Step width, "head over foot"?
There has been some decent debate on "head over foot" running biomechanics. We postulate from our years of reading research and studying people's gait (coupled with physical examination, a neuromuscular assessment, not just a visual assumption) that the head should remain within the limits of the step width. This theory falls apart if someone is a crossover gait runner or walker (search our blog for this "cross over gait" idea). IF one is a narrow step width (cross over gait, not a literal cross over of course) then the head must basically be over the foot on each step. But this is a gait with severe limitations and lots of risks and biomechanical problems as we have written about many times, though one can say is has some economical aspects which we have proposed many times.
But, if the head is outside the step width, one is leaning and this resembles a pathologic Trendelenburg gait. Can we definitively then say that when the head is outside the foot contact (beyond the limits of a person's step width) that it is problematic? No, but it is likely pathologic and clearly uneconomical.
So the fence seems to be the head over the foot.
If you are outside that fence even a little, you may be (we strongly believe) on the wrong side of the fence. Look at a CP gait (photo below) for example, point made. So, would you rather be on the other side of the fence? We would, we want to be inside the step width and we are fine going right up against the fence (the head foot) but not over top of it. One cannot just say that the head over the foot is better. What about hip and pelvis stability ? If the hips-pelvis are drifting into the frontal plane, this will put the head over the foot as a default. So does this validate the head over foot theory as good in this client ? No, we see this as a problematic gait all the time, lots of hip and spinal stability issues in these clients. One cannot stand and preach on head over foot alone. We just made the case that in a frontal plane drift pelvis client, this is a compensatory default, but it doesn't make it a good thing, far from it.
For now, we will stay put that, with all other faulty mechanics not present, a more sound head position is to be found between the limits of the step width. Yes, right up to the fence of "head over the foot", but not over top as a sound pattern to play with. Why risk falling over the fence on some steps, Try this, stand on one foot, put your head over the foot. In this position, you had to drift the pelvis laterally into the frontal plane. Now try to effectively engage your glute. Enough said, for now. So why would we promote this as an effective running form? More to come we are certain, but we are open to debate, and to being schooled wrong. If you wish, go into our blog (link below) and read up on the effects of step width on gait, and all of the risks/problems that a narrow step width promotes (ie. head over foot).