Limb Dominance discussion

Page 3

Del

John Fisher wrote:
>Picture if you will a cone. The short diameter end represents a shorter stride, or distance traveled. (Circumference) The opposite for the longer side. What happens when you roll the cone? 

Ok ... if you put smaller size tires on one side of your Bronco and you tried to drive straight this would be true. We do not use wheels, cylinders, nor cones to walk... we walk more like two parallel swinging pendulums. The gait Analysts show us that. Walking is propelled by the push off of your toe which allows you other leg to swing forward to the next heel contact ... the swing can happen with very little energy usage ... but during this swing the spine, hip, knee, ankle, and foot have a million different possible directions/angles to tweak the placement of your next foot. The turn (without stopping) of the 'blind' human walk is VERY complex and can not be shortened to a one line explanation ... like different step length.

Del

>>Do they really circle if there is an absence of striking terrain or distant landmarks to gauge with?

Let me add that some go left, some go right, some go straight, some wiggle back and forth.

Thorn

>The statisticians have NOT offered any data on circling left or right.

perhaps they were not looking fer this. it may have not been a  consideration at all. ya have to measure something before ya have  statistics on it and the absence of the statistics on a thing does NOT  mean an absence of the thing itself.

anyway, dominance refers to an INDIVIDUAL and statistics apply to GROUPS. therefore there would be no statistics on a person's dominance.  however you could compile a statistic on how much of the pop. is left dom, how much right, how much is ambi, etc.

but since statistics only apply to groups, it is useless to apply them when tracking a human cuz you won't know if he/she is right or left dom  based on the stat, and playing the odds could turn out fatal. ya need to, therefore, look at the tracks and know so the INDIVIDUAL can be  found.

you could say there is a 20% chance i am left handed for example (or whatever the statistical average is). i'd say yer wrong. you'd say, no,  i've read the stats and 20% o' the pop. is left handed so there's 20% chance yer lefthanded so i'm gonna figger that into my search effort, or  whatever, detective work. well i say yer gonna make some pretty bad decisions cuz there's 100% chance i'm lefthanded. either ya are er ya  aren't. and that's where being able to track an individual critter and read it's tracks is superior to statistics. that's where knowing any  fact about anything or anyone beats statistics.

Tom Manning

Are you saying we really walk like this?

Left |----| |----| |----|
Right |-----| |-----| |-----|            Note: I am not sure how Tom’s step diagrams lined up  ...  this is how my program gave them to me. Del

'Cause last time I looked, I walk like this:

Left 1----2----3----4
Right 1----2----3----4 Note: I am not sure how Tom’s step diagrams lined up  ...  this is how my program gave them to me. Del
where the numbers represent footsteps (i.e. footprints)

Notice that if my left step is longer, I can walk in a straight line, but eventually my right foot ends up way behind.
Left 1------2------3------4------5------6------7------8------9
Right 1----2----3----4----5----6----7----8----9 Note: I am not sure how Tom’s step diagrams lined up  ...  this is how my program gave them to me. Del

I've tried your suggestion with popsicle sticks and walking a grid, and the only way I can make it come out is if my left stride is half my right is to
take two steps with my left for every one on my right. In other words, my left foot doesn't take off from the tip of my right foot, it takes off from
where it was last time I set it down. Do the popsicle sticks represent the foot, or the length of the stride? Your illustration doesn't convince me
that disparate stride lengths cannot be the cause of deviation from a straight line of travel, but maybe I'm confused.

Just trying to clarify one aspect of this whole discussion...

Del

>anyway, dominance refers to an INDIVIDUAL and statistics apply to GROUPS. therefore there would be no statistics on a person's dominance.  however you could compile a statistic on how much of the pop. is left dom, how much right, how much is ambi, etc.

This would be good ... but other than direction of blindfolded travel and difference of step length, how would one do this?

As I see it though, you have only three groups here ... left travelers ... right travelers ... and straight travelers There is a problem of not being able to do a debriefing
interview with a dead body to rule out all of the terrain navigational details.

>what do you mean doing poorly or doing well? what was the study looking for? how many people were involved? before this study can be applied to the subject of dominance too many questions need to be answered. It maight be completely irrelevant to the issue or it might be quite pertinent. but just because people were walking blindfolded doesn't mean the study was about dominance. i could blindfold people and see if they could find a cherry pie with their noses and draw conclusions about smell or blindfold them and send them across a course to see if they can feel what kind of surface their walking on and make conclusions about hearing and foot sensitivity, but in neither case will I be able to authoritatively draw conclusions about dominance unless I look fer it specifically and design the experiment as such.

As stated this was read years ago and that they were trying to answer the question of lost soldiers ... Knowing the soldier and what his back ground was (farmer, city dweller, Native American ... etc. )which way would they go when lost ... particularly in a dessert or an arctic environment. They wanted to solve the dilemma of where to look for there guys ... sampling was in the many hundreds. I recall that it was flat, windless, and cloudy.

Del

I believe that we are confusing step length with pace length and stride length.
 
>I've tried your suggestion with popsicle sticks and walking a grid, and the only way I can make it come out is if my left stride is half my right is to take two steps with my left for every one on my right. In other words, my left foot doesn't take off from the tip of my right foot, it takes off from where it was last time I set it down. Do the popsicle sticks represent the foot, or the length of the stride?

The popsicle sticks represent the length of a STEP, two sticks equal a STRIDE, the foot is not represented. The step of one foot ends at the beginning of the next heel strike.

Del

I believe that the miscommunication begins when pace/stride and step are used interchangeably. I am understanding that limb dominance as described by TB and his students is determined by a difference in STEP length ... Pace length is a limb swing and  is either left or right ...  it is the combined travel of two steps.

Barry Brodeur

>See you can walk a straight line with two different lengths of steps and you can walk a turn with two different lengths >of steps ... without tripping. 

I don't see it your way because that short stick had to move more than the long stick to keep up. If each side takes only their independent strides the short one is losing ground. Man this is hard to do on the net! And I did try to do exactly what you wrote. But did you? and did you notice the space that the short stick left when moved each time to the front of the longer stick? That is space or travel unaccounted for. I really am not trying to argue, just trying to see your ideas or thoughts.

Del

>I believe that the miscommunication begins when pace and step are used interchangeably.
>I am understanding that limb dominance as described by TB and his students is determined by a difference in STEP
>length ... Pace length is neither left or right it is the combined travel of two steps. 

Del

Pace is not as I have defined it .... pace is the measurement of two steps. A pace is not on one side or the other. There is NOT a  right pace and a left pace.
A pace can be a left step and a right step or a right step and then a left step. A step begins with a heel strike and then ends when the opposite heel strikes.

Del

>Sure, the distance L1 to R1 can be different than the distance R1 to L2 and I can walk a straight line. But that is not what is  purported to create a tendency to walk in an arc. What if the distance L1 to L2 is greater than R1 to R2 ("overall stride" or the distance from heel to heel or toe to toe of the *same* foot)?

This is where the sticks may help you visualize it. View the sticks as step length. A two step in succession (a left and then a right OR a right and then a left) is a PACE. Even if the pace distance changes there will be no turn unless you pivot a stick to achieve a turn. The turn is not determined by a step length nor the pace length.

Yes Barry to answer your question ... I have tried it, am still doing it on my desk as I type.

Definitions:
A step begins and ends with a heel strike. Measured from heel strike of a foot to the heel strike of the opposite foot. A pace is a series of two steps. A Left and a Right OR a Right and a Left.

Mix your sticks around ... using them again as STEP LENGTHS. I can place two short ones in succession (a short first pace), then a short and a long (for the next pace), two long steps (for the third pace), two long steps (for the forth pace) and so on... I continue to get a straight line if I choose .... I can also curve it in either direction ... Turns are relational to a pivot that takes place at the beginning of the Step (at least that is as it appears to me).

So I guess my question at this point is: Is a dominant limb really the cause of a slight turn? Or is the slight turn being generated by ????

Thorny

it seems to me del the same comment can be made about these sticks (and  after keeping a dish of sand at my desk for months my cohorts didn't  even hafta ask about the sticks) that can be made about the cone. we  don't walk on cones and we don't walk by sliding sticks long either.

the turn could be induced by the greater inertia of the swing more so than stride length, but both are contributing factors.

Del

Appears that the foot pivot forces a contraction or extension of the leg swing and therefore a longer measured stride.

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