bike kinetic

[Marco Freddolini]

Hi,
I am doing a research about cycling. I have two pedal dynamometer with 3-D load cell and i am using VICON for kinematics of the subjects and pedals. do you have a MATLAB code for the inverse dynamic that i can use with the pedal to get hip, knee and ankle moments?
Thanks

[Dan Robbins]

Re: bike kinetic

Hi Marco,

I am just starting to look at this too, currently I am working through the following reference:

Hull and Jorge (1985) (A Method for Biomechanical Analysis of Bicycle Pedalling, Journal of Biomechanics. Vol 18; 9 p 631-644)

I have not produced working code just yet, therefore if you have any success I would be interested in hearing your methods/seeing your code. On the other hand if I manage to get some working code together I will be happy to share.

Regards
Dan

[Eneko Fernández Peña]

Re: bike kinetic

Hi Marco and Dan,

the ISB webpage has a 2-D Inverse Dynamics benchmark data and a MatLab code for this purposes (http://isbweb.org/data/invdyn/index.html). I found it very helpful, even if I use Excel VBA programming rather than MatLab.

Dan, the Hull and Jorge (1985) method that the hip joint remains constant, which is not necessarily true in cycling.

Hope this helps,

Eneko

[Natalia Dounskaia]

Re: bike kinetic

Hi Marco and Dan,

When it comes to analysis of the computed moments, I recommend the article by Raasch CC, Zajac FE. Locomotor strategy for pedaling: muscle groups and biomechanical functions. J. Neurophysiol. 1999; 82(2):515Y25. They show that there are four phases in cycling. During two of them, uniarticular hip muscles generate energy for the entire movement and the ankles transfer this energy to the crank. During the other two phases, biarticular thigh muscles generate energy and the ankle transfers it to the crank. This is a functional interpretation consistent with the leading joint hypothesis (Dounskaia N (2010) Control of human limb movements: The leading joint hypothesis and its practical applications. Exercise and Sport Sciences Reviews, 4: 201-208, review). It may be useful for you because it clarifies the role of each joint in the production of the entire action in a simplified way, facilitating practical applications.

Natalia Dounskaia

[James Shippen]

Re: bike kinetic

Hi,
I am doing a research about cycling. I have two pedal dynamometer with 3-D load cell and i am using VICON for kinematics of the subjects and pedals. do you have a MATLAB code for the inverse dynamic that i can use with the pedal to get hip, knee and ankle moments?
Thanks

You can use BoB, a biomechanical modelling package for Matlab/Simulink, which will give you the joint torques, joint contect forces and muscle loadings. BoB can be downloaded from www.marlbrook.com/download

[Dan Robbins]

Re: bike kinetic

You can use BoB, a biomechanical modelling package for Matlab/Simulink, which will give you the joint torques, joint contect forces and muscle loadings. BoB can be downloaded from www.marlbrook.com/download

Hi James,

Thanks for the info, I looked at an older version of BoB where it was not possible to import data in *.c3d format. Is this now available and if not what format should data be in when loading into BoB?

Thanks again
Dan

[James Shippen]

Re: bike kinetic

Hi Dan

Is the motion data captured with a Vicon system? If so, I can provide a BodyLanguage script to calculate full body joint angles suitable for input to BoB. If you didn't use a Vicon and only require lower body analysis, calculate the hip, knee and ankle angles (as a Matlab user this shouldn't be too difficult) and these can be easily input to BoB in the Simulink environment. If you want full body analysis that will obviously require a bit more number crunching inn Matlab but very do-able (a re-working of the BodyLanguage scipt into M-code might the way to go). I also have written a BVH to BoB converter if that's of any use.....?

Or you could use BoB's inverse kinematic solver to calculate the joint angles from positions of the seat, pedals and handlebars.

All the best

James