Hygiene letters section of school hygiene, studying the processes of writing and rationing of this work for children and teenagers as well as adults. In the process of writing in activities involve the brain, eyes, and muscles of the neck, back, fingers middle hand and wrist, forearm and arm. Especially tiring fast P., when some reduction of flexors and extensors of the fingers last about 0,2-0,3 sec. each. At this time the head, bent over the paper maintained in equilibrium continuous tension of muscles of the neck and back sometimes for a long time. The correct position when P. is even more important than reading, as in the process of writing have to make constant motion. When the wrong position of the trunk, with a significant tilt the head forward tense up supporting her neck muscles, resulting in faster, leading to their exhaustion. Consequently, head even more leans forward or leaning to one side, while engaged in work nearby muscle groups. Prolonged P. children and teenagers in search of support for head rely breast on the edge of the table; this is squeezing in the chest, violation of normal blood circulation and breathing. Adult persons with normal vision should keep a notebook or paper on the length of 30-35 cm; for children and adolescents, the distance increases to 35-40 see the Minimum allowable distance notebook from the eyes of the 30 see
The process P. associated with the work of muscles, resulting in the movement of the eyeball. His movements on the line going at an oblique angle to the transversal axis of the eye, causing fatigue eye muscles, especially when the notebook is on the table correctly and at the wrong landing writing.
The main line of the eyes should be parallel to the edge of the table and the transverse axis of the body. In this situation the eyes of the writing process causes the least fatigue subject to mandatory compliance with hygiene requirements for process P.
The normal process P. requires the participation of only three fingers. The handle should be held between the thumb and index finger, without strain. Other fingers should be slightly bent, one under another. At this writing usually sees the Palmar surface. The handle must be at an angle of 60 degrees.
Among teachers and hygienists have long been a major dispute is the question of oblique and direct mail. Direct email is hygienically has some advantages, because it gives the opportunity to more easily ensure the correct fit of the student in school than at an oblique P. In direct P. the book is on the table right in front of the body, noting should be positioned directly in front of the notebook, length lines should not be too great, from the top to the bottom line of notebook move up.
In the schools of the USSR took the letter with a slight incline (10-15 degrees), which gives the opportunity to use advantages of both direct and oblique P.
In the early grades of written work better to arrange more often, but make them shorter.