View Full Version : Re: replies to : how to define upper limb technical array?

Nancy Black
07-18-1997, 07:02 AM
Please note that I misinterpreted the work of Liduin Meershoek in my
recent summary note...
Liduin's work did mount markers on a rigid base, similar to that
described by J. Williams (markers on raised pins), only using velcro and
elastic bandage to secure that base.
He goes on to point out that flexible arrays would be susceptible to
variations in skin movement, leading to analysis difficulties compared
with a rigid array.
See below...
Nancy Black __|~_)_I__)_|~_
Ecole de genie )_ __)_|_)__ __)
Universite de Moncton | )____) | EMAIL: blackn@umoncton.ca
Moncton, New Brunswick \\___|____|____|____// FAX: (506) 858-4082
E1A 3E9 CANADA \\ // PHONE: (506) 858-4079
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I doubt whether flexible arrays are better. You will end up with a lot of
deformation since skin displacement is different everywere. This will
especially hold for pronation and supination movements. It will be difficult
to interpretate the deformations and calculate joint angles. But maybe you
only hide these effects with rigid arrays. You will not see any deformation
but you will never know whether there is any movement between the bone and
the array. Personally I think that the displacement of a properly attached
array will be less compared with skin markers.

Liduin Meershoek
Vakgroep Functionele Morfologie
Faculteit Diergeneeskunde
Universiteit Utrecht
Yalelaan 1
3584 CL Utrecht
the Netherlands
tel. 030-2534324