Hagiga, A., M. Aly, M. Gumaa, A. R. Youssef, and T. Cubison, "Targeted muscle reinnervation in managing post-amputation related pain: A systematic review and meta-analysis", Pain Practice, vol. 23, issue 8, pp. 922-932, 2023.
Rehan Youssef, A., M. Gumaa, and M. Czub, "Virtual reality for pain management", Frontiers in Pain Research, vol. 4, issue 1, pp. 1274613, 2023. fpain-04-1274613_1.pdf

Biomechnaics I


assitive technology


Rehabilitation Engineering

Rehan Youssef, A., and M. Gumaa, "Virtual Reality in Orthopedic Rehabilitation", Virtual Reality in Health and Rehabilitation: CRC Press, 2020.
Abdo, N., B. ALSaadawy, E. Embaby, and A. R. Youssef, "Validity and reliability of smartphone use in assessing balance in patients with chronic ankle instability and healthy volunteers: A cross-sectional study.", Gait & posture, vol. 82, pp. 26-32, 2020. Abstract

BACKGROUND: Chronic ankle instability (CAI) is associated with defective posture control and balance; thus, a proper assessment of these impairments is necessary for effective clinical decision-making. There is a need for portable, valid, and reliable methods to facilitate the easy collection of real-world data, such as mobile phones.

RESEARCH QUESTION: Is the smartphone "MyAnkle" application valid and reliable in assessing balance in patients with CAI and healthy volunteers?

METHODS: This was a cross-sectional study. Sixty-five participants completed two assessment sessions, including 31 patients (n = 41 ankles with CAI and 21 asymptomatic ankles) and 34 healthy volunteers (n = 68 ankles). In each session, dynamic single-leg stance balance was measured simultaneously using the "MyAnkle" application and the Biodex balance system (BBS) version 3. Testing was conducted at three levels of BBS difficulty-4 (D4, hard, loose platform), 6 (D6, moderate), and 8 (D8, easy, stiffer platform)-and repeated with opened and closed eyes. Both limbs were tested in a random order by two independent blinded assessors.

RESULTS: The two devices showed significant poor-to-moderate correlations when eyes were closed (p < 0.05). For discriminant validity, the application did not distinguish the two study groups in all tested conditions (p > 0.05), whereas the BBS weakly to moderately distinguished the dominant limbs in the two groups at all difficulty levels with eyes-open and at D8 with eyes-closed regardless to limb dominance. For reliability, a significantly poor to moderate inter-session reliability was noted for the two devices.

SIGNIFICANCE: "MyAnkle" application is valid in assessing balance in patients with CAI when the eyes are closed. However, similarly to BBS, its one-week test-retest reliability may be insufficient for accurate follow-up of balance changes and need to be interpreted with caution. Future studies need to establish its inter-tester reliability and its usefulness in telerehabilitation.

Abdeldaiem, A. S., E. S. B. Saweeres, A. - E. A. - E. Shehab-Eldien, A. F. Mannion, and A. R. Youssef, "Cross-cultural adaptation and validation of the Arabic version of the Core Outcome Measures Index for the back (COMI-back) in patients with non-specific low back pain.", European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, vol. 29, issue 10, pp. 2413-2430, 2020. Abstract

PURPOSE: To cross-culturally adapt the Core Outcome Measures Index for the back (COMI-back) for the Arabic language and to test its reliability and validity in Egyptian patients with non-specific low back pain (LBP).

METHODS: COMI-back was translated and cross-culturally adapted into Arabic according to standard guidelines. Its construct validity was assessed in 85 patients with chronic LBP (mean (± SD) age, 41.1 (± 10.4) years and 65/85 (76.5%) female) who completed a booklet of questionnaires including the Arabic versions of COMI-back, Roland Morris disability questionnaire, Oswestry disability index, the short form health survey 36, and the visual analogue scale for back pain. Test-retest reliability was assessed in 52 participants who completed the booklet again within 7 days.

RESULTS: Floor effects (worst status; 1.2-10.6%) and ceiling effects (best status; 1.2-11.8%) for COMI-back were acceptable, except for symptom-specific well-being (18.8%, floor), leg pain (23.5%, ceiling), and work disability (31.8%, ceiling). The COMI item scores correlated with those of the reference questionnaires (ρ = 0.45-0.88) to the hypothesized extent, except for the COMI symptom-specific well-being (ρ = 0.16-0.17) and quality of life (ρ = 0.38). The intra-class correlation coefficient for the summary score was 0.90, whereas that of the individual items ranged from 0.71-0.92. The standard error of measurement and minimal detectable change for the summary score were 0.51 and 1.41 points, respectively. The predefined hypotheses for construct validity and reliability were largely confirmed.

CONCLUSION: The Arabic version of COMI-back represents a valid and reliable instrument for use in Arabic-speaking patients with non-specific LBP.