Why do muscles often contract without permission? Can cramps be treated? Should you worry about twitches and tremors? Do backs actually “spasm”? What’s going on when we feel “tight” and “stiff”? Why doesn’t anaesthesia actually paralyze muscles? Is there such a thing as “muscle splinting”? And more!
It’s not a rough draft, but it’s hardly complete either: I’ve just scratched the surface of this fascinating topic, and dealt efficiently with a few prominent myths and controversies. I know I’ve completely missed some important sub-topics, and probably gotten some things wrong, and I’m sure readers will let me know.
I realized I had to write this last year while I was reading Life's Ratchet: How molecular machines extract order from chaos, from the “molecular storm” (such a cool image). I was especially motivated by the chapter about the molecules of movement and muscle:
“There is not one type of kinesin, myosin, or dynein doing one type of job. Instead, like a fleet of customizable trucks, there are superfamilies of molecular motors, with eighteen known classes of myosins, ten classes of kinesins, and two classes of dyneins.”
Muscle physiology is just bonkers. This isn’t a particular technical article, but the rabbit hole it’s built over goes deep.