Daily Failures, Part 4

The latest blog entries on daily failures focused a bit on reaction times, rhythms and biomechanical aspects. This entry deals with other biomechanical aspects and the kind of information that can be derived from simple conclusions. Again, the idea is to retrieve as much information as possible to successfully “model” an opponent’s intentions. The blog entry “Daily Failures, Part 1” showed the consequences of wrong internal models. The following example shows that some thoughts on mechanics would have helped to avoid the situation.

 

Example for wrong distance

Woman gets attacked by a bear

 

Calling this situation a simple misjudgment is an understatement. The chain is the limiting factor to the bear. It is clearly visible and should indicate the bear’s possibilities. He cannot move any further, but he moves freely within the chain’s perimeter.

The bear’s chain acts as a mechanical limit, but the same principle applies to your own body in combination of force and speed. You can generate a certain force in your actual stance. This force is applied to your “mechanics”, meaning your body. It is pushing you forward or is transferred to your opponent, depending on the situation. It is constantly changing the state of your body. Conversely, the available force is limited due to lever lengths in your body. The current positions of your internal levers limit the generation of force. So, mechanics and force are closely related. One cannot look at one thing and exclude the other thing. All in all, it is like an endless circle. Available force depends on internal lever lengths. Your own generated force is applied to your body. It changes the relation of the levers to each other and accordingly changes the available force [1].

The following pictures demonstrate this interrelationship. But, be aware that it has been simplified. The first and second picture show the upper arm and the biceps. The muscle is coupled to the lower arm. It is pulled when the bicep is contracted . Now, when the lower arm is pulled, the available lever length for the torque, and thus the force, is altered. A shorter lever length diminishes the torque. The third picture shows, again simplified, the relation between the angle and the torque.

 

EN_Winkel_Muskelkraft_3

 

EN_Winkel_Muskelkraft_4

EN_Winkel_Muskelkraft_5

Now back to the bear. Knowing this, you can derive information from your opponent’s body posture. The first aspect deals with the fact that certain stances allow the generation of certain forces. The visible mechanics give a good indication of your opponent’s possibilities. A twisted foot may already give away the information that a stance has difficulties dealing with lateral forces.

The second aspect adds a temporal estimation. You need force to accelerate your own body. So, the available force defines the reachable space within a time frame. The bear’s chain is a pure mechanical limit. But, regarding time, you discover the limitations of your personal scope of movement in terms of time even without such a chain. A bad stance reduces the reachable space within a set time frame. The distance to your opponent may not change, but you lose time due to the reduced force/ acceleration potential. The bear’s stance is perfect. He is sitting on his hind feet and can press his body forward. A stance with a balanced weight on all four feet would have limited his possibilities.

Usually, you don’t have to get into such a detailed level of levers and angles. Testing often suffices for finding practical solutions. These biomechanical aspects come into play when you try to optimize your movements and cannot find a suitable solution using trial and error.

The post was published 27. December 2013 related to the category Miscellaneous and tagged with , .