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Van Den Bogert, Ton
03-15-2006, 04:03 AM
Dear Biomch-L subscribers,

We are in need of a method to estimate inertial properties for arm segments (upperarm, forearm, hand) in children and adolescents (age 10-15). For the lower extremity in young adults we have been using De Leva's equations (J Biomech 1996). De Leva's method, however, only considers total body mass and segment lengths and this makes it uncertain whether these equations can be extrapolated to other populations.

I do not know of any database with direct measurements (cadaveric, or gamma ray based) in children. The next best thing is probably to use an existing estimation method which uses additional information to represent body shape The Kwon3D website describes two methods which use circumference of body segments: Yeadon (1990) and Hanavan (1964). See http://kwon3d.com/theory/bspeq/mthd.html.

Jensen studied inertial properties in children using elliptical zone models (Med Sci Sports Exerc 1988). This work only provided inertial properties as a function of age, not subject specific measurements such as circumference Using the elliptical zone model for subject-specific estimates would be impractical for us.

A modified Hanavan model is extensively documented on Kwon3D.com and looks like it might be practical. This would require total body mass, plus 12 measurements on the upper extremity.

My specific questions are:

(1) If you do subject-specific upper extremity dynamics, which method do you use to estimate body segment parameters for your human subjects?

(2) It seems that the segment masses in the Hanavan method were fit to cadaveric data. Was there any cadaveric validation of the moments of inertia and centers of mass?

(3) Has anybody ever applied multiple estimation methods (De Leva, Hanavan, Yeadon, Jensen) to the same subjects and compared the results?

If you have information that may be of general interest, please post your response to Biomch-L. Any private replies will be summarized in a posting.

--

Ton van den Bogert

--

A.J. (Ton) van den Bogert, PhD
Department of Biomedical Engineering
Cleveland Clinic Foundation (ND-20)
9500 Euclid Avenue, Cleveland, OH 44195
Phone: (216) 444-5566 Fax: (501) 665-1506
http://www.lerner.ccf.org/bme/bogert/

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