View Full Version : stiffnesses and viscosities of the human hand

Laboratory Cybernetics
12-20-1993, 12:25 AM
Dear Biomch-L readers,
I deal now with the biomechanical modelling of human arm reaching
movement. The mechanical model of the human arm includes three links (the upper
arm, the forearm, the hand) and has seven degrees of freedom (three in the
shoulder joint, two in the elbow joint and two in the wrist joint). I assume
that the linear spring model can be used to describe the joint torques:
Ti = -S * (Xi - Xeqi) - V * Yi,
where i=1,2, ... 7 is degree of freedom number, T is the muscle torque,
X is the joint angle, Xeq is its equilibrium (final) value, Y is the angular
velocity, S is stiffness matrix, V is viscosity matrix. I need in my modelling
the numerical values for the elements of matrices S and V.
Some experimental data have been published concerning stiffnesses and
viscosities corresponding to the rotations around frontal axes of shoulder,
elbow and wrist joints. However I have not found any data about stiffnesses
and viscosities, corresponding to the rotations around sagittal and longitudinal
axes of the shoulder joint, to the rotation around longitudinal axe of the
elbow joint and to the rotation around the sagittal axe of the wrist joint.
Besides, matrices S and V are nondiagonal due to the existence of multijoint
muscles in the human hand. The values of nondiagonal elements of matrices S
and V seem to be the most hard to obtain.
Does anyone have any information on the matter? I would appreciate any
help from the Biomch-L community.
With best regards,
Elena Biryukova
Lab. of mathematical neurophysiology,
Institute of Higher Nervous Activity
and Neurophysiology of Russian Academy
of Sciences,
5a, Butlerov str., 117865, Moscow, Russia
E-mail: lmno@ihnerv.msk.su