At times I have called myself both biomechanically perfect and biomechanically average, and I would stand behind both assertions. I can not in good conscious entertain the fact that I am biomechanically below average, because running as much as I have in the past decade would just seem impossible. For a tiny bit of background, here is an interesting article about biomechanics in the running (Jamaican sprinting) community. Sometimes these articles center on the genetic factor that our hips and knees, lower legs, calf diameters, Achilles tendon elasticity, all have certain dimensions that are more beneficial, and being symmetric is in general a help.
I work with a number of people that limp. Wether it is a genetic leg length difference, a hip thing, or some traumatic injury, I do not know. Also, given the three people I am thinking about now I am guessing they are all significantly different reasons. I will say, when I am out pounding out a workout and I think of those people limping it motivates me to push the pace and make it count. It also helps motivate me to do my core and extremity exercises.
My list of injuries is long. I'm not going to take the time to recount all of them, but numerous tendonitis issues, muscle knots and small tears, two bone breaks (due to running), muscle imbalances that led to joint issues, and all of these issues seemed to affect only one side or the other, never both sides at the same time. Therefore, I conclude based on the scant empirical evidence, that I am not symmetrically (and biomechanically) perfect from the neck down, otherwise injuries would happen to me symmetrically. (Definitely not symmetric from the neck up.) Yet, I am closing in on 30,000 miles of running and backpacking over the last 13 years and I am more healthy in terms of muscle balance now than I was when I was 15 and started recording my miles. To have that much consistency under my belt without more than two or three really serious injuries makes me think that I am an outlier in terms of recovery ability and biomechanics.
The truth is, I don't know. I think of myself as very average. Just about any high school sophomore could be where I am physically today, if they had 13 years to work on it, and actually worked on it. Mentally most give up well before they reach where I am, and that's okay, everyone has different priorities and that's great. If we were all the same, I would have to like Bud Light and American Football and spend all of my money on a new car, and none of those things are me. Back on topic, outside of scientific and medical measurements, I don't think there is any way to really know if I am biomechanically average or exceptional. There is so much more to running 10,000 leagues in 13 years than the physical portion of actually running for 4000 hours. The mental side of it is huge! I went vegan last year for 10 weeks! I tweet my bloody socks. I go to bed at 9 PM. I don't know. What I do know, is that the meager physical things I have done are far far more accessible to the vast majority of people than they imagine. Not necessarily today, or tomorrow, or even by next year, but with enough time, nearly anything is possible. We went to the Moon in 1969 with less computer than my iPhone 4S!