Join reaction forces in gait analysis

Hello everyone,

I am currently working with Anybody using the Full body Gait model. I manually added the ground reaction forces via a .txt file instead of using force plates, because we used pressure insoles. Everything worked fine, but the resulting joint reaction forces for the joints of the lower limbs seem to be way too high. They reach up to 5.000N and, if i read correctly, should be around 800-1.000N.

Is there a common mistake I made or is my research about "normal" joint reaction forces wrong?

Hi Tabea,

I can think of a couple of issues:

  1. With the pressure mat, you get the normal force. How are you taking care of the ground reaction force in the medial-lateral and anterior-posterior directions?
  2. Have you checked that the forces you are inputting in the model are sensible? Are they comparable to what you would see if you had a force plate?

Best regards,
Dave

Hi,
Thanks for the quick answer!

  1. I am using pressure sensing insoles, and only recieve the force in the proximo-distal direction. I am not using the forces in medio-lateral or anterior-posterior directions
  2. The ground reaction forces are different in each person but are around 700-1100 N per leg (because of a tibial fracture the other leg is recieving less froces around 0-500N)