For several runs, I've had a lingering dull pain near the upper part of my thigh - borderline groin but it's been hard to pinpoint.
I first experienced this pain during the San Tan Scramble last February...hobbling and humbling, it resulted in my only DNF. Ever.
It has recurred (seemingly randomly) in various situations and distances and despite all my stretching, strengthening and icing I have never been able to figure out what was going on. Until now.
During my run on Saturday, I noticed that as my distance got further and further, my stride changed. Specifically, my right leg got lazy. Instead of pushing my foot straight out in front of me, my lazy leg started to push my foot slightly out to the right. This causes my hips to open up just enough so that my hip flexor and groin have to work a tad harder each stride to propel myself forward and then straighten my hips, knee and foot back in line with each other.
Over several miles, the strain on my hip flexor and groin just caused my right leg to seize up. I really wanted to run some more but it basically said, "No way sucka".
So I conducted a little test for my theory.
My run this morning was focused on keeping good form - throwing my leg straight in front of my knee and limiting the lazy-leg-swagger.
Guess what. No issues. No pain.
I was able to knock out 6 miles with a pretty good pace considering I put 20 in the books the day before.
We'll see if my theory holds up this week.