[asd4]

It's a single axis version of a system my group at NASA developed:

https://roundupreads.jsc.nasa.gov/pages.ashx/787/New%20weara...

The internal application was to improve mobility in space suits. We had a partnership with some medical researchers looking to help patients with otherwise limited mobility.

Shoulders are difficult. The human body has a lot of amazing degrees of freedom. One of the biggest challenges was efficient and effective transfer of the assist forces to the body.

[marginalia_nu]

A lot of the design of the human body sacrifices strength for mobility and range of motion. Most muscles have really unfortunate mechanical leverage, to the degree it's quite impressive we're so strong as we are.

Adding to that, without completely butchering mobility is probably no easy task.

[samatman]

What's remarkable to me about this is how specialized our shoulder-arm linkage is for overhand throwing.

A lot of the typical difference between the male and female upper body comes down to this specialization. There is some evidence of facial adjustment to punching, but we could hit much harder with a more chimp-like shoulder, this doesn't require knuckle walking: but we wouldn't throw a spear as far nor as accurately.

[2-718-281-828]

I'm also impressed everytime I lift weights and think about how close the muscles attach to the joint providing very little leverage. On a side note - this is why chimps f.x. are so strong - their muscles attach further from the joints and by that provide more leverage.

[silicon2401]

> chimps f.x.

Just a small note, that abbreviation seems extremely rare to me. You might have better readability by saying "e.g." which means the same thing, or just writing it out. It took me a while to figure out whether you were referring some body part belonging to chimps or something

[pinkmuffinere]

Wow even after reading the above comment I still can't confidently piece together what "chimps f.x." means. Is it "chimps for example"?

[2-718-281-828]

seriously? I speak internally while writing and "for example" feels more fluent than "exempli gratia". that's why I prefer fx. I'm not a native speaker, though

[kernelbugs]

Another native speaker chiming in. This is my first time encountering f.x. and it took me quite a while to figure out (essentially guess) what it meant. Most people I know and situations I've encountered use e.g. (possibly without even knowing what it means). In common usage e.g. is "for example" just like etc. means "and additional things" or i.e. means "that is".

[gknoy]

I wish I could write or speak another language anywhere close to as well as you do English.

You're right! I certainly don't think of the words "exempli gratia" -- I literally think the letters "e g" as a mental shorthand for "for example". I often find myself writing "e.g." first, and then expanding it to "for example" when re-reading what I wrote.

Sorry. English is weird. "f.x." seems like it should be a preferable abbreviation for "for example", but it just isn't idiomatic. I figured out that was what you meant when reading it, but it definitely stood out in much the same level of wrongness as seeing code that isn't formatted correctly or that uses a non-idiomatic way of doing things (list comprehensions in Python).

[Cthulhu_]

I always thought e.g. meant "example given"; there's also "i.e." which I presumed meant "in example".

anyway, "for example" takes two seconds to type (if that), if abbreviations cause confusion (in general, in any situation, especially professionally), avoid them.

Anyway I'll brb, I got an I&A meeting for our SAFe procedure, gotta get our CI's and DoD in order and make sure we execute LCM properly. No I don't know what any of these abbreviations mean, but this is the situation we find ourselves in, lmao

[MaKey]

I'd suggest sticking to "e. g." as well. I'm also not a native speaker and have never seen the abbreviation "f. x." before so I couldn't figure out its meaning.

[silicon2401]

If you know what e.g. stands for, you don't need to expand it. Native speakers just say "e.g.", as in, "ee gee". If you don't know what "fx" stands for then how would you expand it? It's not a common abbreviation at all

[mgdlbp]

FWIW the abbreviations listed in Wiktionary are f.e. and f.ex.

[moffkalast]

chimps: f(x) = y^2

[belfalas]

Depends on where in the world you hail from originally. I have also seek "fks" to mean the same thing. More common with non-native English speakers.

[silicon2401]

It's probably a feature of non-western English varieties. I've never seen "fks" used to mean "for example" and would never imagine that that's what it stands for.

[tomjakubowski]

Yep, and they vary somewhat from person to person. I think it's part of why some people are apparently stronger than they look: longer tendons give more leverage with less muscle mass.

[kenjackson]

Is there any advantage to having muscle attachments closer to the joint?

[Tuna-Fish]

Range of motion. You can pick up a stick, hold it above your head, and throw it with significant power and control. A chimp can't do that.

[kenjackson]

I was thinking more within human variances. For example, I've seen athletes with high calf muscles who can jump really high. If there an advantage to those whose calf muscle stretch to the bottom of the leg? Do they have some increased range of motion that this helps with?

[HPsquared]

That's probably the secret of the shoulder, it's strong(-ish) in some directions and very weak in others.

[krferriter]

And why people dislocate their shoulders so frequently, just doing like normal things. Someone I knew dislocated his shoulder swimming freestyle. Just happened.

[youamericanloo]

I think yours is multiple axis version of this one since this the topic ...