037- The Science of Lumbar Adjustments
11 Nov 2025 · 0 min
Podcast episode (host: Dr. Jeff Langmaid) reviewing a 2002 Spine Journal study titled 'Effects of Side Posture Positioning and Spinal Adjusting on the Lumbar Z Joints.' The host explains that chiropractic lumbar adjustments (particularly when performed and held in side-posture) produced measurable gapping of lumbar facet (Z) joints — reported as over 2 mm (approaching 3 mm) in the adjustment+side-posture group versus under ~0.3 mm in control groups — and discusses clinical implications (adhesion release, increased ROM, reduced pain, CNS effects). Episode also includes sponsor mention (RockTape) and event promotion (California Chiropractic Association).
Questions this episode answers
2002
Greater than 2 millimeters (described as approaching 3 mm)
Less than approximately 0.3 millimeters ("less than 3/10 of a single millimeter" as stated verbally)
Welcome to the Evidence Based Chiropractor. Providing you with elegant and efficient research based content to help your practice prosper and succeed. Now get ready for a variety of dynamic communication tools designed for immediate growth. Courtesy of your host, Dr. Jeff Langmaid.
Hello and welcome to the Evidence Based Chiropractor. This week's podcast is a very special one. We are doing it up big here today. This is the first week we're going straight to video. So we're gonna have audio version of our podcast, we're gonna have a video version of our podcast and we actually have a third camera going on Facebook live here currently right now. So it's an exciting podcast due to new features and also due to today's content. Today we have another deep cut on the research front where we're gonna look at a piece of research that came out of Spine Journal and it was released in 2002. So it's not the newest piece of research, but it's an extremely important piece of research. And with that, this piece looked at the effects of side posture, positioning and spinal adjusting on the lumbar Z joints. So as we know in chiropractic, the adjustment, the chiropractic manipulation, the hallmark of what we do week in and week out. And this paper looks at how that affects the lumbar spine and specifically the gapping of the Z joints or the facet joints. So as we get started, we will say a few words about Roc Tape as we do each and every week. Roc Tape is proud to be a sponsor of the evidence based chiropractor. Rocktape offers the world's best kinesiology tape, pain relief, topicals, mobility tools and functional fitness accessories. New from Rock Tape is Rocksauce Chill, Powerfully cool pain relief topical and a convenient roll on with 6% menthol. You know it is stronger than the freeze competition. Learn more and get access to your medical discount at Rock Tape. They are more than a tape company, they are a movement company. And if you didn't check out our interview with Dr. Steve, Medical Director at Rocktape a couple weeks back, please, please do so. Him and I also are gonna be speaking at the sports symposium at the California Chiropractic association event this coming week. So we are in the countdown stages for that event. A fantastic array of speakers. I know both Dr. Steve and I chatted about it on the podcast here, but we are thrilled to be a part of it. So check that out at California Chiropractic association. It is at Disney. It's gonna be super cool. And if you head out there, hit me up because I'm gonna to meet up, chat and kind of take it from there. So without further ado, today's topic spine journal 2002 the effects of side posture, positioning and spinal adjusting on the lumbar Z Joints. So chiropractors we know painful, arthritic and degenerative facet joints, also known as Z joints, are a common problem for patients with a sedentary, inactive lifestyle, which may be a few of your patients. This is exacerbated by the posterior migration of the instantaneous axis of rotation as we age. What that means, of course, is when we are young, our discs are supple and they move from directly the center point or the centerpiece of that intervertebral disc. But as time goes on, as we age, the load transfers disproportionately to the facet joint and that axis of rotation migrates posteriorly. Medication Sometimes RFAs, radiofrequency ablations are frequently used for treatment. However, as we'll learn today, research continues to clearly support the use of chiropractic care for these patients. Chiropractic adjustments in this paper were shown to significantly gap the facet joints. Gapping of the facet joints can release adhesions and and alter the pain sensitivity threshold of the nerve fibers in those facet joints. Additionally, it stimulates a muscle spindle stretch response and it impacts the central nervous system. So within chiropractic, we are always talking about impacting the central nervous system. One of the best ways to go about doing that is by getting in there and gapping that Z joint or gapping that facet joint decreases pain not only local to the facet, but it can also decrease pain system wide. Based on that impact with the central nervous system, there are a few proposed mechanisms by which the chiropractic adjustment can decrease pain and increase functional status. And a lot of that dives straight back to that chiropractic adjustment, that chiropractic manipulation and the stimulation that it provides through our nervous system that can start in, believe it or not, in the facet joint itself with the gapping and increasing that threshold. So there's a few quotes on this paper that I think are extremely hard hitting that we'll talk about. And they are. The researchers found hypomobility may be the result of injury inactivity or repetitive asymmetrical movements. We know that movement decreases over time because of the cumulative effects of injury and activity. And again, repetitive asymmetrical movements. Our bodies are meant to move in a certain fashion, and that is with the least amount of stress. Stress is good to a certain degree, but consistent repetitive motion as weeks become months, become years become decades, can be extremely challenging on our bodies. Secondly, they found gapping breaks up adhesions, thus helping the motion segment re establish a physiological range of motion. So gapping those facet joints can break up any inter articular adhesions and help the mobility of that joint throughout time and have a better overall range of motion. With a better overall range of motion, that's gonna enable a patient to move better and certainly to feel better, especially when you get on it with that stimulation to the central nervous system and that increased threshold for sensitivity. The researchers also found quote they found significant differences between several groups in this study with the group that received chiropractic adjustments and and remained in the side posture positioning showing the greatest increase in gapping. This finding is consistent with the hypothesis that chiropractic adjusting gaps the Z joints. So they looked at patients who got into a side lying position, received that lumbar adjustment and stayed in that position for them to of course, take their pictures and analyze that gapping. And they found unequivocally, compared to control groups, those Z joints stayed farther gapped for the patients that received that adjustment. So there was direct impact there. There's one other quote that I'll touch on here for this study and that is quote, the authors believe that these differences in gapping are not only significant, but that they also may be clinically relevant. And that gets to the heart of what we're talking about today, which is the fact that when you get into a side lying position, a chiropractic adjustment is given in that signed lying position and the central nervous system is affected, adhesions are released and there's a greater increase in range of motion. It can result in higher function for that patient and absolutely decreased pain. So that is the clinically relevant portion of it. And when the researchers looked through this, they looked at a few different groups of people. Number one is they looked at a group that just laid in a side posture position. So nothing else but lying in a side posture position. That was group one measurements. And all group two was an adjustment and then a neutral position. So patient received adjustment, went back to neutral, pre and post pictures taken, group three adjustment, then side posture. So the patient received that adjustment and then stayed not for a long time, but enough to get those images or that evaluation done in that side lying position. In group four was control neutral, neutral. So just straight up Neutral positions, gapping in the millimeters on those facet joints, Nothing approached more than 2 millimeters except for the adjustment then side posture, and that was well over 2 millimeters on its way to 3 millimeters, the natural state, I guess, to put that into perspective, in your control group, it was less than 310 of a single millimeter. So that's a wide gap in terms of, no pun intended, in terms of how truly wide or the distance that was created in those Z joints during and after, most importantly, that chiropractic manipulation or that chiropractic adjustment. So each and every week I know we talk about this, but it's really. This is an interesting piece because again, I'll repeat the title of it and you'll find it in the show notes on this podcast as well for a direct citation to PubMed. But this was released by Spine Journal, Top Tier research journal in 2002 and the title was the Effects of Side Posture Positioning and Spinal Adjusting on the Lumbar Z Joints. So I love this study because it really gets to the clinical nature of what we do as chiropractors. It's not so much in the vein of theoretical, but it's true. Hard data and hard facts regarding what a patient experiences or what they go through when they receive a chiropractic adjustment. In our office we featured this in December 2015 for all of our members. So this was a past research brief and it was something that I know built a lot of credibility, a lot of trust, and really put out a lot of interesting information through this paper for our members who dispersed it to their medical doctors in their communities. Because a lot of times the true nature of the chiropractic adjustment, you know, there's a lot of myth and conjecture regarding that. And when we have a paper from Spine Journal, a Top Tier Research piece, that shows the gapping of the Z joints, that emphasizes the fact that the chiropractic adjustment stimulates that and also touches on the potential clinical relevancy of that. I think it really fires on all cylinders. So I love this piece of research for those reasons. Amongst a few others, you can find a direct citation to this. You can in our show notes as well. We did a few tweaks to the website this past week. So if you haven't been on the website in a while, the evidencebasedchiropractor.com, i recommend you check it out. There are free tools there. There is of course, our monthly membership, which is kind of the hallmark of what we do. Helping chiropractors worldwide build those referral relationships. There are links to various content. We're above 30 podcast episodes, so you can't go wrong. I guarantee you can get some piece of actionable content if you visit theevidencebasedchiropractor.com, and if you do, if you see anything you like, you have any questions, reach out to me directly. Jeffevidencebasedchiropractor.com Next week I will be actually in California, so I'm gonna speak with Paul who's been helping me do some of this video and podcasting. We're gonna figure out exactly how we wanna go about things for next week. We will be back with a podcast next week, but I will also be out in California. Chiropractic California Chiropractic association with Steve at Rocktape. So looking forward to it all, doc. Have a fantastic week in practice and I'll talk to you soon.
We appreciate you joining us for this episode of the Evidence Based Chiropractor. Learn more tips for explosive practice development@the evidencebasedchiropractor.com youm can also join the Premier MD monthly membership, enabling you to use what you just heard to maximize results in your office. We look forward to providing you with more dynamic communication tools for immediate growth right here on the Evidence Based Chiropractor.
Sam.
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