PLOT interpretation and explanation

[Daniel Rossi]

Hi everybody

I'm wondering about a simple plot, if I suppose the correct interpretation.

It's a simple test about Bicipes tendon force vs elbow flex (0 - 130 degree).

test1.tiff (62.76 KiB) Viewed 308 times

test2.png (12.23 KiB) Viewed 308 times

In position 0 degree, the force is equal to 600 N. This means tendon force of that part of muscle (Bilong) can develop F=600 N.
Supposed: [ F = m* a ]

Is F direction along tendon lenght, right?

Are m and a reported to the muscle part connected to the tendon ?

So if I sum all bicipes muscles in the model (3 types) , I get in the same position F = 2000 N. Is it not too much comparative in real life ?

test3.png (13.78 KiB) Viewed 308 times

thanks very much in advance.

[Thomas Uchida]

Is F direction along tendon lenght, right?

Yes.

Are m and a reported to the muscle part connected to the tendon ? So if I sum all bicipes muscles in the model (3 types) , I get in the same position F = 2000 N. Is it not too much comparative in real life ?

Whether a simulated muscle is unreasonably strong also depends on the muscle's path, since the ability of a muscle to generate a joint moment depends on its moment arm. Please see "What is a moment arm? Calculating muscle effectiveness in biomechanical models using generalized coordinates" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4404026/) for details.

[Pauline Verdier]

Hi,
in the plot "biceps Force vs Elbow extension" I don't understand why the curve decreases from 60

I have the same question for the curve "tendon-force vs flexion" in tuto 2.


thanks very much in advance.