Both parents are very concerned about the baby’s future [altitude].
Some parents think that the baby’s arms will be long and will not be too short in the future.
Some parents look at their baby’s thin and long fingers and judge that their baby will be tall in the future.
Are all these judgments reliable?
We invited Doctor Sun Yueli to tell us three truths about height.
The longer the legs, the taller the height.
The principle of this is very simple, the bone that dominates the height of people is mainly the femur (thigh) and tibia (lower leg) of lower limbs, so the longer the leg, the higher the height, this inference is not wrong. Moreover, in the same race, the proportion of most people is certain, so the approximate height can be estimated according to the length of tibia and femur of lower leg or thigh.
The longer the arm span, the taller the height.
Similar to the structure of femur and tibia are ulna (forearm) and humerus (upper arm), which belong to [long bone] in the bone category.
The length of the long bone is larger, In addition, there are abundant blood vessels distributed in the middle bone, and there is a hollow structure in the middle, which is called [medullary cavity]. A small number of blood vessels are distributed at both ends of the bone, often growing into nodular protrusions. Because of the distribution of medullary cavity and abundant blood vessels, the growth potential and speed of such bones are very fast, and the growth also tends to be synchronous.
As to why the arms do not grow longer than the legs, it is because the human genes are designed early before birth. Through the complex and precise adjustment of hormones and proteins, the limbs will tend to be stable in the process of growth and development and maintain a relatively consistent proportion.
The longer the hands and feet, the taller the height is not necessarily.
Looking back, we have also heard some tips for predicting height, such as [feet grow tall], [fingers grow tall], etc.
There are even some studies that have carefully calculated the formula for the correlation between the size of hands and feet and height. For example, the height of boys is equal to the length of feet and hands multiplied by several, while the height of girls is equal to the length of feet and hands multiplied by several.
These are not reliable from the [God’s perspective] of bone growth and development. Because the bone types of phalanges and soles belong to [short bone] and [flat bone], their structure is very different from [long bone], and they lack bone marrow cavity and rich blood vessels to supply nutrition for them.
At the same time, the bearing direction of [short bone] and [flat bone] is also different from that of [long bone].
The force borne by [long bone] mostly comes from axial direction, while the force borne by [short bone] and [flat bone] varies in direction.
Finally, at the most important level of gene regulation, the growth and development of hand and foot bones and limb bones are not directed by a class of genes, so there is no synchronization and correlation between them, and the multiple of those correlation varies from person to person and has no reference and prediction value.
Therefore, the bigger the feet, the longer the fingers, the higher the height.