I noticed the following:
The supraspinatus PCSA is corrected with the same correction factor as it is applied for the posterior and lateral deltoid:
//The distribution of the strength on the deltoid muscle has been
//modified manually, the sum of PSCA is unchanged and according to data
//2460 mm^2
AnyVar f=0.8;
.
.
.
AnyMuscleModel deltoideus_posterior_part_1 = {
AnyVar PCSA = .f * 160.000000; // mm^2 VU study
F0 = .StrengthScaleHumerusPCSA.ConstParam.MusStress;
};
.
.
.
AnyMuscleModel supraspinatus_1 = {
AnyVar PCSA = .f * 78.000000; // mm^2 VU study
F0 = .StrengthScaleHumerusPCSA.ConstParam.MusStress;
};
.
.
.
Do you know if this was a conscious decision or do you think it is a mistake?
The PCSA values come from the same study and it is therefore necessary.
There are a few of those factors used on multiple muscles to ensure the correct values.
The reason why I am sceptical about the validity of its application is the following:
The comment defining the use of the correction factor only concerns the deltoid. I believe that it was Marta from Montreal implementing it to give the anterior deltoid (having a correction factor of 1.2) a higher weighting than than the posterior portion (correction factor of 0.8). However, she explicitly states that the overall physiological area of the deltoid muscle is conserved in order to still accord with the measurements of the VU study.
However, this is not the case for the supraspinatus. The correction factor is applied for all six fiber bundles, therefore, there is no conservation of PCSA and it now deviates from the VU study unless I miss something.
I believe this correction goes all the way back to when the model was first created at the University. However, I also think it should probably be fixed so the model follows the original as much as possible.