Questions about muscle force profiles

[DWAN (LEE DONGHWAN)]

Hello, AnyBody Team.

I'm curious about muscle force profiles in AnyBody Modeling System (AMS).

In the AMS, the muscle-tendon properties of the upper limb were modeled based on cadaveric specimens from an elderly population (Veeger et al., 1997; Holzbaur et al., 2005).

So my questions,

1. Are the muscle force profiles associated with the elderly specimens even if I used the younger subjects' kinematic data as an input?
2. If I want to calculate young subjects' muscle force profiles, do I need to modify the properties such as PCSA, fiber length, slack length, etc.?

Thank you

Best regards,
Donghwan Lee

[DWAN (LEE DONGHWAN)]

This link is helpful for my question

elderly model analysis

Hi, I would suggest you to read the following document. It may be relevant to your interests. Physical efficiency as a function of age: Development of an age scaling model for biomechanical simulation https://mediatum.ub.tum.de/doc/1173782/1173782.pdf Best regards, Moonki

[toerholm (Søren Tørholm)]

Hi Donghwan,

There is currently no age scaling built into the models, so the muscles properties does not change with age.

A specific strength value is used for the muscles. If you want a stronger or weaker person the property "StrengthIndex" can be changed please see e.g.

All BodyModel parameters — AMMR v2.4.4 Documentation (anyscript.org)

which displays this property for the arms, similarly this is available for leg and trunk.

The tendon slack length Lt0 will automatically be adjusted to the subject using the built in muscle calibration (using the default 1 parameter calibration)

If you are using the new optional two parameter muscle calibration both Lt0 and the fiber length Lf0 will be adjusted. See Lesson 5: Muscle Models — AnyBody Tutorials v7.4.3 (anyscript.org)

Best regards
Søren

[DWAN (LEE DONGHWAN)]

Dear Søren,

Thank you for your explanation.

Donghwan Lee