THE MECHANICS OF MALE PATTERN BALDNESS:

You know, I'm going to stop here for a moment and tell you what got me started investigating in this direction. What would cause the scalp to be shiny? By pulling it tight against the skull. It seems that the one thing that all the practitioners in their field of M.P.B. might grudgingly agree to is that the scalp can be tight. Why hasn't anyone asked the question how can a scalp be tight and then proceed to look into it to see if there might be some connection? This made me wonder about the nature of stress. What is it?

I think I've come up with a tidy definition.

Stress is the resistance to or against something approaching, present; or departing. All things departing were once present and all things present were once approaching. Look at your own life, and every scenario can be distilled to this basic.

OK, do I hear the grinding of teeth?; A little too much of the obvious? Hang in there folks. Now our story takes an interesting turn. We now are going under the skin of the head. Where we stop is at the galea, that tendon like membrane that the scalp is bonded to. Here we see the bilateral symmetry (both left and right sides alike) of the small muscles that attach to the galea.

I've included an illustration from some anatomy books for credibility; but Nate Pitkins' illustrations really communicate the situation. Figure (3).

As an aside, I was wondering what the galea and its attaching muscles were designed for. Possibly the pumping of spinal fluid prior to the hardening of the sutures of the skull?

But I'm drifting, ...back to the story.

Underneath the galea separated by a thin membrane we see the large muscles that close the jaw and that this muscle mass climbs quite a ways up each side of the skull. Interestingly, it appears that the front attachment of the galea to the muscles of the forehead looks surprisingly like the line of a normal hairline. In other words, the normal hairline follows exactly the line where the galea attaches to the muscles of the forehead.Figure (4).

In profile, we see the clamshell shaped muscles that attach the galea to the side of the head. Please note the shape of these muscles. They are fan shaped so that when contracting, they exert a pull across an area of almost 150 degrees. Figure 3

On the back of the head we see the two muscles attached to the galea exactly where the flat plates of the skull end and the sharply curved dome of the skull begins. Figure (3) and Figure (5).

Also, of major importance to this theory are the muscles that attach to the back of the ear. In some people these muscles are under voluntary control and they can move their ears at will. Figure (3) and Figure (5).

My theory, according to what I have been able to observe of the male pattern and the underlying structure of the galea, its muscle attachment points and the shape of the skull is this:

The scalp and its capillary bed are bonded to the galea, which actually floats over the skull and is only attached to the skull by the muscles described above. These muscles, for some reason, arrive in a state of continuous contraction. Because of the mirror image placement (left and right side) of these muscles, as they contract, they create a down force by tightening the galea/scalp unit against the curve of the skull sufficient to impede blood flow to the hair follicles.

If you were to remove the curve of the skull and could see the opposing attachment points across a flat surface, it would look exactly like the attachment and tightening points of a drumhead. Kind of makes me think of a reverse Eskimo blanket toss thing. Only instead of Eskimos twanging one of their fellows into the air, these muscles attached to the galea are trying to twang you into the ground and the only thing that happens is you lose your hair.

Let’s start with the fan shaped muscles on the sides of the head. When it contracts, it's pulling along a 150-degree radius inward toward one point. Figure 3 and Figure 6

Well, on the opposite side is the mirror image muscle doing the exact same thing. When this tug of war is done over the curved surface of the skull, you get some interesting down force multiplication. Figure (1).

Let’s apply this theory to the pattern and see if it works. If you were to have two equal and opposite forces being applied across a curve, where would the force be greatest? At the exact center or highest point of the curve. Where does the bald spot start? At the center! As it grows, it radiates symmetrically. Why is it that when these muscles contract over the flat plates of the skull there is no hair loss? No curve, no down force, no blood flow impediment. You remember those muscles I mentioned earlier? The ones behind the ears that pull them back? Well, when those contract, guess where the slack gets taken up. Right, these amplify the down force exerted by the side muscles enormously.

Now let's take a look at how the side muscles affect the crown of the head. Apparently, this kind of never ending muscular contraction is called Biological Tension. In the case of hair loss, it only has to be great enough to defeat the push of normal blood pressure. When that happens, no nutrients in and no waste out. The follicle starves to death.

Let's go back to looking at the mechanics of the structure for a moment. Where the scalp/galea bond ends along the forehead, the fatty layer and capillary bed are at their thinnest. Figure 1.

To use an example, think of when you've climbed into a bed where the top sheet is very tight and your feet are taking positions you never thought they could. Where is this sheet tightest? At your feet where it curves down and under the mattress. Where is male pattern baldness usually first noticed? At the crown and temples. Let's use the pattern itself to explain how the side muscles affect blood flow to the scalp. It's interesting to note that in so many cases of M.P.B. at the crest of the skull there appears to be an area at the exact center where the hair is thinner or nonexistent and that is bordered on each side by hair that is a little thicker. Figure 1. This balder area is usually 1/4 to 3/4 inch in width.

Back to the example of the tight sheet but this time stick the hood of a '37 Buick with the nose toward the foot of the bed. Where is the sheet tightest? At the hood ornament! It appears that most skulls have this raised crest of bone and that introduces a higher elevation and a sharper curve and this multiplies the down force even more. Hence, less blood flow equals faster hair loss along the crest than along the bordering sides.

All right, let's move on to those pesky muscles at the back of the head. Figure 3 and Figure 5.

Now it's interesting what happens when these muscles haul down on the galea. Because of the geometry of the skull, (some what egg shaped looking at it from the top) when the left side contracts, the resistance occurs where the galea attaches over the right eye and right temple. Vise versa for the right side. It's interesting that these muscles pull back in an "X" configuration. Right back pulls left front, left back pulls right front. Figure 1 and Figure 5.

Because of this cross pull on the scalp, and due to the topography of the skull sometimes you will see those little "islands" of hair at the crown of the head where the counter forces neutralize each other. (David Letterman). Figure 4.

Once again, back to the bed sheet analogy. The pull of the muscles on the back of the head squeezes the scalp down against the curve of the skull along the attaching line at the forehead and temples where the scalp is thinnest.