Comments on: Where should the foot land? http://canute1.wordpress.com/2008/01/02/where-should-the-foot-land/ Tue, 22 Dec 2009 07:53:23 +0000 http://wordpress.com/ hourly 1 By: canute1 http://canute1.wordpress.com/2008/01/02/where-should-the-foot-land/#comment-50 canute1 Sun, 13 Jan 2008 11:54:02 +0000 http://canute1.wordpress.com/2008/01/02/where-should-the-foot-land/#comment-50 Bill, I agree regarding Jack Becker's formidable intuitive feel for Pose, and I believe he is absolutely correct to suggest that we should land a little in front of the COG. I will post a full explanation for my belief in my blog later today. Canute Bill, I agree regarding Jack Becker’s formidable intuitive feel for Pose, and I believe he is absolutely correct to suggest that we should land a little in front of the COG. I will post a full explanation for my belief in my blog later today.
Canute

]]> By: Bill McGuire http://canute1.wordpress.com/2008/01/02/where-should-the-foot-land/#comment-40 Bill McGuire Fri, 11 Jan 2008 02:28:48 +0000 http://canute1.wordpress.com/2008/01/02/where-should-the-foot-land/#comment-40 Canute, Jack Becker, who is the main guiding voice on the Pose forum, has suggested a few times that landing a little in front of the COG is acceptable. I can't say for sure, but I suspect his reasons are based on his formidable intuitive feel for Pose more than on mathematics. But still... Canute, Jack Becker, who is the main guiding voice on the Pose forum, has suggested a few times that landing a little in front of the COG is acceptable. I can’t say for sure, but I suspect his reasons are based on his formidable intuitive feel for Pose more than on mathematics. But still…

]]> By: canute1 http://canute1.wordpress.com/2008/01/02/where-should-the-foot-land/#comment-17 canute1 Fri, 04 Jan 2008 20:30:02 +0000 http://canute1.wordpress.com/2008/01/02/where-should-the-foot-land/#comment-17 Jeremy, I agree that landing in front of the COG presents a problem due to the braking effect which might waste energy and increase the risk of injury. Therefore, I did not start from the assumption that landing with foot in front of the COG is good, but I was forced to consider the possibility that it might be necessary to prevent a face-down fall. Unless the length of time on support is zero, then the body will move over the point of support during the stance phase, and so we must spend some time off balance. As described in my blog on where the foot should land, when the COG is in front of the point of support, gravity exerts of force that creates a torque that rotates the body (head forwards and down). Dr Romanov argues this torque is useful. However, it raises a problem. Unless the torque is reversed at some stage in the gait cycle, a face down crash will occur. That is why I raised the possibility that landing in front of the COG might be necessary, because it would create torque in the opposite direction. There might be other possible ways of applying reverse torque, such as active flick of the foot at lift-off which could produce the required reversed torque. I will attempt to calculate which is the most efficient way to apply the reverse torque in the near future. Jeremy,
I agree that landing in front of the COG presents a problem due to the braking effect which might waste energy and increase the risk of injury. Therefore, I did not start from the assumption that landing with foot in front of the COG is good, but I was forced to consider the possibility that it might be necessary to prevent a face-down fall. Unless the length of time on support is zero, then the body will move over the point of support during the stance phase, and so we must spend some time off balance. As described in my blog on where the foot should land, when the COG is in front of the point of support, gravity exerts of force that creates a torque that rotates the body (head forwards and down). Dr Romanov argues this torque is useful. However, it raises a problem. Unless the torque is reversed at some stage in the gait cycle, a face down crash will occur. That is why I raised the possibility that landing in front of the COG might be necessary, because it would create torque in the opposite direction. There might be other possible ways of applying reverse torque, such as active flick of the foot at lift-off which could produce the required reversed torque. I will attempt to calculate which is the most efficient way to apply the reverse torque in the near future.

]]> By: Jhuffman http://canute1.wordpress.com/2008/01/02/where-should-the-foot-land/#comment-16 Jhuffman Fri, 04 Jan 2008 13:53:26 +0000 http://canute1.wordpress.com/2008/01/02/where-should-the-foot-land/#comment-16 Canute, Intuitively the support of any structure is best supported by having the CM being directly over the point of support. So, why would you assume that landing in front of the COG/GCM is good or bad just because an elite runner does this to some extent. To me it makes more sense that anyone who lands ahead of the COG/GCM that it will create a less than ideal position for support of the body. And since we know that our body must move to this point regardless of technique we choose to emulate, I don't understand why you postulate such and arguement to begin with...... Canute,

Intuitively the support of any structure is best supported by having the CM being directly over the point of support. So, why would you assume that landing in front of the COG/GCM is good or bad just because an elite runner does this to some extent. To me it makes more sense that anyone who lands ahead of the COG/GCM that it will create a less than ideal position for support of the body. And since we know that our body must move to this point regardless of technique we choose to emulate, I don’t understand why you postulate such and arguement to begin with……

]]> By: Jhuffman http://canute1.wordpress.com/2008/01/02/where-should-the-foot-land/#comment-12 Jhuffman Thu, 03 Jan 2008 03:56:14 +0000 http://canute1.wordpress.com/2008/01/02/where-should-the-foot-land/#comment-12 Canute, I am curious as to why you only seem to want to emulate Haile's running form. Why not emulate one of the many other elite distance runners? Canute,

I am curious as to why you only seem to want to emulate Haile’s running form. Why not emulate one of the many other elite distance runners?

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