Read Rebecca's anthropologically awesome adventures!See reading materials and other websites that makes Rebecca tick!Search through Rebecca's anthropologically awesome adventures!Meet Rebecca and follow her lead!

Class Notes: Bioarchaeology

Tuesday: November 1, 2011

Week 5: Trauma


Tuesday was our first exam. It is always a bit disconcerting when tests are open book, but I felt I did alright. Since this post is quite delayed, I can say I did more than alright, I nailed it:)


Trauma includes both intentional and accidental conditions affecting the skeleton. Antemortem trauma (occurring some time prior to death) is recognized by evidence of healing, although in some cases healing can be so complete that the trauma evidence itself is erased. Perimortem trauma (occurring shortly prior to, at, or just after death) will lack healing but usually can be distinguished from postmortem trauma (occurring some time after death, due to taphonomic processes) because living (or very recently living) bone reacts to external forces differently than dry bone.

One common type of trauma found in the archaeological record is fracturing. When a force of energy contacts bone, it will radiate in a certain pattern depending on the bone properties and the type of force. There are several key types of factors:

  • Depressed: At low velocity, these fractures will radiate in concentric rings. At high velocity, the rings are also blown by the force so only a hole remains.
  • Torsional: These are spiral fractures which occur when the proximal end of a bone is forced in the opposite direction of the distal end.
  • Longitudinal: These occur with extremely compressive forces. Greenstick fractures have a longitudinal component.
  • Transverse: Hairline fractures occur when the bone is forced to bend just slightly more than it can handle.
  • Bullseye: Technically this is not considered a traumatic fracture because this occurs when bone gets burned (as in cremation, therefore after death and not trauma).
Some fractures have special identifiers because they are seen so often:
  • Parry fracture: A fracture of the ulna, often associated with self-defense (when your arm goes up to block your face).
  • Colles fracture: A fracture of the radius, associated with falling (when you arm goes down to catch your fall).

We also discussed a little about modern trauma. Bullets can make a keyhole shaped entry with radiating fractures connected by concentric fractures. This is an incredibly simplistic description, though, because a lot of science goes into ballistics. The angle, the gun, the bullet, and the distance combine so a lot of possibilities can occur but also are related in such a way that this is how a forensic team can identify said variables. For instance, another example is a shot from the side through a leg bone. The bullet forces bone particles with it so when it goes through the other leg bone, the damage is greater (this situation is known as the Hertzian cone). People hit by cars experience both compressive and tension stresses on their leg bones, which will cave under the force and a wedged piece of bone will crack off, known as a butterfly fracture.

In bioarchaeology, everything is about patterns seen in populations. Of course there are always exceptions to any rule, but in general, pre-agricultural societies experienced more lower limb bone fractures than agriculturalists. We held class discussions with case studies to delve further into interpretation.

See other entries with similar topics:

2 remarks!

  1. You are kidding…when you get through could you become a Dr. if you chose to? Guess you would have to know all this to know what happened to the bones though when you are called to see the body of someone. Interesting.

  2. To be titled as Dr., I will have to go to another program for a PhD. The program at UIndy is a Master’s only currently.

*What is your name?

*What is your email? (Not published.)

What is your web address? (Optional)

(Required fields denoted with *.)

World Map World Map copyright 2011 and beyond