Hello everyone and welcome back. Well for starters let me just say this will be my last post about the salamanders. I hope that you enjoyed and learned something from reading my blog these last few weeks. Hopefully, I inspired you to do more research on the salamander or even start your own blog on this species. But enough of that lets dive right into this week’s topic.
This week I found a research article that focused on the limb bone stress and loco-motor forces during the movement of a Salamander. Specifically, the researchers focused on the femur of the Tiger Salamander. Before we go deeper into the article, I listed a few words below with the definition so it can be easier to read.
- Ground reaction force (GRF)- the force exerted by the ground on a body in contact with it.
- Locomotion- the movement or the ability to move from one place to another place.
- Femur- a bone of the thigh or the upper hind limb.
- Ectothermic- any cold-blooded animal or an animal that regulates its body temperature.
- MATLAB- a programming language and numerical analysis environment that include matrix calculations, and data visualizations.
In this research, the authors had two hypotheses. One being that the salamanders exhibit low limb bone loads and high safety factors like ectothermic, non-avian replies and that torsion is a prominent loading regime in the salamander femur as in other species that use sprawling limb posture (K.M. Sheffield and R.W. Blob).
The researchers used a total of five adult Tiger Salamanders, 3 females and 2 males, and persuaded each salamander to walk in place by gently squeezing its tail. With the help of modern technology, the researchers were able to slow down the footage of the footsteps and record the data from the plate. Several graphs were made to show the lateral and posterior view of the GRF. the mean for the femoral bending factor was also calculated the worst being at 4.5 and the best at 10.5.
In summary, the findings using a tiger salamander confirmed the most broad patterns found in other tetrapod lineages. The safety factors were at about 10.5 in bending which is a little higher than other salamanders and suggests that salamander femora might help the variability in femoral stresses.
This founding now helps support the broader hypotheses of limb bone stress in other tetrapods. I thought that this experiment was interesting for two reasons. First off, I have never seen anything like this before so I just thought it would be interesting to read. Secondly, I think that if I understand how something this simple (not really simple, actually very complicated) it would be easier for me to understand the different stresses and movements of the human body.
Well, guys, that’s it. We have officially come to the end of our Salamander journey. I hope you guys enjoyed my blog as much as I enjoyed writing it for you!!!
K. Megan Sheffield, Richard W. Blob
Journal of Experimental Biology 2011 214: 2603-2615; doi: 10.1242/jeb.048736