View Full Version : 3D marker placement (request for help)

10-08-1992, 02:22 AM
Dear Subscribers,

We have recently purchased a 3D motion analysis system and many problems
arised due to the placement and replacement of the reflective markers.
The program used to evaluate the range of motion of the major joints of the
lower limbs necessitates (amoung other things) some markers mounted on sticks
to be placed on the sacrum, on the lateral side of the thigh and on the
lateral side of the calf. The thigh marker is crucial to measure hip
rotations and pelvis moments. I my experience an inaccurate placement of
this marker may change the sign of hip rotation from internal to external.
Due to the lack of clear anatomical landmarks (specially on fatty subjects)
the reproducibility of my results is very poor.
Our equipement has been bought for presurgical evaluation of cerebral
palsied children.
If there is anyone who has overcome this difficulty, I would be grateful to
hear about your solutions; any advice on this topic would be most welcomed.

Yves Blanc
Laboratoire de Cinesiologie
Hopital Cantonal

Tel: 22 37 27 827
FAX: 22 347 64 86

E-Mail BLANC@cmu.unige.ch