The height of desks and chairs is crucial to students' health and learning outcomes.

Properly adjusted desks and chairs help students maintain a good sitting posture, reduce fatigue, and avoid physical discomfort and health problems.

Determining the appropriate height difference between desks and chairs requires comprehensive consideration of multiple aspects such as ergonomics, students' height, grade, and learning environment.

First of all, from an ergonomic point of view, the height of desks and chairs should support students' natural sitting posture and avoid excessive tension in the spine and muscles.

When students sit on a chair, their feet should rest flat on the ground, their knees bent at a 90-degree angle, their hands naturally placed on the table, and their elbows bent close to 90 degrees. This sitting posture helps maintain the natural curve of the spine and reduces pressure on the back and neck.

Secondly, the height of desks and chairs should be adjusted according to the height of the students. The height of students of different ages varies greatly, so the height of desks and chairs should also be different.

Generally speaking, the height of the desk for primary school students is between 60-70 cm, and the height of the chair is between 35-40 cm; for middle school students, the desk height is between 70-80 cm, and the chair height is between 40-45 cm; for high school and college students, the desk height is between 75-85 cm, and the chair height is between 45-50 cm.

This is only a rough range, and the specific height needs to be adjusted according to the actual height of each student.

In addition, the height difference of desks and chairs also needs to take into account the grade and learning environment of the students. The learning tasks of lower-grade students are relatively light, and they are more engaged in writing and painting activities on the desktop.

Therefore, the height of the desktop should not be too high, and the height of the chair should also be moderate so that they can use the desktop easily.

Senior students have heavier learning tasks and need to do more reading and writing activities on the desktop, so the height of the desktop should be appropriately increased to maintain a good visual distance and avoid visual fatigue.

In practical application, how can the height difference between desks and chairs be determined? Generally speaking, it can be adjusted through the following steps. First, measure the height of the students, and then determine the initial height of the desk and chair according to the height.

Next, let the students sit on the chair with their feet flat on the ground and their knees bent at a 90-degree angle. At this time, the height of the chair is appropriate. Then, let the students put their hands on the table and bend their elbows at a 90-degree angle.

At this time, the height of the table is appropriate. If the students feel uncomfortable, fine adjustments can be made according to the actual situation until the most suitable height is found.

It should be noted that the height difference between desks and chairs is not just a simple subtraction of the height of the table and chair, but the overall sitting posture and comfort of the students should be taken into account.

For example, some students are shorter but have longer legs. In such cases, the height of the chair may need to be slightly higher so that their feet can be placed flat on the ground, and the height of the table needs to be adjusted accordingly to maintain the natural bend of the elbows.

Therefore, when purchasing desks and chairs, products with adjustable heights should be chosen so they can be adjusted according to the actual situation of the students.

Schools and parents should also regularly check the height of students' desks and chairs and make timely adjustments to ensure that students can maintain a good sitting posture and healthy state during the learning process.