Oh yes, working out more than you should or lifting heavier than used to could cause spasms, pain etc. AGAIN with this ^$%&$ snow I went out at 4:30am to get the 2 inches of heavy slush off the steps and walkway before it turned to ice, after being at my parents last night shoveling THEM out (they are away) now I hurt my LEFT tricep so bad I can't put ANY pressure on my hand on that side because it feels like it is driving a knife through the muscle! (Although I have the ENERGY of a 20 year old, my muscles at 55 just don't like the "workouts"), but overdoing things can cause ANY symptoms like pain, stabbing, throbbing, twitching, etc at ANY age. A nerve compression in the lower back will cause the leg issues - so will overdoing leg exercises, the leg muscles themselves. (as we speak my butt muscle started twitching!) Snow snow, go away!