What did I hurt: quad, adductor, hamstring- (all 3,other)?

TFL

I don't think so. TFL is like the top of the ITB, outside.

This is inside and gluteus, back, hamstring.

possibly your psoas

It sounds like you could have several strained muscles.

But because you mention the back pain, it is also possible that you have pinched/damaged a nerve(s), perhaps the sciatic nerve supplying the hamstrings. This might have caused the back pain initially; when you took some ibuprofen, the back pain went away, but the motor unit (connecting the nerve to the muscles) could still not be 100%. Thus, the weakness.

Just throwing some ideas out there...

Sounds like a classic case of a Schmitzenfetter strain.

I agree with this. You might have some sort of injury to your psoas/iliacus (most likely just tightness, as it's damn near impossible to tear it), which is often characterized by back pain (pulling on it's origin the lumbar vertebrae). It can cause TFL/ITB pain as well, since a tight iliopsoas could cause a slight leg adduction, stretching the TFL/ITB more than usual and causing the greater trochanter to rub up against the TFL more tightly. The pain in the groin - is it more on your pelvis or your femur? If it's up at the very top of the femur I'm definitely going with the iliapsoas, since it's insertion is on the femur. Pain in the buttocks... not sure.

Pinched sciatic nerve would cause numbness or tingling in the thigh, wouldn't cause back pain. This still could be the case though if he's hurt his iliopsoas, since the possible adduction mentioned earlier could be pulling on the piriformis which also inserts at the greater trochanter. Sciatic nerve travels through the piriformis, maybe gets pinched a little with the extra strain on the piriformis, and your scenario with the motor unit and thigh weakness could be correct. This could also explain the buttocks pain, as the piriformis is deep to the gluteus maximus.

So if I had to guess, I'd say a tight iliopsoas that's adding extra stress to some of the muscles that attach (or pass over in the case of the TFL) to the greater trochanter (TFL, piriformis, gluteus minimus, inferior/superior gemellus, internal/external obturator).

An educated guess, but by no means a professional diagnosis. Go get checked out.

You guys are good.

http://www.somatics.com/psoas.htm

And LOL yeah I'd say tearing this thing would mean you have some other more serious issues. Interesting that Pilates apparently has a lot to do with these "core" muscles.

I'll just take it easy the next few weeks, no speed.

This is very similar to what I have, pain and spasms in the lower back and at the top of the thigh/pelvis area (deep inside)and because I kept running on it for a week my groin is extremely sore aswell. Did you get it sorted?

My recommendation whould be to go to a good massage therapist and if its not getting better after a couple of visits, I would get some Active Release. Once you're on the path to recovery, you should start a stretching regiment and some strengthening (core, hamstrings, adductors, abductors, quads).

Just don't ignore it. This type of thing can become chronic and last months or years. I've learned from experience.