Girth theory: Pumping vs. clamping

Thank you. We are in agreement. Though others dispute this. To make sure that everyone else understands, we are talking about making the pressure in a pumping tube positive not negative. This does not necessarily apply to clamping where the areas away from the clamp will distend.

Thank you again. We are in agreement. However the degree of the pressure equalization depends upon the compliance of the vessel we’re sucking on. I can guaranty that at peak erection, the cavernosa pressure dose not become 50 mm Hg if a -150 mm Hg force is applied with a pump..

Thank you again. We are in agreement.

And I agree totally with this.

We may disagree whether a linear peristaltic pump or a mesh should be used to simulate the system, however I agree with you here.

The extent of the wall tension and response to drawing a negative pressure over the penis will definitely be controlled by the wall elasticity (or distensibility or compliance).

To complete my understanding and application of your system, I envision peak erection (because this is a quasi-stable situation). At this point the tunica is stiff. However the applied negative pressure can more than likely affect a volume-induced tension to cause connective tissue remodeling and increased girth. So even at this very stiff point, I can envision enough distortion to make growth possible

I think we are very close to a meeting of the minds.

Good question, (I know that really helps).

The tension-induced connective tissue model that I presented (Possible reason for PE induced growth) does tend to agree with your statement regarding further stress beyond max (say the tunica at peak erection, AGAIN) may cause strengthening, not lengthening. A tendon pulled maximally with muscle contraction (muscle loading) shows a predominant increase in collagen fiber diameter making the tendon stronger, not necessarily longer. This keeps it from being ripped from where it inserts into bone.

This may be the analogous situation of attempting to stretch the tunica at peak erection.

The situation appears to be different when a tendon or ligament is stretched when it is not loaded (the muscle is not contracted in the case of the tendon). We know that ligament and tendon stretch and elongation does occur. Stretching is an important part of overall health. Actual collagen fiber (and other fiber) length increases. This is what gives us flexibility.

This may be the analogue to your jelqing an "unloaded" tunica.

I think your hypothesis is a good one. This expands (or erects) our understanding beyond the static and very specific case of the peak erect tunica (which I think I have a better handle on now; talc always helps) to a more complex discussion of the effects of PE on a constantly changing penis at different stages of erection and therefore different tunica compliances or levels of loading.

The difference between peek erection and the expansion achieved in the tube is that in the last case the dick is open to the circulation, while - as pudendum described so well, in the case of peak erection the dick is closed by (intermittent => see mrvag’s comment and link) muscular activity.

All capillaries get their blood from the arteries, just as the corpora cavernosa do.

That is indeed an important comment I was not aware of. Since I have two tubes, which I am using on different days (the smaller one for length, the bigger for girth) I want to give it a try soon.

Thanks for the suggestion.

If you practice adc some of the expansion is fluid accumulation under the skin (that’s what I experience), some is tunica expansion. What I like most is the expansion of my glans from adc. It apparently has a quite different dynamic compliance than the tunica.

Probably no big difference:

If you start unerected the blood will be pulled in until there is pressure equilibrium. If you get in erected the vessels open toward the body and again, blood is shifted until pressure equilibrium.

Considering your lack of interest in penis physiology I would like to compliment you about digging out a very interesting paper with high relevance to our topic.

Btw - I found it fascinating that voluntary contraction of the same muscles does not increase cavernous pressure. Penis physiology IS fascinating, after all - mravg?

I think the paper quoted by mrvag says it all: invasive measurement, and yes, due to muscular activity (only involuntary!) cavernous pressure rises above arterial pressure.

And: this effect is intermittent, has to be intermittent, in order to protect the intracavernous structures from ischemic damage.

tt - Invasive measurement is important and this study showed very good design for the hypothesis they asked.

Remember what you said about experts. You must be able to differentiate what they confirmed by their results and what they propose in their discussion. I know this is a fine point, but it is an important one as well.

They show that cavernosa pressure is not always elevated above arterial pressure (supra-arterial as they called it) throughout the peak erection phase with intermittent changes associated with Ischiocavernosus and Bulbocavernosus muscle contraction. This definitely bucks the mainstream thought here. Their data are good. I would have loved to see a trace of the time course of pressure fall off when these muscles relaxed as they nicely showed with pressure rise (call me a skeptic).

This study was preformed in awake individuals with drug induced erection (could you imagine trying to get a spontaneous erection wired up the way they were?). A very important prior study, which they do not quote, was published in the journal Science in 1983. It looked at volunteers at night with spontaneous nocturnal penile tumescence (which we know as “night wood”). These authors chose to study this type of erection because it is spontaneous, normal and reliably repeatable (at least that what PI’s tell us). The authors measured Ischio- and Bulbocavernosa muscle activity (on the skin, not with needles), blood flow with an external monitor around the penis (a validated method), and penis circumference at the base and below the glans. (Note: They too did not look at blood flow in the veins leaving the cavernosa).

This older study also found intermittent contractions of the Ischio- and Bulbocavernosus muscles. But, they found them during the filling phase of the erection (which the present study did not see). They also saw that these contractions were the longest and the strongest at maximum circumference (peak erection). When these contractions abruptly went away, erection starts to soften and go away.

They concluded:

Note their conclusion is totally different than from the present study. It is more in line with what they measured and studied.

Is there a difference between a spontaneous night erection and one induced by a drug injected into the cavernosa while the penis is wired for sound? Ahh, let me think about that a second…Dah, do you think maybe!. All of the above the shoulder influences (either when awake or asleep) in the erection process are important. Do you think that maybe the guys with needles in there penises were a little distracted and that having an erection was the last thing on their mind? Do the differences in the contraction patterns of these muscle in these two studies differ because of this? I think it it more than likely and might influence pressure measurement results as well. Again, call me a skeptic, but that’s what I am.

However, I agree that absence of pressure rise with kegels is very surprising and may turn our idea that this brings more blood into the erectile chambers on its ear. It is possible that there are volume changes without pressure changes as the penis becomes more erect, but this cannot be the case with peak erection. This the real hot news for us here and we need to reevaluate our methods in light of this.

I’ve been thinking about this a lot since I first read this. I think that Sparkyx is on to a very important point here. In fact, I think this concept might be so important as to take us further down the road towards the Holy Grail of PE: why and how do we grow.

Yes Sparkyx, wall tension is everything. As I noted in the thread on the connective tissue mechanisms of connective tissue remodeling (Possible reason for PE induced growth), tension is the most important stimulus. The question we all ask is: what type of tension and how intense?

Tension is tension, no matter the cause. But how this tension is generated and when is important.

There is a very important and simple principle known as LaPlaces’s Law that describe wall tension (which tunica stretch is).

OH NO, not another scientific explanation!!! Please bear with me, this is actually simple and important. I’ll make it simple.

If you have a tube (like the cavernosa) with a radius, r, with a wall (like the tunica) with a thickness, M, with an internal pressure, P, then you can describe the tension on the wall (the tunica), T, by the following equation:

T = P * r/M. [Tension on the tunica = (radius of the cavernosa X cavernosa pressure)/tunica thickness]

Let’s assume that tunica thickness does not change, so M is constant (it may not be but for giggles and grins, let’s assume it is). Therefore, tension increases by increased pressure, radius or both.

Sparkyx comments on stretch when the tunica is stiff versus when the tunica is flexible is explained well using this law.

When the tunica is tight, at peak erection, the radius change is very small. Depending upon the method you use, clamping, bending or pumping, the change in pressure is variable. In this case, the tension is bumping up against a tunica that just can’t stretch much more. The tunica does not "want’ to rupture with these kinds of stresses in the future, so the tension-induced stretch (like in the case of the muscle loaded tendon stretch) causes a connective tissue remodeling which increases collagen fiber diameter and not length. The tunica therefore becomes stronger and resists stretch even more.

When the tunica is flexible in the semi erect penis when you jelq, pressure and radius both increase in the power stroke of the jelq. This stretch in a more lax state of the tunica is like the unloaded (muscle relaxed) stretch of tendons and ligaments for flexibility. This could lead to the elongation of circular tunica fibers and cause girth expansion. This is tension generated against a flexible and movable tunica, which is why I think jelqing is so effective.

I would think pumping’s effect in the semi erect penis would be almost entirely through increases in radius, as pressure in the tunica may either stay the same or even drop because of the negative pressure effect on the cavernosa of an incomplete erection.

So PE work on a loaded or unloaded tunica is entirely different and may have a different result. I think this is very important and we need to think about this.

Thank you Sparkyx.

Scientific is fine; simple is fine too. Sensible has to be ubiquitous.

Fair enough. I agree with your ultimate idea.

I just have trouble with this:

Perhaps I’m nit-picking, but I find this suspect. It may be too simple.

It seems to assume all things are equal (if it doesn’t make that assumption perhaps you could further elaborate). To my way of thinking they aren’t; a wall of steel is different than a wall of clay, as a rule. You would need very different thicknesses of these two materials to have your equation work.

Granted with human physiology there are limited variables, but those variables have to be expressed in a range. My bone density would likely not be identical to a 18-year-old’s or a 70-year-old’s, for example. I would guess there were some variation with each individual tunica as well, which would account for the variations of success or failure to gain from one or the other (or even any) method.

I basically agree that a semi-erect state is where the penis has the best chance of being ‘molded’ and influenced by force. Too much force means shock and recoil and, as you pointed out, and toughening of collagen fibers.

I think I also missed you point about the low level erection pumping. Are you saying the efficacy is made greater or lessened by the more uniform pressure the pump exerts?

Please advise.

It is a simple principle. Sometimes the simplest explanation is the best.

It has been used to explain many things in the body. It is an important concept to understanding the stretching of blood vessels when blood volume increases as when you eat too much salt. The vessels (particularly small vessels) distend by pressure, increasing the vessel radius which results in elevated vessel wall tension. Over a short period of time, the smooth muscle of the vessel wall relaxes to relieve the tension. The tension is relieved and pressure is decreased at a larger vessel radius. This is the stress-relaxation process that keeps blood pressure stable over the short term (See Arthur C. Guyton’s Textbook of Medical Physiology).

With the tunica it takes us back to the compliance of the tunica at different phases of erection.

I think the effect of pumping is due to the tension increase by the increased volume in the cavernosa at a lower level of erection that increases cavernosa radius and increasing tunica tension at a higher compliance (more distensible), which equals unloaded stretch.

I think long sustained pumping with a uniformed pressure is the key. You’re holding the wall tension high at an increased radius and stimulating connective tissue lengthening (in the circular fibers of the tunica, lengthening = increased girth).

A few observations:

A number of us here at Thunders have commented that our firm, nocturnal erections are very often girthier than our conscious, sexual ones. They feel thicker in the hand; I’ve even gone so far as to measure a few of them in the night and came up with about .25 inch more girth than my measured daytime erections. Also, it’s been noted by others that an eighty or ninety percent conscious erection is often fatter than a totally firm erection.

In the case of nocturnal erections it seems logical that the parasympathic nervous system, which is definitely pro-erection in one of its functions and takes over while we are unconscious, allows for some unusual outward deformation of the tunica than does the sympathetic nervous system. In the case of a conscious erection at, say, 80 percent, the tunica is clearly less rigid and so jelking and modified Ulis are more PE-productive than when we become yet more erect.

The implication here is that my tunica, and maybe yours, is capable right now of expanding to hold more cavernosal volume than it usually does when I have a firm erection.

Trick is, 1) how to get that 1/4th inch, or whatever, all the time :) and 2) how to get the tunica to relax yet further to make girth increase easier. OR, to cause the tunica sheath to grow wider and longer.

I totally agree here—this makes perfect sense.