Relative masses of body parts

Dervorin · June 18, 2009, 10:15pm

My physics teacher would never have let me get away with saying “weights” when I really meant masses. Be that as it may, while working out at the gym today, I was wondering how the various bits of the body compare in mass - if we were to split up, let’s say, into legs, arms, torso and head, what would be the approximate proportions for the average human?

I’m assuming moderately fit, not obese or bulked up, and I assume it would vary between men and women, but is there some sort of average estimate I can work with here?

Sage_Rat · June 18, 2009, 10:28pm

An adult, human head weighs about 10 pounds.

Kent_Clark · June 18, 2009, 10:29pm

Not mass, but area, but maybe it will help. The Rule of Ninesis used in treating burn patients. It does a pretty good job of breaking the surface area into roughly equal parts.

CalMeacham · June 18, 2009, 11:29pm

When I was working on Biomechanics, I learned that the Federal Government had funded several studies on this topic, performing several ghoulish experiments were corpses were frozen and carefully sawed into plates, which were then weighed. As a result, there are reports listing body part masses, moments of inertia, and radii of gyration, along with regression formulas that allow them to calculate such properties of living people without having to cut them into similar frozen bits.

One report is by Wilfred Dempster, another by Clauser McConville, and Yung. You can also look at the Stapp Car Crash Conferences for similar results.

Title: Properties of body segments based on size and weight Supported in part by research grants from the Public Health Service National Institutes of Health (GM-07741-06), and from the office of Vocational Rehabilitation (RD-216 60-C), with support a dozen years earlier from a research contract with the Anthropometric Unit of the Wright Air Development Center, Wright-Patterson Air Force Base, Dayton, Ohio (AF 18 (600)-43 Project no. 7414).
Authors: Dempster, W. T. (Wilfrid Taylor)
Gaughran, George R. L.
Issue Date: Jan-1967
Publisher: Wiley Subscription Services, Inc., A Wiley Company
Citation: Dempster, Wilfrid Taylor; Gaughran, George R. L. (1967).“Properties of body segments based on size and weight Supported in part by research grants from the Public Health Service National Institutes of Health (GM-07741-06), and from the office of Vocational Rehabilitation (RD-216 60-C), with support a dozen years earlier from a research contract with the Anthropometric Unit of the Wright Air Development Center, Wright-Patterson Air Force Base, Dayton, Ohio (AF 18 (600)-43 Project no. 7414). .” American Journal of Anatomy 120(1): 33-54. <http://hdl.handle.net/2027.42/49638>
Abstract: Values are presented for body constants based on a study of nine male white cadavers of normal appearance and average build. The limb data are supplemented by a further analysis of 11 upper and 41 lower limbs. Techniques used in the study form standard procedures that can be duplicated by subsequent workers. Each cadaver was measured, weighed, and somatotyped. Joints were placed in the midposition of the movement range and the body was frozen rigid. Joint angles were bisected in a systematic dismemberment procedure to produce unit segments. These segment lengths were weighed, measured for linear link dimensions, and analysed for segment volumes. The segment centers of mass were located relative to link end points as well as in relation to anatomical landmarks. Finally, each segment was dissected into its component parts and these were weighed. The specific gravity of each body part was calculated separately. Data are expressed in mean values together with standard deviations and, where available, are correlated and evaluated with other values in the literature.
ISSN: 0002-9106
1553-0795
DOI: 10.1002/aja.1001200104
Appears in Collections: Interdisciplinary and Peer-Reviewed

http://deepblue.lib.umich.edu/handle/2027.42/49638

See also:

http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=AD0087892

http://www.dh.aist.go.jp/bodyDB/m/e-k-15.html

For Clauser et al:

Accession Number : ADA016485

Title : Investigation of Inertial Properties of the Human Body

Descriptive Note : Final rept. Apr 1972-Dec 1974

Corporate Author : AIR FORCE AEROSPACE MEDICAL RESEARCH LAB WRIGHT-PATTERSON AFB OH

Personal Author(s) : Chandler, R. F. ; Clauser, C. E. ; McConville, J. T. ; Reynolds, H. M. ; Young, J. W.

Handle / proxy Url : http://handle.dtic.mil/100.2/ADA016485 Check NTIS Availability…

Report Date : MAR 1975

Pagination or Media Count : 171

Abstract : Knowledge of the anthropometric parameters of the human body is essential for understanding of human kinetics and particularly for the design and testing of impact protective systems. Considerable information is available on the size, weight and center of mass of the body and its segments. This report supplements existing information with data regarding mass distribution characteristics of the human body as described by the principal moments of inertia and their orientation to body and segment anthropometry. The weight, center of mass location and principal moments of inertia of six cadavers were measured, the cadavers were then segmented and the mass, center of mass, moments of inertia and volume were measured on the fourteen segments from each cadaver. Standard and three-dimensional anthropometry of the body and segments was also determined.

Descriptors : *INERTIA, *BIOMECHANICS, *ANTHROPOMETRY, MATHEMATICAL MODELS, HUMANS, MASS, HUMAN FACTORS ENGINEERING, IMPACT SHOCK, PROTECTIVE EQUIPMENT

Subject Categories : STRESS PHYSIOLOGY

Distribution Statement : APPROVED FOR PUBLIC RELEASE

http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA016485
This page gives actual regression data, if yyou want to figure it out on yourself:

http://www.dh.aist.go.jp/bodyDB/m/table/e-k-01_v_table.html

That’s from memory, aided by Google Scholar, from 30 years ago. Pretty good, huh?