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The week in Biomechanics #CW15: Easter special

Lasse Hansen 0

Last updated on April 14, 2020

The weekly recap of what is going on in the world of biomechanics.

  1. Easter Biomechanics
  2. National Biomechanics Day & Delsys, Inc. Donation
  3. ISBS Lecture Series (No. 5)


Although not published very recently, this week we will talk about a paper dealing with a rather rare topic in biomechanics: Rabbits. Secondly, we will present a very interesting paper published last week in the Journal of applied Biomechanics which discusses the effects of visually augmented gait training on the risk of tripping related falls. Enjoy reading!

Rabbit Knee Joint Biomechanics: Motion Analysis and Modeling of Forces During Hopping:
When rabbits are being mentioned in biomechanic publications, those are usually studies concerning osteoarthritis, bone growth and fracture healing. Rabbits are advantageous for these research topics, because they remodel their cortical bone similar to humans (have a look at the paper by Grover DM, Chen AA, Hazelwood SJ if you want to read more). But in this paper, two researchers from the University of Rochester (NY, USA) had a look at the in vivo biomechanics of the rabbit knee joint during hopping. For this purpose, they gathered force platform data and 3D motion analysis data using infrared markers on intracortical bone pins in order to develop a model to estimate the joint contact force distribution between the tibial plateaus.
They found that during hopping, the prevalence of an external abduction moment led to the prediction of higher joint contact forces passing through the lateral compartment as compared to the medial compartment of the knee joint.
This was the first published data on rabbit in vivo kinematics, and surely there is a lot more to find. But still this is an interesting outcome, since it may provide further insight on the pathomechanism of osteoarthritis in humans, given the structural similarity of the bone.

But for now: Happy easter!

Gushue DL, Houck J, Lerner AL. Rabbit knee joint biomechanics: motion analysis and modeling of forces during hopping. J Orthop Res. 2005;23(4):735–742. doi:10.1016/j.orthres.2005.01.005

Grover DM, Chen AA, Hazelwood SJ. Biomechanics of the rabbit knee and ankle: muscle, ligament, and joint contact force predictions. J Biomech. 2007;40(12):2816–2821. doi:10.1016/j.jbiomech.2007.01.002

Effects of Visually Augmented Gait Training on Foot-Ground Clearance: An Intervention to Reduce Tripping-Related Falls:
Tripping-related falls are a large risk for the elderly, and one factor influencing this risk is the minimum toe clearance (MTC). That is an event during gait at mid-swing, characterized by a low clearance between toes and ground (10-30mm) and high foot velocity (around 4.60 m·s−1). In this experiment, 10 young (23±2 yrs) and 10 older (77±9 yrs) walked on a treadmill and were able to see direct feedback about their MTC on a screen. For ten minutes, they walked at a self selected speed without MTC information (baseline), subsequently a twenty minute walk was conducted with MTC information (feedback). Finally, the participants walked for ten minutes without feedback again (retention).
The researchers did not find aging effects in baseline (young: 12.7±2.6 mm; older: 14.2±3.5 mm) and feedback (young: 28.8±5.1 mm; older: 27.5±8.7 mm) condition. For both groups, the retention MTC was significantly higher (young: 40.8±7.3 mm; older: 27.7±13.6 mm). The joint angles of the young during the retention condition indicated that they used an increased ankle dorsiflexion at toe off and modulated knee and hip angles later in swing.
Altogether, these findings indicate a positive effect of visually augmented training, although the sustainability of these effects would be interesting to see in a succeeding study.

Straaten, R., Tirosh, O., Sparrow, W., & Begg, R. (2020). Effects of Visually Augmented Gait Training on Foot-Ground Clearance: An Intervention to Reduce Tripping-Related Falls, Journal of Applied Biomechanics, 36(1), 20-26. Retrieved Apr 10, 2020,

National Biomechanics Day

Last Wednesday (8th April 2020) on the 5th (inter)national Biomechanics Day, the world celebrated the breakthrough science of the 21st century. Many of the activities planned around the world for pupils and students had to be cancelled due to the current COVID-19 situation. Nevertheless, many scientists drew attention to their research online or remembered eventful past Biomechanics Days.

The NBD was founded in 2016 by biomechanics enthusiast Dr. Paul DeVita and is intended to inspire the younger generation for this field of science. In general, anyone who is interested in biomechanics can register and implement their own ideas locally. This will also happen this year – all activities will be postponed until October.

Delsys, Inc. donates $60,000 in equipment + funds to support the biomechanics scientific community

Delsys, Inc. took the NBD and the current COVID-19 situation as an opportunity to donate equipment, software and money to scientists, PhD students and students. Applications are accepted until Tuesday, April 14, 2020 under this link.

ISBS Lecture Series (No. 5)

Also this week another part of the Sport Biomechanics Online Lecture Series of the ISBS took place. This time Dr. Wouter Hoogkamer spoke about footwear sciences and about making Eliud Kipchoge’s under 2 hours marathon possible. In this extremely exciting lecture, especially for those interested in running, the biomechanist reported on general life experiences, fake news and above all on the mechanics and physiology of running as well as on the latest technology in running shoes. We were particularly fascinated by his enthusiasm for running science and his competence in biomechanics.
If you have not yet seen this issue, you should definitely make up for it:

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