So I’m sitting her about to read the latest SDMB threads. I’m in a nice comfortable chair. Relaxed.
All of a sudden a set of muscles in my left thigh, a bit about the knee (and to the left) start a rhythmic twitch. This is not something bare imperceptable. Looking at my bare thigh (I’m wearing shorts) I can plainly see the muscle fibers contracting/relaxing again and again.
No, I’ve haven’t just come in from exercising. I’ve been in this chair about 45 minutes doing paperwork and reading online news.
So what’s happening here? This has happened before to muscles in my legs, arms, even my torso.
I hope it’s OK to jump in, even though I don’t have a definitive answer for you. However, I get this exact same thing sometimes, and I associate it with either being low on fluid or off in my electrolytes - I’ll drink a big glass of water and/or have a banana, and the symptoms will eventually go away. I’m not sure if I’m actually addressing the problem, or it’s just the passage of time.
Now, I’ll sit back with you and see if someone who knows what they are talking about wanders through this thread.
If you don’t mind, I’d also like to ask a similar question-- what is that mighty contraction feeling I get in my thighs sometimes when I sit down after exercising? I don’t have it now, so it’s hard to recall the exact situation, but it feels like a cross between a pulse and a muscle twitch. If it’s just blood coursing excitedly through my system after increased heart rate, why does something similar not happen in my neck?
Sometimes these rythmic twitches can just be a symptom or general tiredness - either physically, from recent exercise (I know you said this wasn’t you), or just from hunger or lack of sleep; I get them routinely in my leg and arm muscles, but they’re worse when they happen in facial muscles around the eyes.
They usually stop if you slap them, but this cure is sometimes worse than the ailment.
I’ve been getting these since I was a kid, typically in the limbs, but sometimes around the face, too. Sometimes it’s momentary, but other times they can last for a couple of days or so in that one localized area. I probably only ever experience them once every few months, but they’re irritating just the same. Are they common? I’ve generally pinched/slapped/smacked them around a bit when they show up, but they typically only stop for a few seconds before resuming. Should I leave them be and just let them have their fun? And assuming they’re symptomatic of muscular or cardiovascular fatigue, what is it that sets them off?