Dear biomch-l members,

I am looking for a method to simulate the effect of the skin
artifact on the marker position.

The references that I have found (e.g., Che`ze et al.,
1995; Lu and O’Connor, 1999; Roux et al., 2002) used A sin
(w*t+Q) formulation to simulate skin movement artifacts,
where A is the amplitude of the noise, w is the frequency, t
is the simulated time, and Q is the phase angle. For a
given trial, the values of A, w and Q for each marker were
taken randomly to lie between zero and a set upper limit.

My question is whether this the standard way, or are there
different methods to simulated this effect?

Thank you very much for your help!

Chéze, L., Fregly, B.J., and Dimnet, J., 1995. A
solidification procedure to facilitate kinematic analyses
based on video system data. Journal of Biomechanics 28, pp.

Lu, T. W. and O’Connor, J.J., 1999. Bone position estimation
from skin marker coordinates using global optimisation with
joint constraints. Journal of Biomechanics 32, pp. 129–134

Roux, E., Bouilland, S., Godillon-Maquinghen, A.P., and
Bouttens, D., 2002. Evaluation of the global optimisation
method within the upper limb kinematics analysis. Journal of
Biomechanics 35, pp. 1279–1283.

Raziel Riemer
University of Illinois at Urbana-Champaign
Department of Mechanical & Industrial Eng.
Mail Address:
MC-244, 1206 W. Green Street
Urbana, Illinois 61801

Phone : (217)244-0763
FAX : (217)244-6534