Some Scientific Views on Tissue Deformation
In an earlier Post #32 to marinera I said,
“Let's all be honest. What you take for "scientific evidence" is nothing but disjointed extracts taken pell mell from all over the place….
(1) They often involve non-human subjects
(2) When they do involve human subjects, they virtually never deal with the penis - but usually tendons or ligaments, or even skin graftings, etc.
(3) When they do deal with a human penis, its usually in the setting of some pathology: peyronie's disease, chordee, megalophallus, impotence, etc.
(4) Or they focus on ill men suffering impotence due to various ailments: diabetes, MS, hypertension, etc.”
Nonetheless, I’m not averse to looking at any interesting finds….
The following excerpts contain some useful information on heating & force…
From Deformation: Intensity, Method and Recovery - Shiver (July 20, 2004)
"Infrared heat increases the extensibility of collagen tissues. Tissues heated to 45C (112 °F) and then stretched exhibit a non-elastic residual elongation of about 0.5 to 0.9 percent that persists after the stretch is removed. This does not occur in these same tissues when stretched at normal tissue temperature. Thus 20 stretching sessions can produce a 10 – 18% increase in length in tissues heated and stretched."
I don’t think it is important what the heat source is. In the quote that I pasted they were selling Ultrasound machines, which is why they mentioned that method. I think 112 °F is pretty hot, but not too hot to bear I would have thought.
From the research on collagen extensibility it would seem that a long-term stretch under low force would be best (score one for the hangers).
"When stretched, the connective tissues appear to be viscoelastic in nature. When a force is applied against the tissue and then removed, the tissue behaves as if it has both plastic and elastic properties. The elastic response is shown by recovery of the tissue to its original shortened position, while the plastic response is characterized by permanent elongation. Optimal plastic deformation of the tissue results with applications of long periods of low force stretch. The tissue slowly remodels because a biochemical, triggered by constant force, results in a loosening and shifting of the fibers’ connecting point within the tissue." [from Contracture.pdf]
If you look at the research on Ultrasound treatment they also have some points on how much to heat structures for the best results:
"The thermal effects […] on human tissues are well documented, and are utilized to […] increase the extensibility of collagen allowing tissues to be stretched more effectively. […] Tissue temperature need to be raised 3-8° C to obtain the increases in tissue extensibility associated with heating."
And about duration…
"Sapega et al. describe a program designed to lengthen functional connective tissue structures in an a traumatic fashion. They advocate a moderate but tolerable force to stretch contractures for 20-60 minutes, depending on tolerance. The joint is placed at end range. Several 30- second breaks can be used."
Some hints about heat and penetration from various studies I found in the net:
"Far-infrared light can penetrate up to 1 to 1.5 inches where heating pads mostly heat at the skins surface."
About heat packs: "Greatest degree of heating is at 0.5 cm depth from the surface and takes 6-8 minutes to reach maximum."
"Muscle temperature at 1-2 cm depth increases at lesser degree and takes 15-30 minutes to reach maximum."
"Stretching window is 3 minutes. After that the tissue temperature drops past tissue extensibility."
Best heating source, btw, would be infrared, followed by moist heat. Thermotex sells and produces infrared pads, but they are very expensive and don’t have the right size for PE.
Actually one study had this to say regarding that issue:
"In order to deform, and then reform a ligament into a more desirable length and form, the applied "constant" load must reach over 40% of that particular ligament’s "ultimate load". A ligament’s ultimate load is defined as "the final load reached by a structure before failure"."
This is supposedly ideal force so that the fibers don’t revert to their original state but rather remain elongated. (No word on whether heat changes this threshold though.) Now, we don’t know the ultimate load of the tunica and/or ligaments but considering lig pops and other phenomena I’d say that manual stretching, if fairly intense, should at least approach that 40% cut-off.
But the take home message for the high intensity guys is taking adequate time off between sessions depending on the nature of the excercise, and depending on what part of the healing phase the tissues are in. I’ve listed some of the stress amounts listed below, while being high, are withing the realms of hangers and stretchers here.
You can get the full article here.
The stress is divided into four bands which are defined very roughly as follows:
A <80N (<18lbs)
B 80-180N (18-40lbs)
C 180-280N (40-63lbs)
D >280N (>63lbs)
From Connective tissue- FIRST "THREAD OF THE YEAR" - hobby (Aug. 14, 2002)
With any given stretching force, the resulting proportion of plastic to elastic response depends primarily upon two stretching force variables: time and intensity. Research on these variables has produced three significant findings: 10, 16-18
1) Short duration stretching of high intensity favors the elastic response, while prolonged duration stretching of low intensity favors the plastic response.
2) There is a direct correlation between the duration of a stretch and the resulting proportion of plastic, permanent elongation.
3) There is a direct correlation between the intensity of a stretch and the degree of either trauma or weakening of the stretched tissues.
To summarize, the longest period of low force stretch produces the greatest amount of permanent elongation, with the least amount of trauma and structural weakening of the connective tissues. 10, 11, 16-18
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Interesting information – with the understanding that none of it results from any studies on human penile tissue.