Validity and reliability of arthrometer-based measures of the first ray relative and absolute mobility : a cadaveric biomechanical study

Article Article scientifique Article Validity and reliability of arthrometer-based measures of the first ray relative and absolute mobility : a cadaveric biomechanical study eng 2026-04-27 2026-06 author Moissenet Florent 0000-0001-6479-1911 864653 Département de chirurgie (CHIRU) author Chollet Mickaël 444892 author Praz Quentin 433568 Département de chirurgie (CHIRU) author Schoinas Spyridon 433569 Département de chirurgie (CHIRU) author Olivier Jeremy author Acker Antoine author Bailez Alberto author Assal Mathieu 41127 Département de chirurgie (CHIRU) author Armand Stéphane 0000-0001-9144-4982 636265 Département de chirurgie (CHIRU) 113340 10.1016/j.jbiomech.2026.113340 42061124 0021-9290 https://www.sciencedirect.com/science/article/pii/S0021929026001958 <p>First ray hypermobility is implicated in many forefoot pathologies, yet its quantitative assessment remains challenging. Instrumented methods have traditionally focused on isolated dorsal displacement of the first metatarsal, which may not reflect physiological load sharing within the forefoot. This cadaveric biomechanical study evaluated the reliability and construct validity of two arthrometer-based measures: the first ray absolute (FRAM) and relative (FRRM) mobility, respectively assessed under isolated loading of the first metatarsal and symmetrical loading of the first metatarsal and lesser metatarsals. Ten fresh-frozen cadaveric lower limb segments were tested using an automated forefoot arthrometer. Within-session reliability was quantified using intraclass correlation coefficients, standard error of measurement, and minimal detectable change. Construct validity was assessed by correlating FRAM and FRRM with a biomechanical reference construct defined as the sum of superior-inferior translations at the first tarsometatarsal and medial naviculo-cuneiform joints measured using optical motion capture. Linear mixed-effects models were used to characterise joint-level kinematic behaviour under each loading mode. FRRM demonstrated excellent within-session reliability (ICC=1.00) and a strong correlation with the reference construct (R=0.84, p=0.003). FRAM also showed excellent reliability (ICC=0.97) but higher absolute measurement error and a weaker, non-significant association with the reference construct (R=0.62, p=0.057). Symmetric loading engaged proximal first ray joints more effectively than isolated loading, which predominantly mobilised the first tarsometatarsal joint. These findings indicate that arthrometer-based assessment of the first ray mobility is sensitive to the loading mode and that symmetric loading provides a more biomechanically representative evaluation of the first ray mobility than traditional isolated approaches.</p> COSMIN guidelines First ray hypermobility Foot arthrometer Foot kinematics Forefoot disorders Dewey 617 57 Département de chirurgie 222 false 1464 Biomécanique et recherche translationnelle en chirurgie 1074 900 Laboratoire de cinésiologie 943 https://github.com/fmoissenet/LAXIPED_Toolbox Journal of biomechanics 203 a6a9cd99-763d-4af3-be07-bda51518a315 Article (Published version) Public 1-s2.0-S0021929026001958-main.pdf 2161854 application/pdf CC BY-4.0 5ff34a7d102a800ccb0ad6b6134ce8e25558943adad48bafbba26cb4f4651bf6 0080b518-2d1a-40d9-9728-d9d791e43be6 Supplemental data Public 1-s2.0-S0021929026001958-mmc1.docx 19818 application/vnd.openxmlformats-officedocument.wordprocessingml.document 4069313b2df9cc6e0410b9ec519ba357f5782ac6c28a57424640186b6a4ca0a8 openAccess Faculté de médecine / Section de médecine clinique / Département de chirurgie

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Validity and reliability of arthrometer-based measures of the first ray relative and absolute mobility : a cadaveric biomechanical study	Journal of biomechanics			2026	8	3

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Chollet, Mickaël