Subject-specific musculoskeletal model of the lower limb in a lying and standing position.
Accurate estimation of joint loads implies using subject-specific musculoskeletal models. Moreover, as the lines of action of the muscles are dictated by the soft tissues, which are in turn influenced by gravitational forces, we developed a method to build subject-specific models of the lower limb in a functional standing position. Bones and skin envelope were obtained in a standing position, whereas muscles and a set of bony landmarks were obtained from conventional magnetic resonance images in a lying position. These muscles were merged with the subject-specific skeletal model using a nonlinear transformation, taking into account soft tissue movements and gravitational effects. Seven asymptomatic lower limbs were modelled using this method, and results showed realistic deformations. Comparing the subject-specific skeletal model to a scaled reference model rendered differences in terms of muscle length up to 4% and in terms of moment arm for adductor muscles up to 30%. These preliminary findings enlightened the importance of subject-specific modelling in a functional position.
a LBM, Arts et Metiers ParisTech , Paris , France.
J
J
Hausselle
A
A
Assi
A
A
El Helou
E
E
Jolivet
H
H
Pillet
E
E
Dion
D
D
Bonneau
W
W
Skalli
D000328:Adult; D001696:Biomechanical Phenomena; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D035002:Lower Extremity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008297:Male; D008953:Models, Anatomic; D009068:Movement; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000502:physiology; D011187:Posture; D011859:Radiography