Fig 1.
Process for data acquisition and post processing.
Fig 2.
(A) Fresh sheep elbow specimen with ligaments and synovial capsule, equipped with tracking clusters. (B) Sheep elbow specimen after removal of all soft tissue by boiling. (C) Composition of tracking clusters: Location of the speckle tracking mark relative to the 3D scanner frame.
Fig 3.
(1) Extension force. (2) Flexion force. (3) Manual actuation.
Fig 4.
Rigid body displacement defined by the screw axis theory.
ωi: angular velocity vector, di: magnitude of the translation part of the displacement, ni: direction vector of the screw axis, Ai: orthogonal projection of Oi on the screw axis.
Fig 5.
Defined anatomical reference system.
(A) Geometric construction of the point Oβ, origin of the joint frame. (B) Geometric construction of the point CW, centre of the carpal joint. (C) Geometric construction of the elbow joint frame axis. Am: mean of Ai points, nm: mean flexion axis, CS: Centre of the a best-fitting sphere of the humeral head.
Fig 6.
OpenSim model of the right thoracic limb of a sheep with initial elbow modelling as revolute joint.
Fig 7.
Decomposed elbow displacements.
Mean and error bar of the 5 displacements as function of the flexion angle for fresh specimens with ligaments and dry bone specimens.
Fig 8.
Mean rotation axis location on distal humerus epiphysis sagittal view.
Fig 9.
Simulated reaction forces at the elbow.