Measuring plantarflexion power - Force Plate Treadmill

[Brett Baxter]

Hi All,

I am looking to measuring plantarflexion power using a force plate treadmill at a controlled walk and was wondering if anyone had any advice and/or a good paper with a strong methodology to read up about this. I am looking at the second peak on the 'm' shaped pattern at foot strike. I am also no stranger to calculating power from a force trace however wondered how to account for mass in this instance given that there will be another foot in contact with the ground during strike, thus affecting the approach in which to derive velocity from the acceleration?

Thank you in advance!

Brett

[Karl Zelik]

Re: Measuring plantarflexion power - Force Plate Treadmill

Brett, can you clarify if you are trying to compute ankle plantarflexion power (which typically involves an inverse dynamics approach that combines ground reaction force and segmental motion data), or are trying to compute power from the entire stance limb (which typically involves computing center-of-mass power, and can be estimated from ground reaction forces alone, but includes contributions from more than just the ankle). Below are links to articles that cover methods of each:

Ankle: Zelik, K. E., & Honert, E. C. (2018). Ankle and foot power in gait analysis: Implications for science, technology and clinical assessment. Journal of biomechanics.

Limb: Donelan, J. M., Kram, R., & Kuo, A. D. (2002). Simultaneous positive and negative external mechanical work in human walking. Journal of biomechanics, 35(1), 117-124.

All the best, Karl

[Brett Baxter]

Re: Measuring plantarflexion power - Force Plate Treadmill

Hi Karl,

That is great thanks a lot for your suggested papers! I am trying to avoid an inverse dynamics approach and just use GRF solely.

Thanks Again!

Brett

[Karl Zelik]

Re: Measuring plantarflexion power - Force Plate Treadmill

No problem. Sounds like you want to use the individual limbs (center-of-mass power) method described in that Donelan 2002 paper. In case it is helpful, there is a Matlab script in the toolbox here that performs this calculation based on ground reaction force inputs: https://my.vanderbilt.edu/batlab/res...tion-analysis/

[Brett Baxter]

Re: Measuring plantarflexion power - Force Plate Treadmill

That’s great and extremely useful, thank you so much Karl!