title: Muscle parameters estimation based on biplanar radiography.
abstract: The evaluation of muscle and joint forces in vivo is still a challenge. Musculo-Skeletal (musculo-skeletal) models are used to compute forces based on movement analysis. Most of them are built from a scaled-generic model based on cadaver measurements, which provides a low level of personalization, or from Magnetic Resonance Images, which provide a personalized model in lying position. This study proposed an original two steps method to access a subject-specific musculo-skeletal model in 30 min, which is based solely on biplanar X-Rays. First, the subject-specific 3D geometry of bones and skin envelopes were reconstructed from biplanar X-Rays radiography. Then, 2200 corresponding control points were identified between a reference model and the subject-specific X-Rays model. Finally, the shape of 21 lower limb muscles was estimated using a non-linear transformation between the control points in order to fit the muscle shape of the reference model to the X-Rays model. Twelfth musculo-skeletal models were reconstructed and compared to their reference. The muscle volume was not accurately estimated with a standard deviation (SD) ranging from 10 to 68%. However, this method provided an accurate estimation the muscle line of action with a SD of the length difference lower than 2% and a positioning error lower than 20 mm. The moment arm was also well estimated with SD lower than 15% for most muscle, which was significantly better than scaled-generic model for most muscle. This method open the way to a quick modeling method for gait analysis based on biplanar radiography.
authors.affiliation: a LBM/Institut de Biomecanique Humaine Georges Charpark , Arts et Metiers ParisTech , Paris , France .
authors.forename: G
authors.initials: G
authors.lastname: Dubois
authors.affiliation: a LBM/Institut de Biomecanique Humaine Georges Charpark , Arts et Metiers ParisTech , Paris , France .
authors.forename: P
authors.initials: P
authors.lastname: Rouch
authors.affiliation: a LBM/Institut de Biomecanique Humaine Georges Charpark , Arts et Metiers ParisTech , Paris , France .
authors.forename: D
authors.initials: D
authors.lastname: Bonneau
authors.affiliation: b Institut Langevin, Laboratoire Ondes et Acoustique, CNRS UMR 7587, ESPCI ParisTech, INSERM ERL U979 , Universite Paris VII , Paris , France .
authors.forename: J L
authors.initials: JL
authors.lastname: Gennisson
authors.affiliation: a LBM/Institut de Biomecanique Humaine Georges Charpark , Arts et Metiers ParisTech , Paris , France .
authors.forename: W
authors.initials: W
authors.lastname: Skalli
mesh_terms: D004307:Dose-Response Relationship, Radiation; D006801:Humans; D035002:Lower Extremity / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008954:Models, Biological; D009068:Movement; D018482:Muscle, Skeletal / Q000502:physiology*; D011187:Posture; D011859:Radiography / Q000379:methods*
keywords: Stereoradiography; gait analysis; lower limb; muscle