Re: Help My Back!
It sounds like your own stretch reflex caught you and painfully recontracted your muscle. If you push yourself quickly in a certain direction, like reaching for a newspaper, which is fairly common, your muscles protect you with a reflexive pullback, if say those muscles are already contracting at some previous rate. Of course afterwards you get what you may be experiencing right now. When I play football and reach for the ball too many times, my calf may go into a similar circumstance, gets very tight and any movement further may cause it to spasm if not careful.
Like untying a knot, if you pull on it, it'll tighten, but if you were able to move gently towards the direction you moved and then slowly release it, rest for a moment, then gently try it again, you may find the area beginning to soften as a knot will if moved