Arm goes up only




Lean one arm against the wall and try uploading it with all your strength.
After a couple minutes of effort, handouts and you will see how the arm 'relaxed' stubbornly up without anyone tells you.
This effect is known as the illusion of Kohnstamm and depends on the motor memory.
The arm strength continues, because the brain and muscle were used to it and take a few seconds to remove the 'automatic pilot' and adapt to the new situation.





The arm is shortened




Stand perpendicular to a wall, so that, with the arm extended, touch the tip of the fingers.
Then raise your arm, rotating it over the head.
Now extend it again and you'll no longer reach the wall.
Quiet, not that you are shrinking by the minute. Codema is the paradox, which is based on the fact that, by a certain movement in the joints of the back, your muscles contract slightly.
Simply 'drop' the arm muscle to recover the original size, demonstrating that the muscles can only contract, and to resume its relaxed state need the help of other 'colleagues' that stretch, they come at the expense of themselves in action.
Muscles only contract
The human body has about 640 skeletal muscles, some of them, capable of great precision movements. But have a little 'little defect': only know contract, ie, they can only pull, not push. And this 'detail' forced to appear in many cases inseparable pairs, running antagonistic movements. Nor can con-brought much, just a few inches, but longer movements achieved through the multiplier effect that makes bones and joints.





Fingers which are relaxed




He folded his hands as in photography and strong in your index fingers are straight and parallel.
Now relax them and see what happens with them. The muscles and tendons, when not active, adopt a minimum energy.
In the case of the hand, fingers slightly curved tend to be arranged.
This experiment also serves to check the qualities of the muscles and tendons of the hand, are perfect for precision work, but lack of resistance.
How you can keep the index fingers completely straight before crying out for a little rest?





Silly finger



Place the hand on the table as shown in the image and try to move individually each of the fingers while holding the others supported.
If you are not a 'freak', you may have been a disappointment to 'fritters' with your finger.
Although each finger has its own tendons that attach the muscle in the back of the hand there is a connection 'additional' between the tendons of the ring finger and limiting the mobility of both fingers separately.




Reaction time



One way to measure what is your reaction time is drawing to a rule and the help of another person.
This rule should hold at its upper end, while you place your fingers around the other end, ready to catch it at the time that your partner's release.
The height that captures the rule will let you know how many inches you need to react.
Now, no cheating, just compare your results with the table below, to assess how good is your ability to react.

Do you react in time?

Distance Reaction time
9 cm 135 milliseconds Excellent
11 cm 150 milliseconds Very Good
14 cm 170 milliseconds Well
16 cm 180 milliseconds Pretty good
20 cm Regular 200 milliseconds
24 cm below 220 milliseconds average
30 cm 250 milliseconds Poor





The sock




Are you wearing socks made​​? Well do not look and try to touch the edge of one of them with the fingertips Have you just right or you have approximately?
The phenomenon that explains your lack of sight is known as 'habituation', or the ability to sense
two to adapt to the presence of a continuous and constant encouragement, and not paying attention.
Habituation also affects the taste and smell. Nose receptors quickly get used to the smell and stop just a minute to appreciate it later, which poses a danger if a gas leak.





View




While the brain uses visual information it receives from both eyes, one of which provides more details of the final image is perceived. It is the dominant eye.
To find out just point out an arm and a distant object.
Without moving the arm, close the right eye and see the object.
If this does not deviate, the left eye is dominant, if displaced, is right.





The pulse




The pulse, as well as felt through the touch, can also be seen. Literally.
To do this, simply locate the point of the wrist where it is most intense and holding a straw with clay.
With each beat of our hearts, the straw will oscillate very slightly.
The radial artery passes just under the skin and bones of the wrist, so that they form a good basis on which artery pressure and feel the pulse