I recently read an article that was lambasting the concept of natural motion. The author first provided the idea, that numerous martial arts instructor's convey the suggestion, that what they are teaching are "natural" motions. He then proceeded to explain (his version of) what “they” meant by that statement “By natural, they mean that the motion be closest to the motion the human body is adapted for” (Which was the definition that I disagreed with).
Who” (exactly) wrote that definition of/for natural? Though possibly written poorly (as I would never define motion in that manner), I don't believe that their intention (or definition) was the one that this author chose for them to have represent their viewpoint.
The author believes (he's the one that stated it) that any/all motion is “created”, for the required task at hand. He then went off on a tangent regarding “evolution” (and what that equates to). Not having a link to the original documentation/article (source, that the author was referencing) it would be difficult to know the implications of any statements were made within it.
His followup statement “There is no such thing as natural movement for the human body. Those who think there is do not understand how natural selection works.” was (IMO) at "best" showed the writer to be ignorant (of the subject), and at "worst", was misleading and unrelated (to the topic of the subject). “Natural Selection*” is a separate issue/subject from “Natural Motion”. The two are only distantly related or in any way similar.
Interestingly (at least to myself, LOL), I had only recently included the footnote at the bottom of my blog. It was actually in reference to articles exactly like the one I'm referencing in this blog.
The term “natural”, has numerous avenues of definition. The one that I found most applicable (for the purposes of training) was the “any person or thing that is, or is likely, or certain to be very suitable to/for as well as being successful in an endeavor without much training or difficulty”(via “Dictionary.com”). As “I” interpret this definition, it means the motion that is most likely to occur without having any (or much) formal training to perform.
Regardless of how or why it does so, the human body (as well as the average person's limbs that are attached to it) will move in (only) particular, often limited ways. To imply (as the author did in his article) that any motion that you are able to perform is “natural”, is simplistic and (IMO) just stupid.
If every motion were indeed “natural”, there would be no need for training. The body does perform certain actions and motions that are familiar, and therefor require little (if any) conscious thought to perform them. In the quest for efficiency though, it becomes our goal (as instructor's) to make a student's naturally performed motions be as productive as possible.
It is in that regard, that we have our students repeatedly perform numerous introductory motions (with the intend of making the student more comfortable/familiar with that motion, and thereby requiring little to no conscious thought to performing them) as/when required.
In regards to natural motion, unlike what the referenced author stated, we do understand what that constitutes, and we impart that knowledge upon our students as well.
*Natural selection is the gradual natural process by which biological traits become either more or less common in a population as a function of the effect of inherited traits on the differential reproductive success of organisms interacting with their environment. It is a key mechanism of evolution. The term "natural selection" was popularized by Charles Darwin who intended it to be compared with artificial selection, which is now called selective breeding.