Because at this point, I've become such an expert on running injuries, having self-diagnosed and treated so many. Well, I've got another one I'm working on, this one a new twist on a classic.
My right IT-band and lateral leg has been going crazy lately. I'll get warmed up about 1-2 miles into a run and start to feel the onset of a tweaking sensation in my lower IT-band - not "painful" as in soreness, but almost a neurological thing. Then, all of a sudden, the tweak intensifies and my leg gives out for a few steps. If you have ever had a sensitive tooth, it's similar to the feeling you get by poking the exposed dentin - you can feel the nerves going crazy, but it isn't really painful at all.
Fast forward from two weeks ago to today, and this crap is still hanging around, even after my arsenal of IT-band exercises. Clearly, what I'm targeting with these exercises is not the source of the problem.
I spent a couple of hours doing all sorts of range-of-motion movements, stretching and contorting my body, and found a very tight, sore, hard muscle just above my knee, on the lateral side. I also noticed a lack of tone in the piriformis muscle on the same side.
The former is the vastus lateralis, of the quadriceps family. Pain in this muscle can develop as an overuse from cycling and running on steep inclines. Yes, I've been stepping up my cycling since moving to FoCo, and I bike to the department, but the hills...back in Seattle, I might get 200ft of gain on a daily run. I get almost ten times that on average without trying too hard. The clincher is that this came on during a long run at Horsetooth Mountain after doing repeats up and down Towers Road - a 3-mile gravel road that rapidly ascends/descends the mountain.
The latter is probably a basic case of piriformis syndrome.
Solutions: targeting the piriformis with strengthening exercises and rolling on a tennis ball. Heat and massage on the vastus, stretching, and range-of-motion for now. I developed a stretch for the vastus utilizing a theraband, picture coming soon.