1. Biomechanics and Bone
Stress in Anthr opolog y
Michelle Beckhorn; Session 1; 7 May 2012; Cave

2. Biomechanics
 Application of mechanical
principles to biological systems
 Used in anthropology to explain skeletal
variation among populations past and
present
 Can be used to understand cultural
practices such as throwing spears, heavy
workloads, spatial movement, knapping,
etc.

3. Methods of
Understanding
Biomechanics
 Wolff’s law states simply that mechanical
loading influences bone structure
 Bone function adaptation states that
mechanical deformation or strain of bone
tissue occurs under mechanical loading.
 Body Size
 Muscle Activity
 Example: robusticity of the long bone diaphysis
between modern populations and past
populations

4. Variations to Consider
 Diet
 Disease
 Age at death
 Genetics
 Hormones
 Gender
 Size

5. Aspects to consider in
variations
 Because of the high variations within
populations, it is most accurate to
compare sides within an individual
than one individual to another.
 The dominant side will exhibit bone
stress marks resulting from
mechanical load or movement.
 Within a population, if there are
many individuals with such marks,
the cultural trend can be better
assessed
 Cold environments can accelerate
bone stress due to blood vessel
constriction
 Age at which mechanical strain
begins affects the severity of the
bone stress.

6. Early Thule of the Hudson
Bay
 Supports evidence
of umiaks
 Kayaker’s Clavicle
and humor stress
strong to heavy
 Gender role
differences
 Late start
 Hunting changes
from whaling to
seal
 90 percent left
handedness

7. Evolutionary Trends in
Bone Robusticity
 Over the past two million years
bone robusticity has decreased
by 30%
 Resulting from the decrease in
walking long distances,
mechanical load and
introduction of agriculture and
industry.
 Increase of potential
osteoporosis
 Physical environment and
effects of cultural practices

8. Conclusion
 Taking into consideration
the variations listed, we
can understand how culture
can effect the amount of
mechanical loads which
influences bone stress such as
robusticity on the long bone.
 Archaeologists can use bone
stress marks to understand
evolutionary and cultural trends
of populations past and
present.

9. References
 Hawkey, Diane E., Charles F. Merbs. Activity-induced musculoskeletal
stress markers (MSM) and subsistence strategy changes among ancient
Hudson Bay Eskimos. International Journal of Osteoarchaeology.
Volume 5, Issue 4, pages 324–338, December 1995.
 M. ANNE KATZENBERG, Shelly Saunders. Biological Anthropology of
the Human Skeleton. John Wiley and Sons Inc. Hoboken, NJ. 2008