Christopher B. Ruff, PhD

Christopher B. Ruff, PhD

Christopher B. Ruff, PhD

Professor Emeritus

My research explores how variation in skeletal morphology is related to mechanical forces applied during life. Many experimental and comparative studies show that the skeleton adapts to its mechanical environment, both developmentally and through evolutionary time, by altering its structural organization. Thus, using engineering principles, the preserved morphology of skeletal elements can be used to reconstruct past behavior and other characteristics such as body size and proportions. My work has applied this general approach to a variety of issues in vertebrate biology, focusing in particular on the primate postcranial skeleton: locomotor adaptations among anthropoid primates, the evolution of human bipedal locomotion, reconstruction of stature and body mass, bioarchaeological studies of various recent populations, climatic adaptation, and skeletal growth and aging in both humans and nonhuman primates. My current research is focused on how changes in subsistence strategy and other environmental variables affected skeletal morphology in Holocene European populations; the interaction between locomotion, obstetrics, and body shape among early hominins; and the effects of locomotor transitions during growth on skeletal structure in gorillas and other hominoids.



  • Ph.D. Biological Anthropology, University of Pennsylvania, 1981
  • B.A. Anthropology, Stanford University, 1975

Research Focuses

  • biomechanics and primate locomotion
  • evolution of the hominoid postcranium
  • skeletal growth and development
  • osteoporosis
  • skeletal remodeling & behavioral reconstruction in human populations

Special Projects

Excel file with modern human data set used in Ruff et al., 2020, Am. J. Phys. Anthropol. DOI: 10.1002/ajpa.24090

European data set: Excel file and Notes (see Ruff, C.B. (ed.). (2018) Skeletal variation and adaptation in Europeans: Upper Paleolithic to the Twentieth Century. Hoboken: Wiley Blackwell)

Note on 7/26/22: The most recent posted versions of the data file and notes contained errors and omissions. If you downloaded the previous versions in 2021 or 2022, please discard those and substitute the current version.

Gorilla Body Proportions Data Set: Excel file
Notes on gorilla body proportions data set: Word Doc

Automated bone Cross-Section reconstruction workspace, instructions and supplementary materials for R (from supporting information in AJPA 142:665-669) – updated 5/13.

Web resource for the MomentMacro for calculating cross-sectional properties (updated 2/16; now includes calculation of polar section modulus, Zp)

Calculating Moments: MomentMacro

MomentMacro calculates section properties (areas, second moments of area, section moduli) for cross-sectional images. The most current version, MomentMacroJ v1.4B, works with ImageJ on both PC and Mac platforms. (Note that earlier versions that worked with NIH Image are no longer supported.) To install and run the program follow the links below. The option for drawing principal axes on section images is currently nonoperational.

DOWNLOAD (right-click and choose “save target” or “save as…”)



An object with known characters is also provided here (a TIF formatted image of a washer, scale = 12.2 pixels/mm), and can be used to validate individual use of MOMENTMACRO:

washer.tif (right-click and choose “save target” or “save as…”)

washer properties (Microsoft Excel file) (right-click and choose “save target” or “save as…”)

**Note: If MOMENTMACRO is saved as a “text file with line breaks,” the macro may not run. The line breaks insert carriage returns into the longer lines of code and must be deleted.

MOMENTMACRO is provided for free download by Dr. Christopher Ruff (contact by e-mail).

2002 Amer. J. Phys. Anthropol. 119: 305-342. Excel file of primate structural properties
(Please note that this file was updated on 15 April 2006, correcting errors in some F50Zp property values.)

Web resource: EXCEL Macro for computing cross-sectional geometric properties using the eccentric ellipse model “EEM_Macro”: Macro (Excel Macro) and Instructions (PDF) (from JHE 47:221-235)

Selected Publications

Ruff, C. B., Sylvester, A. D., Rahmawati, N. T., Suriyanto, R., Storm, P., Aubert, M., Joannes-Boyau, R., Berghuis, H., Pop, E., Batenburg, K. J., Coban, S. B., Kostenko, A., Noerwidi, S., Renema, W., Adhityatama, S., & Joordens, J. C. (2022) Two Late Pleistocene human femora from Trinil, Indonesia: Implications for body size and behavior in Southeast Asia. J. Hum. Evol.

Ruff, C.B., Junno, J.-A., Burgess, M.L., Canington, S.L., Harper, C., Mudakikwa, A., and McFarlin, S.M. (2022) Body proportions and environmental adaptation in gorillas. Am. J. Biol. Anthropol. 177: 501-529. DOI:

Ruff, C.B., Wunderlich,  R.E., Hatala, K.G., Tuttle, R.H., Hilton, C.E., D’Août , K., Webb, D.M., Hallgrímsson, B., Musiba, C., and Baksh, M. (2021) Body mass estimation from footprint size in hominins. J. Hum. Evol. 156: 102997. DOI:

Ruff, C.B., Junno, J.A., Eckhardt, W., Gilardi, K., Mudakikwa, A., and McFarlin, S.C. (2020) Skeletal ageing in Virunga mountain gorillas. Phil. Trans. R. Soc. B. 375: 20190606.  DOI:

Ruff, C.B., Squyres, N., and Junno, J.A. (2020) Body mass estimation in hominins from humeral articular dimensions. Am. J. Phys. Anthropol. 173: 480-499. DOI:

Ruff, C.B., Higgins, R.W., and Carlson, K.J. (2020) Long bone cross-sectional geometry. In: Zipfel, B., Richmond, B.G., and Ward, C.V. (eds), Hominin postcranial remains from Sterkfontein, South Africa, 1936-1996. Oxford: Oxford Univ. Press, pp. 307-320.

Ruff, C.B., Harper, C., Goldstein, D., Daegling, D., and McGraw, W.S. (2019) Long bone structural proportions and locomotor behavior in Cercopithecidae. J. Hum. Evol. 132: 47-60. DOI:

Ruff C. B. (2019) Biomechanical analyses of archaeological human skeletal samples. In: Katzenburg, M.A. and Grauer, A.L. (eds.), Biological anthropology of the human skeleton, 3rd ed. New York: John Wiley and Sons, Inc. , pp. 189-224.

Ruff, C.B., Burgess, M.L., Squyres, N., Junno, J.-A., Trinkaus, E. (2018) Lower limb articular scaling and body mass estimation in Pliocene and Pleistocene hominins. J. Hum. Evol., 115: 85-111. DOI:

Ruff, C.B., Burgess, M.L., Junno, J.-A., Mudakikwa, A., Zollikofer, P.E., Ponce de Leon, M.S., McFarlin, S.C. (2018) Phylogenetic and environmental effects on limb bone structure in gorillas. Am. J. Phys. Anthropol., 166: 353-372. DOI:

Ruff, C.B. (2018) Biomechanical analyses of archaeological human skeletons. In: Biological Anthropology of the Human Skeleton, 3rd ed. Katzenberg, M.A. and Grauer, A.L., eds. Hoboken: Wiley Blackwell, pp. 189-224.

Ruff, C. (2017) Mechanical constraints on the hominin pelvis and the “obstetrical dilemma”. Anat. Rec. 300:946-955. DOI: 10.1002/ar.23539

Ruff, C.B., Burgess, M.L., Ketcham, R.A., and Kappelman, J. (2016) Limb bone structural proportions and locomotor behavior in A.L. 288-1 (“Lucy”). PLOS ONE 11. DOI: e0166095

Ruff, C.B. and Burgess, M.L. (2015) How much more would KNM-WT 15000 have grown? J. Hum. Evol. 80: 74-82. (view from Elsevier JHE page)

Ruff, C.B., Puymerail, L., Machiarelli, R., Sipla, J., and Ciochon, R.L. (2015) Structure and composition of the Trinil femora: functional and taxonomic implications. J. Hum. Evol.80: 147-158. (view from Elsevier JHE page)

Ruff, C.B., Holt, B.M., Niskanen, M., Sladek, V., Berner, M., Garofalo, E., Garvin, H.M., Hora, M., Junno, J.-A., Schuplerova, E., Vilkama, R., and Whittey, E. (2015) Gradual decline in mobility with the adoption of food production in Europe. Proc. Natl. Acad. Sci. 112: 7147-7152. (view from PNAS page)

Ruff, C.B., Burgess, M.L., Bromage, T.G., Mudakikwa, A., McFarlin, S.C. (2013) Ontogenetic changes in limb bone structural proportions in mountain gorillas (Gorilla beringei beringei). J. Hum. Evol. 65: 693-703. (view from Elsevier JHE page)

Ruff, C.B., Garofalo, E., and Holmes, M.A. (2013) Interpreting skeletal growth in the past from a functional and physiological perspective. Am. J. Phys. Anthropol. 150:29-37. (view from Wiley AJPA page)

Ruff, C.B. and Higgins, R. (2013) Femoral neck structure and function in early hominins. Am. J. Phys. Anthropol. 150:512-525. (view from Wiley AJPA page)

Ruff C.B., Holt, B.M., Niskanen, M., Sladek, V., Berner, M., Garofalo, E., Garvin, H.M., Hora, M., Maijanen, H., Niinimaki, S., Salo, K., Schuplerova, E., and Tompkins, D. (2012) Stature and body mass estimation from skeletal remains in the European Holocene. Am. J. Phys. Anthropol. 148: 601-617. (view from Wiley AJPA page)


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