Falling and Slipping

Hi everybody,

Im starting a project and the general idea is to modulate a human fall/slip. I really need to know if it is possible to modulate it with anybody. If its possible, i can use tracking technology to duplicate the movement or do i have to create it ? I intend to use a full body model.
As you can see, im new at anybody community :).

With the best regards,

Hi Marco,

Welcome to the forum,

In relation to slip fall analysis the following notes should be made: AnyBody uses inverse dynamics so motion is input to the model. So you need to measure the slip motion, you will also need to measure the GRF. There are no activation dynamics in AnyBody, so in the analysis it will be possible to activate a muscle instantly whereas in reality when the slip occurs the muscle may not have time to react as they will do in the model. This may impact the results depending on the speed of the slip etc…

If you look in the reference list there is a paper related to forces in the lower spine in relation to slip please see:
Rashedi, E., Jia, B., Nussbaum, M.A. & Lockhart, T.E. (2012), “Investigating the effects of slipping on lumbar muscle activity, kinematics, and kinetics”, Human Factors and Ergonomics Society 56th Annual Meeting. [DOI]

Please ask again if you have further questions,

Best regards

Hi Søren,

Thank for your quick reply.

I’m going to use xsens to gather the movement information as well ass all data as acelaration, velociti and position.
I intend to get the bones reaction forces, muscle reaction forces and muscle activations are secundsry, but if I can get all the information better.

One more time thanks for you quick reply, and I will give some feedback.

With best regards,
Marco Marques.


I’m trying to create a methodology in order to create the model using the MoCap template, and i have a serious question.

  1. I want to evaluate the ground reaction forces on the knee, hip, elbow, wrist and shoulder in the fall. To do this i need a force plate, right?

  2. I want to attach to those locations some kind of foaming protections with specific geometry. Will i be able to export the model with those location with those measured reaction forces to ABAQUS? i now that forces that muscles do in the insertion point are likely to be exported, but i need to know if i could export ground reaction forces and muscle activation forces

Thanks again and sorry for any less “smart” question.

Dear Marco,

Are you interested in the forces that appear during the impact?

You can simulate that kind of motion, but the muscle recruitment solver is not made for such motions.

If you record the forces on knee, wrist etc, you can also analyze the joint moments and forces. But as mentioned before, the muscle activation will not give proper values.

What do you want to analyze in Abaqus? Usually, you export one segment, eg a tibia with all forces acting on it to FE. Meaning you have in Abaqus the tibia, with joint reaction forces from ankle and knee and muscle forces from all attached muscles. If you measure the ground reaction force on the knee for example, you can add them as additional loads in your FE model.

Dear Amir,

Yes, I am interested in the forces that appear during the impact. Muscle recruitment, isn’t critical. I’m most interested in the forces on knee, wrist etc. The problem is that i don’t have any force platform to obtain the ground reactions.

Best regards,
Marco Marques

Hi Marco,

You can analyze the kinematics in AnyBody (wihtout muscles), including the fall and impact, but you cannot predict the impact force in AnyBody:

Welke, B., Schwarze, M., Hurschler, C., Calliess, T. & Seehaus, F. (2013), “Multi-Body Simulation of Various Falling Scenarios for Determining Resulting Loads at the Prosthesis Interface of Transfemoral Amputees with Osseointegrated Fixation”, Orthopaedic Research Society. [DOI]

Schwarze, M., Welke, B., Seehaus, F., Schmalz, T. & Hurschler, C. (2011), “Stress Resultants in Proximal Femur of Transfemural Amputees During Different Cases of Falling: A Multi-Body Simulation”, , pp. 1 p., Poster presented at the DGfB Murnau May 2011, Germany . . [PDF]

find the links here: http://www.anybodytech.com/index.php?id=publications#c1214