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More efficient running style

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d87heaven Mar 2014 7:17pm, 12 Mar 2014 146 posts	Quote Pin d87heaven At what point does a mid foot become forefoot 51/49% or is it 52/48? Is it full weight bearing or initial contact? What if you land 48/52, is that still mid foot? How do you measure this mid foot and against what standard are you measuring?
GlennR Mar 2014 7:26pm, 12 Mar 2014 9,197 posts	Quote Pin GlennR That would still be mid foot, in fact you'd probably see that much variance from stride to stride on anything but the most pristine surface (and probably still then). Orthodox heel or forefoot strikes would tend very much towards the 0%/100% split.
d87heaven Mar 2014 7:45pm, 12 Mar 2014 147 posts	Quote Pin d87heaven So at what point do you suggest is/isn't a mid foot and how can you reliably define it?
daviec Mar 2014 7:49pm, 12 Mar 2014 3,942 posts	Quote Pin daviec Why?
GlennR Mar 2014 8:03pm, 12 Mar 2014 9,199 posts	Quote Pin GlennR Quite.
d87heaven Mar 2014 8:11pm, 12 Mar 2014 148 posts	Quote Pin d87heaven Why not? Someone is using the term mid foot and I'm asking how that's defined.
Canute Mar 2014 12:07am, 13 Mar 2014 886 posts	Quote Pin Canute Of the various studies of efficiency, few define midfoot very precisely. Many of the studies (eg Ogueta and colleagues; Gruber and colleagues) actually subdivide foot-strike into heel strike (in which first contact is clearly borne by the heel) and non-heel strike (ie mid foot and forefoot are combined). I personally would describe as midfoot any landing where an appreciable amount (say for example 25% or more) of the load is borne on forefoot and on the heel. This is somewhat arbitrary, but I would consider that such a foot strike produces a reasonable compromise between the risks of stress on the metatarsals and also the Achilles associated with forefoot landing, and the risk of the potentially damaging initial spike of ground reaction force associated with heel strike. However there is no convincing evidence that such a foot strike reduces overall risk of injury. Being elderly and prone to inflammatory arthritis, I tend to adjust foot strike according to the effects of recent episodes of arthritis and to pace. However despite having run on my toes as a child, I now avoid a totally forefoot landing.
d87heaven Mar 2014 6:18am, 13 Mar 2014 149 posts	Quote Pin d87heaven First paragraph you mention initial contact. Any idea how they managed to be so accurate as to tell when someone makes ic with both heel and forefoot at exactly the same time? Second paragraph you mention 25% load. Is this at initial contact or some other point in the gait cycle?
Canute Mar 2014 7:58am, 13 Mar 2014 889 posts	Quote Pin Canute You would need to read each of the individual studies to establish precisely what each investigator did, but I think you are being too concerned about details that are unlikely to make much difference. In the case of the studies if efficiency that I have referred to recently (eg Hatala; Ogueta; Gruber), the only distinction was between heel strike and non-heel strike. I understand that the investigators relied on visual inspection alone. Hatala and colleagues provide photos in their manuscript. They did not require any estimate of the proportion of load on the forefoot at foot-strike because there was no visible contact of the forefoot with the ground at foot strike. I appreciate that among Pose coaches there has been discussion about the difference between ‘landing on’ and ‘landing over’ but I am not aware that anyone has quantified this distinction. I believe that this distinction is based on subjective perception rather than measurement. In the report on the Capetown study of Pose (Arendse et al) they provided only a qualitative description of mid foot strike. With regard to my expectations for risk of different type of injury, I am only making an approximate estimate. Nonetheless, I am referring to initial strike. If you wanted a precise quantitative definition of 'initial strike', I could define this as occurring within the first 20% of the time on stance, but that would be spurious precision because I am only making a crude estimate of likely risks. It is pointless to define this too precisely as there are many individual difference that affect risk of injury.
Canute Mar 2014 9:43am, 13 Mar 2014 890 posts	Quote Pin Canute For the sake of clarity, I should have saild: ' no visible contact of the forefoot with the ground at foot strike in cases of heel strike.' I should emphasize that my previous numerical estimates are only meant to be give an approximate description of what I mean by phrases such as 'an appreciable proportion' or ' a substantial proportion' Because of variability between individuals it would be pointless to try to be more precise. It is a matter of judgement. From the point of view of valid science, the crucial issue is whether independent observers would agree with the judgments, in at least the majority of instances. I suspect that few investigators establish the degree of agreement between observers, though strictly they should if there is appreciable ambiguity