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    This study developed a smart sock system using optical fiber technology to measure the toe grip function of individual toes. The system comprised Fiber Bragg grating (FBG) sensors incorporated into a sock garment for measuring maximum toe flexion displacements. Calibration equation of each FBG sensor was determined from 3D motion capture system on 10 female subjects. The validity of the smart sock system was checked by comparing maximum toe flexion displacement against the gold standard of 3D motion capture. The root mean squared error was 0.95 (0.57) cm across 10 toes. The magnitude of toe displacement and error was similar between the left and right feet. In conclusion, the FBG-based smart sock system can successfully measure maximum toe flexion displacements of individual toes simultaneously. This system can be developed to support the evaluation of toe grip function in clinical and field settings.


    • 1. Garth WP Jr, Miller ST, Evaluation of claw toe deformity, weakness of the foot intrinsics, and posteromedial shin pain, Am J Sport Med 17(6) :821–827, 1989. Crossref, ISIGoogle Scholar
    • 2. Mickle KJ, Munro BJ, Lord SR, Menz HB, Steele JR, Toe weakness and deformity increase the risk of falls in older people, Clinc Biomech 24(10) :787–791, 2009. Crossref, ISIGoogle Scholar
    • 3. Uritani D, Fukumoto T, Matsumoto D, Shima M, Reference values for toe grip strength among Japanese adults aged 20 to 79 years: a cross-sectional study, J Foot Ankle Res 7 :28, 2014. Crossref, ISIGoogle Scholar
    • 4. Menz HB, Morris ME, Lord SR, Foot and ankle characteristics associated with impaired balance and functional ability in older people, J Gerontol A Biol Sci Med Sci 60(12) :1546–1552, 2005. Crossref, ISIGoogle Scholar
    • 5. Goldmann JP, Sanno M, Willwacher S, Heinrich K, Brüggemann GP, The potential of toe flexor muscles to enhance performance, J Sport Sci 31(4) :424–433, 2013. Crossref, ISIGoogle Scholar
    • 6. de Win MM, Theuvenet WJ, Roche PW, de Bie RA, van Mameren H, The paper grip test for screening on intrinsic muscle paralysis in the foot of leprosy patients, Int J Lepr Other Mycobact Dis 70(1) :16–24, 2002. Google Scholar
    • 7. Tudor A, Ruzic L, Sestan B, Sirola L, Prpic T, Flat-footedness is not a disadvantage for athletic performance in children aged 11 to 15 years, Pediatrics, 123(3) :386–392, 2009. Crossref, ISIGoogle Scholar
    • 8. Morita N, Yamauchi J, Kurihara T, Fukuoka R, Otsuka M, Okuda T, Ishizawa N, Nakajima T, Nakamichi R, Matsuno S, Kamiie S, Shide N, Kambayashi I, Shinkaiya H, Toe flexor strength and foot arch height in children, Med Science Sport Exerc 47(2) :350–356, 2015. Crossref, ISIGoogle Scholar
    • 9. Hill KO, Meltz G, Fiber Bragg grating technology fundamentals and overview, J Lightwave Technol 15(8) :1263–1276, 1997. Crossref, ISIGoogle Scholar
    • 10. Kong PW, Chan CC, Heng ML, Liu Y, Leow Y, Fong, DT, Fiber Bragg grating sensors for clinical measurement of the first metatarsophalangeal joint quasi-stiffness, IEEE Sensors J 20(3) :1322–1328, 2020. Crossref, ISIGoogle Scholar
    • 11. Nix S, Smith M, Vicenzino B, Prevalence of hallux valgus in the general population: A systematic review and meta-analysis, J Foot Ankle Res 3 :21, 2010. Crossref, ISIGoogle Scholar
    • 12. Misu S, Doi T, Asai T, Sawa R, Tsutsumimoto K, Nakakubo S, Yamada M, Rei Ono R, Association between toe flexor strength and spatiotemporal gait parameters in community-dwelling older people, J Neuroeng Rehabil 11 :143, 2014. Crossref, ISIGoogle Scholar
    • 13. LeMoyne R, Transtibial powered prostheses: Single and dual actuator configurations, in Advances for Prosthetic Technology, Springer, Japan, 2016, pp. 93–110. CrossrefGoogle Scholar
    • 14. Chiacchiero M, Dresely B, Silva U, DeLosReyes R, Vorik B, The relationship between range of movement, flexibility, and balance in the elderly, Top Geriat Rehabilit 26(2) :148–55, 2010. Crossref, ISIGoogle Scholar
    Published: 7 May 2020