I'm a runner and think I have strained something in my right hip flexor. Though I didn't think it was severe I've noticed some weakness in the area over the couple few weeks and when I've stretched out my hamstrings I've been feeling an unusual twinge on my right side. Then a few days ago I realized that I have numbness on the right side of my body - the entire leg, butt, and up the back a bit. It's not painful but as if sensation is not quite sharp, like when you're warming up from the cold. What could this be? As a side note, I've had moderate lower back problems for years that I've kept manageable with stretching and pilates.
