Objective. The development of a novel three-dimensional mathematical m
odel of passive human joint torques that is of practical use, takes in
to account the complex non-linear interactions that exist between the
moments generated by the various passive structures spanning the joint
in question, and is applicable to all types of articular joints. Desi
gn. Mathematical model validated by practical implementation, Backgrou
nd. Previous models of passive human joint torques were predominantly
one-dimensional and did not take into account the interactions of the
various structural components, Methods. Mathematical modelling is used
in conjunction with repeated passive torque experiments on the right
elbow joint of a healthy 29-year-old male, On the basis of the experim
entally observed torque-angle data, the full set of articular model pa
rameters characterizing the two-dimensional passive elastic torque fun
ction of the subject's right elbow joint could be determined. Results.
In addition to the passive elastic torque functions, the two-dimensio
nal contour of the elbow joint's articular boundaries was also obtaine
d. Conclusions. The present model is especially useful for assessing c
ertain pathological conditions in any body joint investigated, and in
addition is best suited for the inclusion in large-scale dynamic simul
ation models of the human neuromusculoskeletal system. Relevance Both
the contour of a joint's articular boundaries and the diagrams of its
passive elastic moment functions as computed by the present model can
be used as clinical indicators for possibly abnormal and impaired join
t mobility. (C) Elsevier Science Ltd.