Hello again, welcome to the third video of the paleopathology module. This video is about skeletal trauma. You probably think right away of bone fractures, that is a partial or complete break in a bone. This figure shows one way of categorizing the different causes and types of bone fractures. And in the online discussion forum, you will find a question asking if you've broken any of your bones. Either as a child or an adult. But there are other types of traumatic injuries, that we can sometime see in the skeleton. Including when a bone is permanently or at least very frequently dislocated or displaced when nerve and/or blood supply is disrupted for a long period of time causing the bone to atrophy, or even artificially induced changes to a bone's normal shape, such as caused by artificial cranial deformation. Corsets or foot binding. Now, we think of such practices as having accord only in the past but is that really true? Think about it, there are a lot of cultural practices undertaken today that have a significant effect on the shape of your skeleton. This is another topic for you to discuss on the online forum if you'd like In past peoples we often find evidence of trauma. Most often via broken bones in various states of healing. And we will focus on bone fractures in the first part of this video. In the second part there is a case study about cranial gunshot trauma. The type, location, state of healing, prevalence, and age and sex distribution of bone fractures, provides osteoarchaeologist with evidence for a number of things. For example, fracture patterns can tell us about the types of activities a person was engaged in. It's easy to imagine that a world crop farmer would be exposed to a difference range of activities than a business person living in a city. So resulting in a different risk for different fractures and in different areas of the bone. You could also imagine that different activities might be engaged in, for example by hunter gatherers, versus agriculturalists, men versus women, sailors versus people living inland. And finally, with fractures and other traumatic injuries osteoarcheologists can often detect episodes of violence in the past. A broken bone undergoes four stages of healing, depicted in this figure. This is important to know, because it gives us an idea of the stage of healing and that's how long ago a break occurred to briefly explain what you see in this figure. Upon initial injury, torn arteries release blood into and around the fraction site which soon clots. This is called a hematoma. During this time the bone cells around and outside of the injury site die. And after two to three days, the blood clot is invaded by capillaries and fibroblasts and then bone forming cells. By one to two weeks later these cells had deposited collagen and fibrocartilage and this forms a soft callus. Soft because it's not yet mineralize. By as early as three weeks and as late as three months later. The soft callus will become mineralize forming a hard callus. Made first of immature woven bone and later of remodel lamellar bone. The final stage is by far the longest, taking up to seven years. And it consists of the gradual remodeling and realignment of the bone. Which if the fracture was set properly, can eventually lead to the disappearance of any evidence of the fracture. The amount of time this takes will vary based upon a number of factors including the fracture type, bone area, age of the individuals so children heal much more quickly, if there was infection, mobilization and one's nutrition. Now that you have a basic understanding of how bony fractures heal, you can watch a short optional video which shows you a few examples of bone fractures from our laboratory. In the second part of our video we're going to look into a case study about a very specific type of trauma. That is penetrating high velocity injuries to the skull caused by bullets. Most of you will now think of gunshot wounds made by high caliber firearms like in a modern forensic case. This case study, however, is a bit different. The setting is the Dutch city of Alkmaar, shown here. And the event occurred in 1573 during a siege of the city during the Eighty Years' War between the Spanish and the Dutch. Rachel, welcome. Thank you for joining us today. >> Thank you for having me. >> So tell us about what you were excavating in 2010, and what led you to conclude that you had uncovered victims of the Siege of Alkmaar. >> In 2010, we were excavating at the Paardenmarkt in Alkmaar. This use to be the site of the Franciscan Friary with associated cemetery. On this site we completely, unexpectedly also founds 2 mass graves, containing 9 and 22 individuals. The dating of the graves as well as the medieval bullets we found associated with it led us to believe that we had uncovered victims of siege of Alkmaar in 1573. The demographic composition of these two mass graves was quite different. The smaller one, with nine individuals contained both men, women, and children of all ages. Considering this we thought this might be the civilian victims of the siege. The larger mass grave, 22, only contained young male individuals. And this let us then to believe that these might have been the soldier victims of the siege. >> Hm, very interesting. So then, tell us about the cranial trauma that you observed in the skeletons. >> Yes, when we indeed brought the skeletons back to our lab, we quickly found that four of the individuals sustained cranial trauma caused by bullet wounds. This individual, from the smaller mass grave, shows clear signs of cranial trauma caused by bullets. So here you see an entrance wound and here you can see the exit wound. Since the cranium consists of and outer table and an inner table, the exit and entrance wounds can be quite easily distinguished. Here you can see the entrance wound and on the inside you'll see internal beveling which is caused by the bullet traveling at this direction Inside of the skull. On this side the exit wound you will see the same process but then on the outside of the skull. The bullet travels this direction through the skull and comes out here. And this is called external beveling as a result of the bullet traveling outward and flaking away little pieces of bone. >> Very interesting. So from this larger mask rave, did the young adult males have other pathological lesions that might suggest they were indeed soldiers? >> In addition to the sex and the age of the individuals, which is all ready quite indicative, we also found other pathological legions which would be suggested for them being soldiers. Many of the individuals sustained trauma in their spine as the result of degeneration of the disk. This you can actually see quite well on the bones. And this happens normally in older individuals but here we also saw less in the other lessons and then in younger adults which is quite uncommon. And is suggestive of them performing physically demanding tasks or carrying a heavy armor, for example. Additionally, we found antemortem trauma, more than you would normally find this in a cemetery. We found that several individuals had broken ribs which were completely healed over at the time of their death. In addition, there was one individual with healed sharp force trauma. Apparently, this individual was struck on its head with a blade. And this had completely healed at the time that he was actually shot as well and ended up in one of the mass graves. This, together with the age and the sex of the individuals, led us to believe that these were indeed the soldier victims of the siege of. >> Wow, what an amazing discover. Rachel, thank you very much for joining us and taking the time to explain to us your research. >> You're welcome. >> There's a final component of this research that we will tell you about today. I'm pleased to introduce Professor Dr. Menno Hoogland. Prof. Hoogland is Rachel Schats' PhD supervisor and he directed the forensic reconstruction research that was undertaken to better understand the ballistic, the gunshot trauma, that was seem in these individuals. Professor Hoogland, could you please tell us about that research? >> Yeah, sure. So from historical sources we know that the weapon of the Spaniards was the Arquebus. And that is an 18 millimeter caliber weapon, shooting heavy bullets out in the range of 35 to 40 grams. In the first place, we were interested to replicate the trauma has shown in the Crania from Alkamaar And in the second place, we were interested in verifying the distance between the shooters and the victims. >> Hm, interesting questions. And so, what exactly did you do? >> So we contacted the Netherlands Forensic Institute. And in the Institute, Rob Hermsen is the ballistic expert. And with rope we made a experimental setting for this research. So he was shooting with a modern weapon, and but charged with a old fashioned round 35 grams bullet. And then, the target was this thin bone replica skull, and we recorded the experiments with a high speed camera. >> Hm, interesting. Okay, and so what was the outcome? >> So we could indeed confirm that the weapon was the and that the velocity of the bullet was pretty slow. It was only 100 meters per second. If you compare that with a modern weapon and that is in the range of 500 to 900 meters per second. So that is really, really slow. And such a weapon as soon as the bullet has speed, and then it will continue, continue, continue until it drops down by gravity. And we could confirm that indeed the distance was in the range of 30 to 80 meters. And if you compared that with details on the 16th century painting in Alkmaar Museum, showing the siege of the city, then indeed you can see that the distance between the shooters and the soldiers on the city wall is about in the range of 50 meters. >> And what did you see on the simbow replica? >> Yeah, what you can see here is the entrance wound. Here, you see the same beveling as the racka shown on the train of Alkmaar and the same pattern of fracture. However, the exit wound is different and the dent is different because the replica's skull is filled with ballistic gelatin and the gelatin is behaving different than our brain tissue. >> Very innovative and very informative research. Professor Hoagland, thank you very much for joining us today. >> My pleasure. >> In this video, you've learned about a sub field of paleopathology, skeletal trauma. Now you know the basics about how a fracture heals. And you've seen an interesting case study about gunshot trauma from the war that occurred over 400 years ago. Has this left you curious for more? Would you like to see how a lack of Vitamin D, the sun vitamin, can affect your skeleton? And the ways that this can tell us about how people lived in the past. If so, stay tuned. Next, we will explore a disease called Rickets.
