Full Body Cracking

[richardg]

Anyone knows any place in SG can do this?
looks so shiok.

https://www.facebook.com/BackCrackin...4576500755246/
https://www.facebook.com/LifeAndArtC...1839358590611/

[Ong88]

DIY?

Safer

[richardg]

Originally Posted by Ong88

DIY?

Safer

DIY??
cant la, how? need another person leh

[Guppies Onli]

BMT
Last time ITD BMT to me is full body cracking and breaking

[bedoklist]

There is this person call leong from malaysia. He goes around country to country to do this. FB at https://www.facebook.com/wahtohtittar/

[loveikan]

Originally Posted by bedoklist

There is this person call leong from malaysia. He goes around country to country to do this. FB at https://www.facebook.com/wahtohtittar/

This guy known as Master Chris is really good. Pick up some tips from him via his many videos.

[Ong88]

Originally Posted by richardg

DIY??
cant la, how? need another person leh

Just do it yourself.

Tomorrow free, I make video.
Lumbar, fingers, toes.
Big toes and lumbar spine can be done hands-free.
Other toes and fingers, need hands to crack.

Neck I don't do, dare not. Not even cheo masseuse allowed.

Cracking actually just (Nitrogen?) gas bubbles in our joints that we burst, iirc. Cmiiw.

[Ong88]

YouTube Video

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4398549/
Real-Time Visualization of Joint Cavitation


Abstract
Cracking sounds emitted from human synovial joints have been attributed historically to the sudden collapse of a cavitation bubble formed as articular surfaces are separated. Unfortunately, bubble collapse as the source of joint cracking is inconsistent with many physical phenomena that define the joint cracking phenomenon. Here we present direct evidence from real-time magnetic resonance imaging that the mechanism of joint cracking is related to cavity formation rather than bubble collapse. In this study, ten metacarpophalangeal joints were studied by inserting the finger of interest into a flexible tube tightened around a length of cable used to provide long-axis traction. Before and after traction, static 3D T1-weighted magnetic resonance images were acquired. During traction, rapid cine magnetic resonance images were obtained from the joint midline at a rate of 3.2 frames per second until the cracking event occurred. As traction forces increased, real-time cine magnetic resonance imaging demonstrated rapid cavity inception at the time of joint separation and sound production after which the resulting cavity remained visible. Our results offer direct experimental evidence that joint cracking is associated with cavity inception rather than collapse of a pre-existing bubble. These observations are consistent with tribonucleation, a known process where opposing surfaces resist separation until a critical point where they then separate rapidly creating sustained gas cavities. Observed previously in vitro, this is the first in-vivo macroscopic demonstration of tribonucleation and as such, provides a new theoretical framework to investigate health outcomes associated with joint cracking.

Introduction
Background
Sounds emitted from human synovial joints vary in their origin. Joint sounds that occur repeatedly with ongoing joint motion arise typically when anatomic structures rub past one another. In contrast, “cracking” sounds require time to pass before they can be repeated despite ongoing joint motion. Although various hypotheses have been proposed over many decades regarding the origin of cracking sounds, none have been validated; the underlying mechanism of cracking sounds remains unknown.

History
In 1947, Roston and Wheeler Haines [1] published the first scientific study toward describing the origins of joint cracking. Their experiment used serial radiography to visualize joint cracking when distraction forces were applied to metacarpophalangeal (MCP) joints. Their results characterized the sequence of gross articular events that define joint cracking. The process begins with the resting phase where joint surfaces are in close contact. In this stage, a light distraction force will barely separate the joint surfaces. With a greater distraction force, the surfaces resist separation until a critical point after which they separate rapidly. It is during this rapid separation phase that the characteristic cracking sound is produced. Following cracking, the joint is in a refractory phase where no further cracking can occur until time has passed (approximately 20 minutes). Importantly, post-cracking distraction also reveals the presence of a “clear space” assumed by Roston and Wheeler Haines to be a vapour cavity. This cavity, described by some as a bubble, has been thought to form as distraction forces decrease pressure within the synovial fluid to the point were dissolved gas comes out of solution. Importantly, Roston and Wheeler Haines linked the production of the cracking sound to the formation of this clear space, a phenomenon first described in 1911 [2] but thought by some to occur only in unhealthy joints [3] until demonstrated to also occur in normal joints[4].

This interpretation of joint cracking stood as the standard for 24 years until 1971 when Unsworth, Dowson and Wright [5] refuted this view by stating that the exact mechanism of joint cracking “was in doubt”. Although Unsworth et al. used a similar radiographic procedure to confirm the same sequence of events described by Roston and Wheeler Haines, they arrived at a different conclusion. Specifically, Unsworth et al. speculated that the formation of a clear space, or bubble, was not the source of joint cracking, but rather cracking was caused by the subsequent collapse of the bubble. This idea was likely influenced by the realization that bubble collapse could cause damage in surfaces adjacent to the bubble itself [6]. First described by Rayleigh in 1917 [7], cavitation collapse came into the fore in the late 1960s as a source of significant damage in marine equipment [6] such as propellers, hydrofoils [8].

As a result, publications since 1971 have referenced Roston [9–11] or Unsworth [12–24] or both [5,11,25–39] when describing joint cracking. Adding to the confusion, others [25] have suggested that sound produced during joint cracking occurs through ligamentous recoil. Still others [18,19,25,26] advocate for an additional mechanism known as viscous adhesion or tribonucleation [40,41], a process that occurs when two closely opposed surfaces are separated by a thin film of viscous liquid. When these surfaces are distracted, viscous adhesion or tension between the surfaces resist their separation. Then, as distraction forces overcome the adhesive forces, the surfaces separate rapidly creating a negative pressure. This negative pressure, combined with the speed with which the surfaces separate, can create a vapour cavity within fluid much like a solid that has been fractured [42–44].

Unfortunately, no direct evidence exists to resolve these differing perspectives regarding the mechanism of joint cracking. While many have used various radiographic means to record events associated with joint cracking [1,5,10,45], these techniques have a number of limitations which conspire to obscure intra-articular events due to low space-time resolution, insufficient contrast and superimposition of structures.

Given the above, the objective of this study was to characterize the events associated with joint cracking within the joint itself using real-time cine magnetic resonance imaging (cine MRI). Here we present direct evidence from cine MRI that the mechanism of joint cracking is related to cavity formation rather than bubble collapse.


....
.....
.......
Conclusions
Our data support the view that tribonucleation is the process which governs joint cracking. This process is characterized by rapid separation of surfaces with subsequent cavity formation, not bubble collapse as has been the prevailing viewpoint for more than a half century. Observed previously in vitro, this work provides the first in-vivo demonstration of tribonucleation on a macroscopic scale and as such, provides a new theoretical framework to investigate health outcomes associated with joint cracking. This framework will allow scientists to compare and contrast this process against tribonucleation observed between inanimate surfaces, an approach that may reveal how joint cracking affects cartilaginous joint surfaces. Presently, the literature in this area is confusing in that the energy produced during joint cracking is though to exceed the threshold for damage[51], but habitual knuckle cracking has not been shown to increase joint degeneration [52]. Ultimately, by defining the process underlying joint cracking, its therapeutic benefits, or possible harms, may be better understood

[Ong88]

https://www.scientificamerican.com/a...he-sound-when/


What makes the sound when we crack our knuckles?


Raymond Brodeur in the Ergonomics Research Laboratory at Michigan State University responds:

To understand what happens when you "crack" your knuckles, or any other joint, first you need a little background about the nature of the joints of the body. The type of joints that you can most easily "pop" or "crack" are the diarthrodial joints. These are your most typical joints. They consist of two bones that contact each other at their cartilage surfaces; the cartilage surfaces are surrounded by a joint capsule. Inside the joint capsule is a lubricant, known as synovial fluid, which also serves as a source of nutrients for the cells that maintain the joint cartilage. In addition, the synovial fluid contains dissolved gases, including oxygen, nitrogen and carbon dioxide.

The easiest joints to pop are the ones in your fingers (the interphalangeal and the metacarpophalangeal joints). As the joint capsule stretches, its expansion is limited by a number of factors. When small forces are applied to the joint, one factor that limits the motion is the volume of the joint. That volume is set by the amount of synovial fluid contained in the joint. The synovial fluid cannot expand unless the pressure inside the capsule drops to a point at which the dissolved gases can escape the solution; when the gases come out of solution, they increase the volume and hence the mobility of the joint.

The cracking or popping sound is thought to be caused by the gases rapidly coming out of solution, allowing the capsule to stretch a little further. The stretching of the joint is soon thereafter limited by the length of the capsule. If you take an x-ray of the joint after cracking, you can see a gas bubble inside the joint. This gas increases the joint volume by 15 to 20 percent; it consists mostly (about 80 percent) of carbon dioxide. The joint cannot be cracked again until the gases have dissolved back into the synovial fluid, which explains why you cannot crack the same knuckle repeatedly

But how can releasing such a small quantity of gas cause so much noise? There is no good answer for this question. Researchers have estimated the energy levels of the sound by using accelerometers to measure the vibrations caused during joint popping. The amounts of energy involved are very small, on the order of 0.1 milli-joule per cubic millimeter. Studies have also shown that there are two sound peaks during knuckle cracking, but the causes of these peaks are unknown. It is likely that the first sound is related to the gas dissolving out of solution, whereas the second sound is caused by the capsule reaching its length limit.

A common, related question is, Does popping a joint cause any damage? There are actually few scientific data available on this topic. One study found no correlation between knuckle cracking and osteoarthritis in the finger joints. Another study, however, showed that repetitive knuckle cracking may affect the soft tissue surrounding the joint. Also, the habit tends to cause an increase in hand swelling and a decrease in the grip strength of the hand.

Another source of popping and cracking sounds is the tendons and ligaments near the joint. Tendons must cross at least one joint in order to cause motion. But when a joint moves, the tendon's position with respect to the joint is forced to change. It is not uncommon for a tendon to shift to a slightly different position, followed by a sudden snap as the tendon returns to its original location with respect to the joint. These noises are often heard in the knee and ankle joints when standing up from a seated position or when walking up or down the stairs.

[Ong88]

https://www.coreconcepts.com.sg/arti...now-about-vbi/

If you like getting your neck ‘cracked’ or thinking about it, you should know about VBI

It is not uncommon to find people in Singapore that enjoy a good crack of the neck once a while. It was particularly special way to end a hair-cut in the good old days at now-almost-extinct indian barber shops. There are also those who pop in to some massage or "chinese-sensei" shops that do these 'bone-cracking' service.

Some do it because they enjoy the loose-ness of the neck area. Others do it because they were informed that it is good maintenance to do so to keep the neck loose.

But often they are not aware of the serious risk that they face. The risk of Vertebrobasilar insufficiency (VBI), or vertebral basilar ischemia to be exact. VBI is temporary reduction in the blood flow to the back of the brain.

In other words a stroke

VBI like other forms of stroke can be caused by blood clots, narrowing of the vessel from cholesterol or any other reasons for a reduce blood flow through the artery. A less common cause is mechanical forces, particularly in the neck region, that apply pressure on the verterbral arteries or in the worse case scenario, severe it. Particularly when the neck is cracked at its end of range. The danger lies if the technique is poor and not precise, i.e. many cracks rather than just the one intended. This puts a lot of sheer or traction force on the artery, possibly leading to tears or occlusion of the blood vessels. See diagram for more details on the anatomy.

Also to note, that the 'cracking' or manipulation in this article refers to the manipulation of the neck. It is generally consider safe to manipulate the thoracic or lumbar spine, that's the mid and lower back. Before manipulating the cervical spine, the practitioner should first perform a test for VBI symptoms