Hi,
Can anyone please verify the claim that there are 700,000 unique body movements? Please see this link. There are others like it. Thanks.
davidmich
What exactly are you calling a “body movement”? That statistic is repeated all over the place without it being clearly defined (or at least nothing obvious popped up during my admittedly brief google search). But, let’s say for example you just count the following joints, and consider each one to only be in one of two positions: neck (up/down), head (left/right), shoulders, elbows, wrists, fingers and thumbs (10), hip, waist (rotate torso left or right), knee, and ankle (we’ll assume you are wearing shoes so any toe movements wouldn’t be obvious) that’s a total of 24 joints, if I counted correctly. That gives you 16,777,216 possible combinations (2 to the 24th power), well in excess of the 700,000 number.
All of those joints have more than two positions, so the actual number of “movements” you could make would be significantly larger than that.
I’d pay much to watch someone perform movement number 16,777,216, in which he reverses the position of every single one of those twenty-four joints!
Thanks engineercompgeek. That’s a helpful analysis.
davidmich
The definition implied by engineer_comp_geek seems seriously over-contrived, which I’m sure is exactly what Trinopus is thinking too. He seems to consider a relatively small number of “elementary” or “primitive” movements, then counts every combination of such elementary movements as a distinct movement in the sense that OP wants to count.
My first thought, which I still think is the more interesting question, is how many unique “elementary” movements are there?
It’s still necessary to define that. How about this: For every muscle in the body, the flexion of which produces a visible body movement, an “elementary” movement is defined. This definition would include movements of bones and joints (e.g., arms, legs, head and neck movements, etc.) but also movements involving soft tissue only (e.g., many facial expressions).
Now, how many of THOSE are there?
Many articles refer to the following: head, face,eyes, nose, lips and mouth, arms, hands, legs and feet and the actions performed with them.
Understanding Body Language from Head to Toes.
http://www.nacada.ksu.edu/Resources/Clearinghouse/View-Articles/body-speaks.aspx
http://www.ukessays.com/essays/nursing/understanding-forms-of-communication-in-clinical-practice-situation-nursing-essay.php
Source of the figure 700,000:
Argyle, M., The Psychology on Interpersonal Behavior. (London: Penguin 1978)
davidmich
Not anything like 700,000 . You are trying to write a indistinct definition that someone may then think 'oh so that matches 700,000 . Thats REALLY a contrived definition!
There are approximately 642 skeletal muscles within the typical human, and almost every muscle constitutes one part of a pair of identical bilateral muscles, found on both sides, resulting in approximately 320 pairs of muscles, as presented in this article. Nevertheless, the exact number is difficult to define because different sources group muscles differently, e.g. regarding what is defined as different parts of a single muscle or as several muscles. Examples range from 640 to 850.
of course, many work in unison only to hold the body or make the movement smooth, so there are far less unique movements than muscles.
Now if you want to talk about the result of multiple movements having different looks… Then why not count facial expressions ? Why not count finger “expressions” ? If you said each finger can have 10 positions , then the number of finger expressions is 10^10.
The linked source of the number 700,000 says “forms of body language” not “movements” which makes a lot more sense.
Some of those configurations won’t be possible - for example, the individual joints of each finger are not really independently controllable, as the muscles that control them are in the forearm, connected by tendons, but not one per joint.