Consequences of early pole drop

[Robert schmitt]

I had to get my 25 CE credits for my chiropractic license and I found this course that also meet my WIAA coaching CE req. If you read through the entire course work I'll tell you there are some flaws and I hat his definition of lever systems in the body. what he is saying is true but he should not be trying to re-define lever classifications...anyway the point is..
They mathematically show through vector analysis that moving the center of mass of the torso in front of the hip will cause the hamstrings to have to compensate for this.... causing a 1)shortened stridlength 2) a less efficient movement because now the hamstrings are working to maintain incorrect posture and locomotion and 3) Increased likely hood of injury to the hamstring because it is firing to maintain incorrect posture when it should not be active. While the explanation was based solely on running with a slight forward lean I realized that this same phenomena will happen is a pole vaulter has to exert any effort to carry or counter balance in pole drop that is not free. In the text example in a 200lb man if the upper body COM is 4" in front of the hip the hamstring muscle has to produce 843 lbs of additional force to stabilize the trunk that a person with the COM directly over the hip does not have to develop.

Here is a link to the material and skip to page 112 for the discussion and vector analysis.
http://www.spinalfitness.com/Manual%201/manual%20%201%20part%202.pdf

[KirkB]

A very good point ... and the reason why you want to drop the pole as "weightlessly" as humanly possible.

I hadn't seen those numbers before ... it's good to see quantitatively the forces at work during the pole carry and pole drop. These numbers are NOT negligible!

Kirk