Hello everybody,
I am currently working on a gait model with motion capture data and pressure insoles. I applied both into Anybody and the calculated knee reaction forces seem to be too high (as well as the forces from other joints). Especially the Anterior posterior force goes up to 600% BW and the Proximo distal force also increases up to 1.000% BW. My research showed that normal joint reaction forces in the knee while walking should be around 200-280%BW in the Proximo distal direction and only around 20% BW in the Anterior posterior direction.
I checked problems with the reference frame, applied the same model in a newer version and checked the applied ground reaction force, but didn’t find a problem. Some help or ideas would be great!
Thanks in advance,
Regards
Tabea
Hi Tabea,
Here are the things I can think of in this situation:
- is sync between mocap and pressure ok
- have you checked the applied pressure forces magnitude? does it resemble GRF predictions from same model.
- Pressure by nature does not have friction, how did you deal with this? if you have applied the pressure "forces" as vertical forces acting from ground to foot it will create a strictly vertical force to the foot. This will create very high forces in the joints because the resultant GRF is pointing straight up and not in any way aligned with the joints which is normally the case.
Do you have full-body mocap to drive the model, this would be useful to predict direction of GRF?
Best regards
Søren