Decompression, Deception and the Magic Machine


It is important to recognize that as we approach nearly twenty years since the initial entrance into the Chiropractic market of Decompression systems, we are still faced with the marketing of magic decompression machines, being somehow different than traction devices based upon mechanisms and pull patterns. For many people, logic, reason and basic physics, though compelling, can’t really compete with marketing hyperbole and the longed for wish of magic stuff.  It is funny how at least 45% of PTs use TRACTION machines (NOT decompression systems)(Hartte et al 2005) for disc and nerve encroachment syndromes and NONE to my knowledge has EVER encountered proprioceptive “lockdown”.  Let’s not forget the thousands of chiropractors who utilize inexpensive traction/decompression who are somehow managing to get the same if not better results as well.

Just recently I was perusing You tube and came across a thirty minute segment by an Osteopath extolling the incredible (and not surprisingly fully exaggerated) benefits of a decompression treatment on his $90,000 system. Also not surprising would be the fact that this doctor was a contracted speaker (perhaps more accurately described as a shill) for this particular company. He blended pseudo-science/marketing jargon to expertly give the gullible listeners the idea that muscles “spasm/guard” reflexively when ordinary traction is applied to the spine. However, with the apparently magic attributes of his system, no such detriment is encountered and, magically, decompression can occur…. The main problem of course is that neither the creator or evolution put “reflexive muscle guarding” mechanisms into our spines when they are stretched. Reason might lead one to recognize that if, in fact, your back muscles “seized up” upon axial stretch, you’d immediately become hyper-extended!  I might refer anyone who thinks that the body has some reflexive guarding mechanism to Bogduk, Adams, et al, Biomechanics of the Spine 2006.  The chapter on spinal “distraction” should be enlightening in this regard: … “neither the human skeletal structures or the central nervous system has created any real guards against [traction]….certainly NO para-spinal, global muscle interface creating “lockdown”.
Many authors and manufacturers in pursuit of the “magic machine theory” continue to completely mis-interpret (either purposefully or through ignorance) Nachemson’s initial study done in 1983. It is vitally important to set the record straight on this one (for the 1000X) as I have tried to for 11 years now…  Nachemson used passive and active traction (auto-traction/Lind method where the patient uses their arms and legs to pull themselves with a pelvic harness applied) and concluded: that axial, passive traction, DID NOT increase disc pressure. A normal inspiratory/expiratory fluctuation was noted BUT para-spinal muscles DID NOT contract. Onel in Spine 1989 “tractioned” (with a TRACTION machine) 39 patients in a CT scanner and found negative pressure (centripetal effect) occurred. Gay, et al, in 2007 also found consistent negative IDP with traction application. His conclusion is that traction predictably lowers intradiscal pressure and IT is the health of the disc…it’s inherent ability to absorb fluid which creates “decompression” NOT a machine attribute. We must dispense with the fictitious & factitious “muscle guarding” phenomena….it only hurts us all as a profession. I might also call attention to Dr. Nachemsons’ letter to the editor JNeuroSurg 1995 after the Ramos & Martin VAX-D study. Martin agreed with Nachemson that passive traction DOES NOT cause muscle contraction or increase disc pressures.
When salesmen practice hyperbole in regards to their products, it is one thing. It is an entirely other problem when respectable doctors perpetuate what can only be seen as junk science in the name of deceptive trade practices. Some concepts in the practice of medicine/chiropractic should be relatively easy to recognize, namely there are no magic low back machines with a magic time/force pull-pattern, nor can you target a specific disc which, in a heterogeneous population, is a bio-mechanical impossibility.  
There have been few products that have engaged and perhaps intrigued chiropractic like decompression. In fact, it wouldn’t be too far from the truth to suggest it may be the most expensive and costly product line ever to be foisted on us as a profession. The initial entrance price was at least $125,000. This has modified to between $49,000 to $95,000 in the last years (these are machines specifically perpetuating the Decompression moniker and attributes as distinct from basic pelvic traction). A notable purveyor of decompression machines has had lawsuits filed by their customers against them for making equipment sales based upon unsupportable claims in their marketing. On at least two instances, State Boards have warned Chiropractors against making scientifically unsupportable claims and there have also been consumer protection prosecutions against individual practitioners for making these claims as well. Fortunately for our profession, knowledge evolves over time. Unfortunately for those caught in the marketing maelstrom, they may have lost goodly chunks of their retirements and kid’s college funds in the pursuit of the magic machine.
It is important to recognize that decompression is always an outcome of axial traction, dependant not on magic machine attributes or some equally specious decompression pull pattern, but on the health of the disc i.e. its fluid properties, and directional preference positioning.
Having taught decompression seminars to thousands of diverse clinicians for nearly a decade, I am convinced of the efficacy and necessity of axial traction in a Chiropractic clinic. Our use of the term Decompression is purely as an outcome of applied axial traction on an intact disc, not as a hyperbolic, fictitious attribute created by the machine or pull pattern choice. Interestingly almost twenty-five years ago the world renowned  PT Gregory Grieves said: “don’t be too beguiled by fancy knobs, chrome or electronic contrivances…these often confuse the therapist into believing the machine, not the user is responsible for the outcome”. This was 25 years ago, yet today we still see reputable doctors suggesting $40-100,000 is necessary to assure a disc can be “decompressed”. We also see huge corporations training their dealers to convince doctors that there are magic pull patterns responsible for the creation of disc decompression. We see manufacturers developing “new” systems and contrivances with virtually NO input from stationed research or experienced clinicians. A decade ago, I started to suggest we should all step back and take a deep breath and recognize that real science excludes magic machines. I love magic…but I hate it when a magician pretends that isn’t what they’re doing. When it comes to decompression, the choice is clear…it’s either science or it’s deception.



Dr. Jay Kennedy is a graduate of Palmer College and has been in both private and MD/DC practices in Berlin, PA, for over 23 years. He is a leading authority in North America on decompression and rehabilitation procedures and has successfully treated tens of thousands of patients. He has pioneered decompression therapy technique since 1993.  Dr. Kennedy is also a renowned product designer and holds multiple patents.  Dr. Kennedy is a frequent guest lecturer at leading chiropractic colleges and decompression therapy certification seminars throughout the US. For more information, email Dr. Jay Kennedy [email protected].


  1. Biomechanics of back pain. Adams M, Bogduk, N et al. Churchill Livingstone 2006.
  2. Clinical anatomy of the lumbar spine.  Bogduk & Twomey. Churchill Livingstone 1991
  3. Fritz et al; Is there a subgroup of patients with LBP likely to benefit from traction? Spine (32) 2007.
  4. Harte AA et at; Current use of lumbar traction in the mangt of LBP. Arch Phys Med Rehab 2005.
  5. Andersson GB, Nachemson AL; IVD pressures during traction. Scand J Rehab 1983.
  6. Gay RE et al; Stress in lumbar IVD during distraction: a cadaveric study. Spine Nov-Dec. 2008.
  7. Onel et al; CT investigation of the effect of traction on lumbar herniation. Spine 1989.
  8. Ramos G, Martin W; effects of VAX on IVP. JNeurosurg 1994.
  9. Cai et al; A clinical prediction rule for classifying patients with LBP who demonstrate short-term improvement with traction. Eur Spine 2009.
  10. Nechemson Al; Neurosurgical forum/letters to the editor. JNeurosurg 1995.
  11. Class action complaint. Tony L. Hoang, Charles C. Strong v. Axiom Worldwide et al. Alameda County Superior Court. Case No. RG07347405, filed Sept 21, 2007. 
  12. Logsdon L. Letter to [a KY D.C.], Nov 6, 2009. The Kentucky Board of Chiropractic Examiners ordered [a KY D.C.], to cease-and-desist making unsubstantiated statements that decompression is more effective than other forms of traction.
  13. Watsonville chiropractor held liable for deceptive ads. Santa Cruz Sentinel, Dec 7, 2006.

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