Haut, S., Berg, A., Oliver, P., & Tyrer, P. (2006). Rating Scales, Scales of Measurement, Issues of Reliability. Journal of Nervous & Mental Disease, 194(8), 557–564. https://doi.org/10.1097/01.nmd.0000230392.83607.c5

Divall, P., Camosso-Stefinovic, J., & Baker, R. (2013). The use of personal digital assistants in clinical decision making by health care professionals: A systematic review. Health Informatics Journal, 19(1), 16–28. https://doi.org/10.1177/1460458212446761

Elgueta-Cancino, E., Rice, K., Abichandani, D., & Falla, D. (2022). Measurement properties of smartphone applications for the measurement of neck range of motion: a systematic review and meta analyses. BMC Musculoskeletal Disorders, 23(1), 138. https://doi.org/10.1186/s12891-022-05066-6

Ferriero, G., Sartorio, F., Foti, C., Primavera, D., Brigatti, E., & Vercelli, S. (2011). Reliability of a New Application for Smartphones (DrGoniometer) for Elbow Angle Measurement. PM&R, 3(12), 1153–1154. https://doi.org/10.1016/j.pmrj.2011.05.014

Hahn, S., Kröger, I., Willwacher, S., & Augat, P. (2021). Reliability and validity varies among smartphone apps for range of motion measurements of the lower extremity: a systematic review. Biomedical Engineering / Biomedizinische Technik, 66(6), 537–555. https://doi.org/10.1515/bmt-2021-0015

Ishii, K., Oka, H., Honda, Y., Oguro, D., Konno, Y., Kumeta, K., Nishihara, S., Matsuyama, H., Kaneko, I., Takeuchi, Y., Watanabe, Y., Kawano, H., & Ogata, N. (2021). Accuracy and reliability of a smartphone application for measuring the knee joint angle. Journal of Physical Therapy Science, 33(5), 417–422. https://doi.org/10.1589/jpts.33.417

Jeon, I. C., Kwon, O. Y., Weon, J. H., Ha, S. M., & Kim, S. H. (2013). Reliability and Validity of Measurement Using Smartphone-Based Goniometer of Tibial External Rotation Angle in Standing Knee Flexion. Physical Therapy Korea, 20(2), 60–68. https://doi.org/10.12674/ptk.2013.20.2.060

Keogh, J. W. L., Cox, A., Anderson, S., Liew, B., Olsen, A., Schram, B., & Furness, J. (2019). Reliability and validity of clinically accessible smartphone applications to measure joint range of motion: A systematic review. PLOS ONE, 14(5), e0215806. https://doi.org/10.1371/journal.pone.0215806.

Knapp, P. W., Keller, R. A., Mabee, K. A., Shi, J., Pillai, R., & Frisch, N. B. (2022). Comparison of a Smartphone App to Manual Knee Range of Motion Measurements. Arthroplasty Today, 15, 43–46. https://doi.org/10.1016/j.artd.2021.09.005

Mitchell, K., Gutierrez, S. B., Sutton, S., Morton, S., & Morgenthaler, A. (2014). Reliability and validity of goniometric iPhone applications for the assessment of active shoulder external rotation. Physiotherapy Theory and Practice, 30(7), 521–525. https://doi.org/10.3109/09593985.2014.900593

Mohammad, W. S., Elattar, F. F., Elsais, W. M., & AlDajah, S. O. (2021). Validity and Reliability of a Smartphone and Digital Inclinometer in Measuring the Lower Extremity Joints Range of Motion. Montenegrin Journal of Sports Science and Medicine, 10(2), 47–52. https://doi.org/10.26773/mjssm.210907

Norkin, C. C., & White, D. J. (2009). Measurement of Joint Motion: A Guide to Goniometry. F.A. Davis.

Ockendon, M., & Gilbert, R. (2012). Validation of a Novel Smartphone Accelerometer-Based Knee Goniometer. Journal of Knee Surgery, 25(04), 341–346. https://doi.org/10.1055/s-0031-1299669

Portney, L. G., & Watkins, M. P. (2013). Foundations of Clinical Research - Applications to Practice. Pearson.

Sakata, M. S. B., Wassmuth, T., Ferreira, L. A. B., & Rossi, L. P. (2020). Analysis of the reliability of smartphone-based goniometric applications. Manual Therapy, Posturology & Rehabilitation Journal, 18, 1–6. https://doi.org/10.17784/mtprehabjournal.2020.18.0793

Shin, S. H., Ro, D. H., Lee, O. S., Oh, J. H., & Kim, S. H. (2012). Within-day reliability of shoulder range of motion measurement with a smartphone. Manual Therapy, 17(4), 298–304. https://doi.org/10.1016/j.math.2012.02.010

Takeda Y., & Furukawa, K. (2022). Clinical reliability and usability of smartphone goniometers for hip range of motion measurement. Journal of Physical Therapy Science, 34(6), 433–439. https://doi.org/10.1589/jpts.34.433

Vohralik, S. L., Bowen, A. R., Burns, J., Hiller, C. E., & Nightingale, E. J. (2015). Reliability and Validity of a Smartphone App to Measure Joint Range. American Journal of Physical Medicine & Rehabilitation, 94(4), 325–330. https://doi.org/10.1097/phm.0000000000000221

Wellmon, R. H., Gulick, D. T., Paterson, M. L., & Gulick, C. N. (2016). Validity and Reliability of 2 Goniometric Mobile Apps: Device, Application, and Examiner Factors. Journal of Sport Rehabilitation, 25(4), 371–379. https://doi.org/10.1123/jsr.2015-0041

Zienab A. Hussein, Ph.D.& M. Refaat, Ph.D., S. (2020). Uses of Smart Phones Application on Physical Therapy for Pediatric Evaluation: Systematic Review. The Medical Journal of Cairo University, 88(12), 1725–1731. https://doi.org/10.21608/mjcu.2020.116549

Cómo citar
Mohamed Elkady, S. ., Abd Elrazik, R. K., Mohammed Alsaid, H., Youssef Elhamrawy, M., Mashaal, A., Mohamed Abdel Wahid, A. R., & Atef, D. (2023). Test-retest reliability of an Android application (Protractor) for range of motion evaluation. SPORT TK-Revista EuroAmericana de Ciencias del Deporte, 12, 40. https://doi.org/10.6018/sportk.589561