TL;DR: I need more information on the mechanical properties of human skeletal muscle; if you have such information, please give it to me.
I'm writing something on how much more effective (or otherwise) spider silk would be as a muscle and/or connective tissue in prosthetics in in comparison to human skeletal muscle and connective tissues. As such, I need information on several of the mechanical properties of human skeletal muscle, such as its:
- fatigue limit; this is particularly irritating to attempt to find info on; looking it up instead gets returns on the entirely unrelated concept of muscle fatigue, even with very specific search terms.
- ultimate tensile strength; while I have sources for this, they're inconsistent, giving me values between 0.44 MPa and 5.3 MPa - more than an order of magnitude in difference!
- tensile and/or compressive (i.e. end-to-end/lengthwise) Young's modulus; I already have information on its transversal (i.e. perpendicular to a strand) Young's modulus, which, from what I can tell, is another word for shear modulus, and therefore is useless for my purposes; after all, good muscles are, AFAIK, supposed to withstand tensile or compressive loads, not the shear ones discussed in that source.
- elastic modulus; I already have information on it after 8 days of cell differentiation (45.3 ± 4.0 kPa), or the elastic modulus of the rectus femoris in particular (16.67 to 85.31 kPa, depending on pressure applied), but these sources contrast with one of my sources for skeletal muscle's ultimate tensile strength, which states that this figure is 36 ± 19 MPa.
I was also able to find another source on its Young's modulus, but it doesn't specify the direction the Young's modulus was measured in.
One of the few sources I currently cannot find problems with are this one, on how much a strand of muscle can elongate before it fails - and that's because I can't find any other sources which could contradict it - and this one, on how much force a longitudinal muscle of a certain cross-sectional area can contract with: ~30 newtons per square centimetre, or 300 kPa.
...although I'm still trying to figure out which parts of it correspond to which points on a stress-strain curve.
The unifying factor here, however, is that I don't have enough sources - so few, in fact, that I have no reliable information on the fatigue limit. Please give me more.