title: Motion representation of the long fingers: a proposal for the definitions of new anatomical frames.
abstract: Despite the availability of the International Society of Biomechanics (ISB) recommendations for the orientation of anatomical frames, no consensus exists about motion representations related to finger kinematics. This paper proposes novel anatomical frames for motion representation of the phalangeal segments of the long fingers. A three-dimensional model of a human forefinger was acquired from a non-pathological fresh-frozen hand. Medical imaging was used to collect phalangeal discrete positions. Data processing was performed using a customized software interface ("lhpFusionBox") to create a specimen-specific model and to reconstruct the discrete motion path. Five examiners virtually palpated two sets of landmarks. These markers were then used to build anatomical frames following two methods: a reference method following ISB recommendations and a newly-developed method based on the mean helical axis (HA). Motion representations were obtained and compared between examiners. Virtual palpation precision was around 1mm, which is comparable to results from the literature. The comparison of the two methods showed that the helical axis method seemed more reproducible between examiners especially for secondary, or accessory, motions. Computed Root Mean Square distances comparing methods showed that the ISB method displayed a variability 10 times higher than the HA method. The HA method seems to be suitable for finger motion representation using discrete positions from medical imaging. Further investigations are required before being able to use the methodology with continuous tracking of markers set on the subject's hand.
authors.affiliation: Laboratory of Anatomy, Biomechanics and Organogenesis (LABO), Faculty of Medicine, Université Libre de Bruxelles (ULB), Belgium(1). Electronic address: jcoupier@ulb.ac.be.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Coupier
authors.affiliation: Laboratory of Anatomy, Biomechanics and Organogenesis (LABO), Faculty of Medicine, Université Libre de Bruxelles (ULB), Belgium(1).
authors.forename: Fédor
authors.initials: F
authors.lastname: Moiseev
authors.affiliation: Laboratory of Anatomy, Biomechanics and Organogenesis (LABO), Faculty of Medicine, Université Libre de Bruxelles (ULB), Belgium(1).
authors.forename: Véronique
authors.initials: V
authors.lastname: Feipel
authors.affiliation: Laboratory of Anatomy, Biomechanics and Organogenesis (LABO), Faculty of Medicine, Université Libre de Bruxelles (ULB), Belgium(1).
authors.forename: Marcel
authors.initials: M
authors.lastname: Rooze
authors.affiliation: Laboratory of Anatomy, Biomechanics and Organogenesis (LABO), Faculty of Medicine, Université Libre de Bruxelles (ULB), Belgium(1).
authors.forename: Serge
authors.initials: S
authors.lastname: Van Sint Jan
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D003627:Data Interpretation, Statistical; D005385:Fingers / Q000502:physiology*; D006225:Hand / Q000502:physiology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008953:Models, Anatomic; D009068:Movement; D015588:Observer Variation; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012984:Software; D014057:Tomography, X-Ray Computed
keywords: Anatomical frames; Finger joint; Helical axis; Motion representation; Virtual palpation