There are fast twitch muscles fibers in all of your muscles, especially in your legs.
You can get a twitch from stimulation or damage to the muscles.
Fast twitch fibers
Slow twitch
when muscles twitch
Often it is a mineral deficiency that causes the twitch - usually a magnesium deficiency.
fast-twitch NOT slow-twitch
Well, I'm not completely sure of this, but in my science class we were talking about slow- twitch muscles (like your esophagus for example) and fast twitch muscles (like your leg muscles). Anyway, I asked do sloths have slow twitch muscles in their legs, and he said to look it up, so I did, and it turns out they do! So the reason is they have slow twitch gastrocnemus (calf) muscles!
I think you are thinking of fast twitch muscles. There are two kinds fast twitch and slow twitch.
The twitch in your shoulder is just a twitch it does not hurt you at all:>
Because they have a faster release of energy which causes them to slow down quicker. The twitch actually refers to the fatiguability of the fiber. So, fast twitch do produce more force, but tire 'fast'er than slow twitch, which are 'slow'er to fatigue Mark, BS Exercise Science
probably, because your muscles twitch because they don't know what to do but twitch. not for long though.