This is a real puzzler for me! On Tue morning I finished the last of 4 nightshifts and set off to cycle home. Nothing unusual there, but within 100 yards of leaving the factory gates I knew something wasn't right. I felt as though I had pulled something in my right leg, maybe a muscle from my groin down my inner thigh . If I pushed hard (as I normally do) it was agony, so I had to back off and balance pace against discomfort. It didn't loosen up for the entire ride of 10+ miles and the other leg also began to feel the same shortly after. It is now Friday and things still ain't right. Bending down to pick something up, crouching, or even sitting/standing from the loo hurts! I feel almost as weak as when I broke my kneecap a couple of years ago. I would say I feel like I have been doing an unusual activity, like shoveling rubble while leaning in through a hole in the floor, but I haven't. I did a spin class with Mrs Skol on Fri before starting work. Not something I do very often but not the first time either. No pain afterwards and I then cycled to work for 4 nights absolutely fine until coming home on the last trip. I did get back out on a bike yesterday with a visit to an MTB trail centre but my legs definitely are still not right and I had to be careful, get it wrong and I was rewarded with sudden twinges and stabs of pain The rest of my body is normal, just seems to be muscular and hip/thigh related, so I guess that rules out any flu type virusy things making my skeleton ache? I have wracked my brain trying to remember any unusual activities I may have done on that last night at work or the day before (sleeping). What on earth could be wrong with me?