the scientific evidence-base
for spinal decompression

The scientific evidence-base for do it yourself spinal decompression is growing by the day

Do it yourself spinal decompression provides an agreeable sense of pulling the spinal segments apart that seems to feel right. There's a growing body of evidence indicating that these agreeable sensations are well-founded in science. Various researchers tell us that sustained compression of the low back is bad for the discs. 

these are the bare facts on the scientific evidence-base for spinal decompression:

Sustained compression makes the soft-tissue fibres of the disc wall thicker and less compliant (Bernick et al 1991) and therefore easier to injure. Sustained lumbar compression also chokes down the internal metabolic vigour of the discs (Iatrides et al 1999, Stokes 2004, Unglaub 2005, Adams 2006) making them sleepy and sluggish and less able to carry out running repairs. The scientists also tell us that sustained compression expels too much fluid and dehydrates the discs (McMillan et al 1996, Arun et al 2009). 

For all the above reasons combined, discs break down sooner in life than any other structure in the human body (Adams and Dolan 2005). In short, spinal compression is the reason why back problems are so prevalent.

Vertebral compression of the lumbar base is ever-present - and the root cause of everything

One can extrapolate that excessive spinal compression in our everyday circumstances is brought about by sedentary Western lifestyles. One may also reasonably assume that principles of redress (through pulling the spinal segments apart) are rooted in similarly simple scientific facts. 

Step 1 of the BackBlock routine pulls the spinal segments apart, more so at the front

Science tells us that spinal decompression, or traction, brings about raised disc height through increased water retention (Kraemer et al 1985, Magnusson et al 1996, Schnake et al 2006). Scientists also say that higher water pressures inside the discs stimulate their metabolic activity (Ishihara et al 1996, Urban et al 1997, Handa et al 1987, Bayliss et al 1998, Hutton et al 2001) and thus the biological health of the discs. Possibly even more importantly (from the perspective of back pain prevention) scientists also tell us that stretching healthy discs makes them more resilient and less susceptible to damage caused by compression (Lotz et al 2008). German researchers are even more enthusiastic about the regenerative potential of traction on degenerated discs (Kroeber et al 2005, Guehring et al 2006) while others (Lai & Chow 2010) cautiously state that 'gentle decompression can potentially slow disc degeneration’. 

As much as possible, proper science should underpin all spinal treatments, both conservative and surgical

The scientific principles underpinning The Sarah Key Method for treating low back pain are easy to understand

The basic science of this is easy for you to harness for your own good. When doing your own little decompression regime at home every night, you can be safe in the knowledge that you are acting on sound scientific principles. And here's the funny thing: knowing and visualising what is going on in there actually makes the treatment work better!

This applies to Steps 1, 2 and 3 of the 'Pressure Change Therapy' regime. For Step 2, you will visualise pulling tide after tide of fresh fluids through the back wall of the lumbar discs (Adams and Hutton 1983, Tyrell et al 1985).

You can also feel confident that this fluctuating traffic of fluid flow will be providing good maintenance to the needy back wall of the lumbar discs. At the same time, these rhythmic oscillations will be pushing waste products out of the discs and thus dissipating any acidic build-up that slows metabolic vigour. 

Just you thinking about the body's metabolic processes improves the performance of those processes

A huge part of the treatment is visualising what is happening in your back as you do it. It's not only calming and relaxing; it helps the physiological processes happen. In the therapeutic world, we know that focusing the mind measurably up-regulates the body's internal activities. In other words, thinking and visualising about what you're doing makes it happen better. 

The gentle rhythmic knees rocking oscillations to approximately 10% of tensile strain (Lai and Chow 2010) is also put to good effect in repairing ligamentous damage of the posterior disc wall. The rocking rhythm of slightly faster than 1Hz, (one cycle per second) is the lulling-rocking rhythm that the body most responds to, just like rocking a baby to sleep in a pram.  

See the online Sarah Key Store for the downloadable videos taking you through
the careful steps of spinal decompression 

Step 2 of the BackBlock routine helps circulate discal fluids

Step 3 of the BackBlock routine strengthens deep and intermediate layers of the abdominal muscles

Incidentally, we have done our own real-time ultrasound studies and found that 'reverse curl ups' (Step 3 of the Pressure Change Therapy routine) most effectively activate the deep and intermediate layers of the abdominal muscles. We have established that reps of 15 is the most effective number of reverse curls to accompany each 60 seconds on the Block.

Seeing Sarah showing you on video 'How to Do the BackBlock' is undoubtedly the best way of going about things. Remember, when you know what you're doing and feel confident about it, it works better. You can download them here

the Abstracts of sarah's 2 Academic papers

'Healing of painful intervertebral discs: implications for physiotherapy Part1 - the basic science of the intervertebral disc' 

(Stefanakis, Key, Adams)


Background: Population studies show close associations between intervertebral disc degeneration and back pain, with structural changes such as annulus tears being most closely related to pain. However, little effort has been made to link back pain to disc injury in individual patients, or to treat the disc injury in a similar way to a ligament or tendon sprain.

Objectives: To re-interpret the scientific literature in order to provide a rationale for physical therapy treatments that aim to promote ‘disc healing’.

Major Findings: Intervertebral discs deteriorate over many years, from the nucleus outwards, to an extent that is influenced by genetic inheritance, metabolite transport, and mechanical loading. Additionally, surgically-removed ‘painful’ human discs usually show an active inflammatory process proceeding from the outside-in. There is growing evidence that the ligamentous outer annulus can be re-innervated, and sensitized to pain by inflammatory-like responses to injury, and from displaced nucleus pulposus. Animal studies confirm that effective disc healing occurs only in the outer annulus and endplate, where cell density and metabolite transport are greatest. Identifying discogenic pain is not easy, but techniques are available. Healing of the disc periphery has the potential to relieve pain, by reducing inflammation and restoring function.

Conclusion: Physical therapies should aim to promote healing in the disc periphery, by stimulating cells, boosting metabolite transport, discouraging adhesion formation, and preventing re-injury. Such an approach, which can be applied through information sessions and classes, has the potential to bring about pain relief to large numbers of back pain sufferers through self-treatment.

'Healing of painful intervertebral discs: implications for physiotherapy Part 2 — pressure change therapy: a proposed clinical model to stimulate disc healing'

(Key, Adams, Stefanakis)


Background: In Part 1 of this paper, we presented a comprehensive review of the literature, regarding pathophysiology of discogenic pain. Based on the evidence presented, we are suggesting clinical, self-management strategies to promote disc healing and treat disc pain in general.

Objectives: To suggest a physical therapy protocol for self-management of disc injuries and stimulation of disc healing.

Major findings: Inflammatory process after injury to the outer annulus is the most likely source of discogenic pain. Annulus is the tensile load bearing ‘skin’ of the disc and its histology and pathology are similar to other collagen tissues like tendons and ligaments. Conventional physiotherapy wisdom for the management of tendon and ligament injuries is applicant to annular tears. Disc pain without injury is common due to development of stress concentrations in the disc especially during prolonged, end-range postures. Spinal motion segment depends on an optimal disc function. Strategies for management of associated pathologies like apophyseal joint pain and muscle spasm are also considered on this paper.

Conclusion: Physical therapies should aim to promote healing in the disc periphery, by stimulating cells, boosting metabolite transport, discouraging adhesion formation, and preventing re-injury. The self-treatment approach presented in this paper, can potentially provide pain relief to a large number of back pain sufferers. This approach can be applied through information sessions and classes to help deal with the widening back pain pandemic.

You can read it all here in Sarah's best-seller in refreshingly simple layman's language

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