PDA

View Full Version : Passive moments at elbow joint

09-12-2004, 06:23 PM
Dear Sirs,

I am working on my PhD on the Control System Laboratory
of the Mechanical Engineering Department of the National
Technical Universoty of Athens, Greece.

I am working on a dynamic model of the
human forearm-arm, concerning the flexion-extension of
the elbow joint.

As I have seen on a paper I should include passive moment
for the elbow joint, which is calculated by the following
formula:

M(q) = Ko*q + bo*q_dot + k1*(exp(K2*q) -1)

where q = angle of joint
q_dot = velocity (=dq/dt)

I wonder if it is critical to be added, and where
can I fing those parameters: Ko, K1, K2, bo

This formula is presented in the following paper:

Winters, J. M. and Stark, L. (1985) Analysis of fundamental human movements patterns
through the use of in-depth antagonistic muscle models. IEEE Trans. biomed. Engng 32,
826-839.

I would be very gratefull if anyone can send me this paper
in pdf format, or advice me of this passive moment, and the
significance of its existance in a dynamic model.

The equation of the model that I have already developed is just
the following, without any friction parts:

(I+m*d^2)*q_ddot + m*g*d*cos(q) = M

where I : moment of inertia with respect to elbow joint
d : the distance between the joint and the center of mass
of the forearm+hand
q : the angle of joint
q_ddot : second derivative of angle q
m : mass of forearm+hand
g : gravity
M : torque produced by the muscle force

*****************************************
PhD Candidate
Control Systems Laboratory
Mechanical Eng. Dept
National Technical University of Athens
9 Heroon Polytechniou Str.,
Zografou Athens 15700, Greece
Phone : ++30 - 210 - 7723656
http://users.ntua.gr/partem/
*****************************************

-----------------------------------------------------------------
To unsubscribe send SIGNOFF BIOMCH-L to LISTSERV@nic.surfnet.nl
For information and archives: http://isb.ri.ccf.org/biomch-l