Hi Tim
Looking at the hip reactions reported in the literature there is
considerable variation
In the paper by Bergmann et al [1], the reported forces peaks reach values
up to 324% BW for 4 km/h gait , and 467% BW for one subject walking at 3
km/h
Brand et al [2] has values reaching also about 325% BW, I am not sure for
which speed.
[1] G. Bergmann, F. Graichen, and A. Rohlmann, “Hip joint loading during
walking and running, measured in two patients.” J Biomech, vol. 26, no. 8,
pp. 969–990, Aug 1993.
[2] Brand, et al. (1994) J. Arthro. 9(1)45-51
So I think the results of the model will reflect this, there will be a wide
variation depending on the particular load case applied.
Please also have a look at these videos:
Walking speed 3 km/h
http://www.orthoload.com/files/video/result/ebl4628b_screen.wmv
Walking speed 4 km/h
http://www.orthoload.com/files/video/result/ebl275c_screen.wmv
Here you can see forces reaching up to 337%BW
I am not sure which data has been used for the graph in the webcast, sorry.
I do not think there is a current effort to replicate some of the Hip98
experiments, but it would be really nice to do this.
Please be aware that the new repository7 contains a new gait model
GaitUniMiami which motion is created using an external application
GaitApplication2, please see posting #2159 by Michael Skipper Andersen. In
the GaitUniMiami model there is a 15 step procedure on how to create a model
based on a C3D file, I am mot sure if there is C3D files available for the
Hip98 data, but it would still be possible to do the model using the
GaitApplication2, as long as you can get trajectory files for each marker.
Please write again if you have further questions
Best regards
Søren, AnyBody Support
From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
Of timwehner
Sent: 16 June 2008 17:59
To: anyscript@yahoogroups.com
Subject: [AnyScript] Hip contact forces of Gait3D
Hi everybody,
my name is Tim and I’m currently working at the university of ulm,
germany.
The reason for using the AnyBody software is to get the internal
loads of the muskuskeletal system during daily activities.
Therefore I’ve used the Gait3D model from the Repository 6 and
compared the resultant hip contact forces with the in vivo data given
by Bergmann et al. on the HIP98 CD.
The Gait3D model showed much higher contact forces as already
mentioned in the webcast of Catherine Manders from 29. January 2008.
In the webcast of J. Rasmussen (Gait Modeling, 31. August, 2006)
there was mentioned that the change to another set of GRF improves
the hip contact forces alot.
Due to this, I’ve some qeustions:
-
Are the higher hip contact forces with the dataset of Vaughan
unphysiological high?
-
Which GRF values were used for the simulations showed in the
webcast “Gait Modeling”, that led to improved hip contact forces?
-
Are there efforts taken to simulate the patient specific gait
patterns from the Hip98 CD to get the opportunity to directly compare
the hip contact forces with the in vivo measurements for validation
purposes?
Best regards,
Tim
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