Rule Of Foot Type

In the last section, the length coefficient, circumference coefficient, height coefficient and so on, all belong to the rule of foot type.

The value of the foot type rule is obtained through a large number of foot type measurement data and scientific mathematical statistics.

The data measured by each person only represent the characteristics of this person's foot type but not related to the foot type characteristics of others.

Only after sorting out a large amount of data is it possible to become a regular value.

Sometimes a similar value can not be found, but the measured value should fluctuate on the regular value.

If the numerical deviation is too large, the foot type is special.

It can not be treated routinely in the last design and sample design.

Large scale foot measurements were carried out on one hundred thousand consumers in China.

The change of foot pattern was influenced by age, sex, area and occupation.

For children at 1-4, the annual increment of foot length is greater than about 10mm, while the annual growth of the plantar girth is about 9mm.

After the age of 4, the growth of the foot length and the plantar circumference decreased year by year. Before 12-13, the growth of the foot was about 7mm, and the length of the plantar circumference was about 6mm. The ratio was 10:8.6.

After reaching adulthood, the body basically stopped growing, and the foot type also stabilized. The ratio of foot length to plantar girth was about 10:7.

For example, from the baby's foot type, it is difficult to distinguish between the baby and the baby's foot type.

As age increases, the difference between male and female foot type is bigger and bigger.

According to the results of the national foot measurement, the average foot length of men is 252.10mm, the average length of women is 232.11mm, and the average length of men and women is about 20mm.

When the foot length is medium foot length, the average plantar circumference of men is 253.53mm, and the average plantar circumference of women is 243.09mm. The difference between males and females is about 10mm.

For example, in Xinjiang, the average length of men's feet is 256.35mm, ranking the first in all provinces, while the average length of men in Guangdong is 248.87mm, which is the smallest in all provinces, and the difference between them is 7.48mm.

The average length of women in Jiangsu is 234.96mm, the longest in all provinces, while the average length of women in Guizhou is 230.02mm, the shortest in all provinces, and the difference between them is 4.94mm.

From the plantar circumference, the plantar circumference of the rural area is more than half of the plantar circumference of the urban area. From the southern and northern rural areas, the southern farming area is more fertile than the northern rural area.

In the same sex, the same area and different occupation, the difference of foot length is about 1mm, while the difference of foot and plantar girth is 5-7mm.

Due to the different nature of work, the force acting on feet is also different.

Normal distribution refers to a larger proportion of medium foot length, and a smaller proportion of the longer foot or shorter foot.

As the saying goes, "jujube arc" is large in the middle.

A normal distribution curve can be obtained by drawing the distribution state into a graph.

Referring to figure 5-1, figure 5-1, the distribution curve of the average foot length of men in China is drawn.

The abscissa is the length of the foot, and the ordinate represents the percentage.

It can be seen from the distribution curve that men's medium feet are about 250mm long.

When making the shoe number, the middle shoe number is based on the largest middle foot length, corresponding to the middle foot 250mm with the middle number 25.

Similarly, the distribution curve of national women's feet length can also be drawn.

With the change of time, the middle foot length can also be changed. At present, people's foot type is long, and the middle shoe number can be replaced by male No. 25.5 and female 23.5.

Although the foot length has changed, the distribution rule of foot length has not changed and is still in line with normal distribution.

The following is an example of men's shoes.

If the shoe number is 25#, the half number is expanded before and after the operation. When 24.5#-25.5# is put into production, its satisfaction degree is: 16%+18%+ 17%=51%

The degree of satisfaction is seen in the shadow of the graph.

If seven shoe numbers are put into production, both from 23.5#-26.5# and 6%+75%+8%=89%.

The degree of satisfaction refers to the degree of meeting consumers' demand for length numbers.

Obviously, the more shoe numbers put into production, the higher the satisfaction will be.

But from the point of view of production, the cost of investment will increase, so the number of shoes that are normally put into operation is 5-6, which can meet 80% of the people's right shoes.

Men's shoes are usually in the range of 24#-27#, taking 25# or 25.5# as the middle.

In order to facilitate production scheduling, a large number of products are divided into small quantities, namely, production units.

Each production unit can be 50 pairs, 30 pairs, 25 pairs, 20 pairs, etc. each production unit should include all shoe numbers put into production, and the number of production pairs of each shoe number should be determined according to a certain proportion.

Next, men's shoes are taken as examples.

The output of each unit can be calculated through conversion.

See table below:

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