Why are old people in anime so short?

Miniature senior citizens in Anime

It’s a rather common occurrence in anime that if a character is human and very old, they will also be extremely small.  This lack of size will be a result of their advanced age and not because they were small all their life.

Young Cologne

Ranma 1/2

 

Old Cologne

Miniature senior citizen

 

Now I will grant you that Cologne is a rather extreme example of the old prune but my point still stands.

 

“But don’t people get a little smaller as they age?”

Yes, you are indeed correct that everyone will shrink a little bit as they age, but the question is why and how much, so as to prove that anime is taking things a bit too far.

 

Shrinking in Old Age

Once you pass the age of 40 you can begin to lose some height as you continue to age.  In most people, this is around ½ an inch per 10 years and stays the same till you hit 70 when the rate of loss increases slightly.  However, you should only lose somewhere between 1 to 3 inches in total height.  Losing more than 3 inches or losing height at a faster rate than 1/2inch per 10 years can be a sign of more serious health conditions such as osteoporosis or degenerative disc disease.  The actual loss of height is due to three factors:

1- shrinking of intervertebral discs

2- changes in posture

3- flattening arches

 

Intervertebral discs

The intervertebral discs are cartilage pads that are found between the vertebrae in our spinal column.  The discs play several roles in the normal functioning of our spinal column including movement, holding the spine together, and most importantly as a shock absorber.

miniature senior citizens

 

While the disc is made of cartilage, it is nothing like the cartilage in our nose and acts more like the fancy gel insoles people put into shoes to make wearing them more comfortable.

 

The intervertebral discs have two main components, the annulus fibrous, a thick fibrous bag that surrounds the second component, the nucleus pulposus which has a gel like consistency.  It is the nucleus pulposus that provides the shock absorbing ability of our spine.  While both parts of the disc degrade with age, the dehydration of the nucleus pulposus is what causes the majority of the loss of height seen with age.

 

Each disc is 7-10mm thick and the spinal column has 23 of them.

 

So, a loss of 1mm of thickness in each disc would lead to a 2.3cm loss in height, or almost an inch of height.

 

2- Change in posture

Posture or body position can change overtime due to health, fitness, age, and a host of other factors.  The human body loses bone and muscle mass as it ages, and in this case I will be focusing on the loss of muscle mass.  A lack of proper diet and exercise can weaken the muscles of the back and shoulders causing a change in posture, which can sometimes be referred to as computer body.

miniature senior citizen

 

This hunched position can make you appear shorter than you are and as the muscles weaken it becomes harder to hold the correct posture.  This type of posture change is not limited to adults working desk jobs as I have seen in it in young teens due to spending too much time at a computer.  Unlike the shrinking of the intervertebral discs, height loss from poor posture can be corrected through exercise and training.

 

3- Flattening Arches

The arch of the foot is formed by bones and ligaments, and it does indeed perform a function for the body.  The arch of the foot improves the body’s ability to carry all of the weight of the body in the upright position with the least amount of energy and discomfort.

 

FYI- It is estimated that about 20-30% of the population do not develop arches and considered flat footed.  The environment is thought to play a small role in this as footwear or the lack thereof can influence the muscles that support the arch.  Going barefoot or wearing sandals causes those muscles to work more helping to develop the arch, while close-toed shoes do not.  This can be carried forward and arch building exercises can be done to help prevent the arch from decreasing as the individual ages, preventing a loss of height.

 

Conclusion

Yes, we humans do shrink as we age but not nearly to the degree as seen in many an anime, so I have to call the miniature senior citizen busted.  If you are looking for a more realistic take on people shrinking as they age, check out Avatar the Legend of Korra.

 

Science Extra

Osteoporosis is a bone condition commonly found in the elderly, especially women, that is a result of a loss of a significant amount of bone mass.  The term osteoporosis actually means porous bone and is best explained by the picture below.

 

The loss of bone mass makes the individual more susceptible to broken bones and it is often a silent condition that remains unknown until a bone is broken.  As mentioned above, osteoporosis is one of the conditions that can exacerbate height loss as a person ages.  How this happens is that the vertebrae weaken overtime as they lose bone mass like the other bones of the body.

 

The bones can weaken to the point that they can no longer support the weight of the body and fracture shortening the spine, and changing the individual’s posture.  This is why some older individuals develop a hunch, or as it is called in medicine a dowager’s hunch.