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Spinal manipulation biochemical

Biochemical Markers of Pain Perception and Stress Response Following Spinal Manipulation

Spinal manipulation biochemicalSpinal manipulation (SM) can improve function and reduce spinal disability.  SM also provides pain relief for many disorders such as back pain and neck pain.   Pain induces changes in both the central and peripheral nervous systems.  The mechanisms by which SM alters musculoskeletal pain are still not completely known.  Current evidence however suggests that SM is associated with neurophysiological responses including rapid hypoalgesia with simultaneous sympathetic and motor system excitation.  Animal studies have shown that analgesia provided by joint mobilization involves serotonin and noradrenaline receptors in the spinal cord.

A new investigation sought to determine the response of several other biochemical markers of pain and stress to SM.  Specifically, three neuropeptides (neurotensin, oxytocin, orexin A) and a glucorticoid hormone (cortisol) were studied.  The authors note that the neuropeptides have been associated with hypoalgesia and pain modulation and that cortisol plays an analgesic role in the stress response.  Recent theories have suggested that chronic pain could be partially maintained in a facilitated state due to maladaptive responses in the presence of recurrent stressful situations.  To date there is a lack of studies analyzing these specific biomarkers in relation to SM.

The purpose of this study was to determine the effect of cervical or thoracic manipulation on neurotensin (NT), oxytocin, orexin A, and cortisol levels.  Experimenters examined both spinal regions because they thought there may be a difference in anti-nociceptive effect between the cervical spine and thoracic spine.

Participants included graduate students from Spain.  All subjects were asymptomatic and were excluded if there was a contraindication to manipulation, history of whiplash or surgery, pain in the last month, SM in the last 2 months.  Thirty asymptomatic subjects were randomly divided into 3 groups: cervical manipulation (n = 10), thoracic manipulation (n = 10), and non-manipulation (control) (n = 10).  Although it is not explicitly stated in the article, I presume the manipulations were performed by physical therapists since the lead authors were PT’s.  Manipulations consisted of supine ‘anterior’ thoracic spine manipulations, and rotary type cervical manipulations.  Blood samples were extracted before, immediately after, and 2 hours after each intervention by way of venipuncture of the cephalic vein. Neurotensin, oxytocin, and orexin A were determined in plasma using enzyme-linked immuno assay. Cortisol was measured by microparticulate enzyme immuno assay in serum samples.

Results

Neurotensin (NT)

  • Statistically significant increases in neurotensin occurred in both the thoracic and cervical manipulation groups compared to controls post-intervention with the greatest increase occurring immediately following manipulation
  • Cervical spine manipulation produced a slightly larger increase in neurotensin

Orexin A

  • No statistically significant changes were noted in orexin A levels following treatment

Oxytocin

  • Statistically significant increases in oxytocin occurred in both the thoracic and cervical manipulation groups compared to controls post-intervention with the greatest increase occurring immediately following manipulation
  • Cervical spine manipulation produced a significantly larger increase in oxytocin compared to thoracic manipulation

Cortisol

  • A significant increase in cortisol occurred in the cervical manipulation group compared to controls and the thoracic manipulation group immediately post-intervention
  • However, a significant decrease in cortisol was found at 2 hrs post intervention in the thoracic SM group compared with pre-intervention values
  • A non-significant decrease in cortisol was found also found at 2 hrs post intervention in the cervical SM group compared with pre-intervention values


Discussion

NT is an endogenous peptide with broad spectrum of central and peripheral activities, including modulation of pain signal transmission and perception. NT behaves as a neurotransmitter in the brain and as a hormone in the gut.  Because of its association with a wide variety of neurotransmitters, NT has been implicated in the pathophysiology of several CNS disorders such as schizophrenia, drug abuse, Parkinson’s disease (PD), pain, central control of blood pressure, eating disorders, as well as, cancer and inflammation. Note that the antinociceptive effects of NT are independent from opioid antinociception.

Increased oxytocin following SM could be partly responsible for the analgesic effect linked to manual therapy techniques due to the activation of descending pain-inhibitory pathways.

Cortisol is a potent anti-inflammatory that functions to mobilize glucose reserves for energy and modulate inflammation. Ultimately, a prolonged or exaggerated stress response may perpetuate cortisol dysfunction, widespread inflammation, and pain.  SM in this study led to an immediate increase in cortisol followed by a significant 2 hour decrease in levels with thoracic manipulation and a decrease in 2 hr levels with cervical manipulation.


Key Points

  • SM can modify several biochemical markers of pain and stress
  • These findings suggest that descending inhibitory pathway mechanisms may be involved in the physiological effects that follow SM
  • The effect size for the cervical manipulation group was larger than that for the thoracic manipulation group suggesting an increase in the activation of the possible descending inhibitory pathway mechanisms after cervical manipulation compared to thoracic manipulation

Reference: Plaza-Manzano G, Molina-Ortega F, Lomas-Vega R, Martínez-Amat A, Achalandabaso A, Hita-Contreras F. Changes in biochemical markers of pain perception and stress response after spinal manipulation. J Orthop Sports Phys Ther. 2014 Apr;44(4):231-9.

Chiropractic and Immediate Pain Relief

18448850_xxlThe application of spinal manipulative therapy (SMT) is a cost-effective and widely recognized manual intervention used by a variety of health care professionals in the management of musculoskeletal pain. A growing body of scientific evidence supports the use of SMT for the treatment of a broad range of musculoskeletal disorders citing short-term antinociceptive (pain-relieving) effects and restoration of normal joint mechanics.

Last year, about this time, I wrote about a systematic review that found spinal manipulation therapy (SMT) has a pain reducing effect as measured by pressure pain thresholds (PPT).  Additionally, the effect of SMT on pain reduction was statistically significant at remote locations (for example, adjusting the neck yielded reduction in pain at the elbow).

A new study has emerged in the scientific literature that advances our understanding of the topic (Srbely et al, 2013).  The authors note that although the pathophysiology of myofascial pain syndrome (MPS) is still unclear, research suggests that myofascial trigger points (MTPs) play an fundamental role in the generation and clinical manifestation of MPS.  However, it is currently unknown if the antinociceptive effects of SMT in myofascial tissues are manifest predominantly via regional or general mechanisms, or a combination of both. A study was needed to specifically investigate the hypothesis that SMT evokes robust antinociceptive effects in MTPs preferentially located within neurosegmentally linked myofascial tissues.

Srbely et al conducted the study through the University of Guelph.  The study was a single session, single blinded, randomized controlled intervention.  The primary inclusion criterion was the presence of a clinically identifiable MTP locus (active or latent) within the right infraspinatus and right gluteus medius muscles.  The primary diagnostic criterion used to clinically identify the trigger point locus was ‘a palpable hyperirritable nodule nested within a taut band of skeletal muscle; sustained ischemic pressure over the trigger point locus elicited a dull achy regional pain or discomfort.’  Exclusion criteria encompassed conditions that would affect normal somatosensory processing.

Thirty-six participants qualified for the study and were randomly assigned to test or control groups.  Two chiropractors saw participants at an urban outpatient clinic. One chiropractor performed the history, exam and manipulations while the other chiropractor (blinded to treatment allocation) detected the trigger points and measured all PPTs. The primary outcome was PPT values from infraspinatus and gluteus medius muscles.  The infraspinatus was chosen due to its innervation from the manipulated segment (C5-6). The gluteus medius acted as a regional control point (L4-S1 innervation).

PPT was measured with a force gauge (Newtons) over the trigger point locus (infraspinatus, gluteus medius) and was defined as the force necessary to elicit the onset of a deep dull achy local discomfort and/or referred pain. Measurements were taken at 1,5, 10, and 15 minutes postintervention.  In order to specifically compare regional antinociceptive effects between intervention groups, the authors also calculated the PPT difference (PPTdiff) between infraspinatus and gluteus medius trigger points at each time interval within each participant. Participants received a rotary type manipulation to the C5-6 segment in a supine posture.   Additionally, a drop piece mechanism was used to aid in the high velocity low amplitude thrust.  Control participants received a sham manipulation.  The sham consisted of rotating the neck of the participant, supporting the neck of the participant with the clinician’s forearm under the headpiece and a thrust of the forearm into the headpiece.  It is noted that the contact hand did not thrust and did not create ‘a real manipulation’ of any segment.

Results:

  • there was a significantly increased PPT threshold for infraspinatus trigger points in treated participants compared to controls at all time intervals beyond baseline
  • there was a significantly increased PPT threshold for infraspinatus compared to gluteus medius before and after manipulation at all time intervals beyond baseline
  • no significant differences in PPT scores were observed at any time interval when comparing test gluteus medius, control infraspinatus, and control gluteus medius groups
  • there were significant increases in PPTdiff in the test group vs controls at all time intervals beyond baseline

Key Findings:

  • This study suggests that SMT evokes statistically significant short-term increases in PPT in segmentally related myofascial tissues in young adults
  • Decreased pressure sensitivity (increased PPT score) was observed at all time intervals beyond baseline within neurologically linked infraspinatus muscle after real, but not sham, manipulation
  • The peak antinociceptive effect was measured as a 36% decrease in pressure sensitivity from baseline values and was recorded at 5 minutes postSMT

So, what does this study tell us?  It suggests that SMT evokes robust regional antinociceptive effects in myofascial tissues.  It also provides important evidence to support further research into the potential benefit and role of SMT in the management of chronic widespread pain syndromes  including myofascial pain, and fibromyalgia.

Reference: Srbely JZ, Vernon H, Lee D, Polgar M. Immediate effects of spinal manipulative therapy on regional antinociceptive effects in myofascial tissues in healthy young adults. J Manipulative Physiol Ther. 2013 Jul-Aug;36(6):333-41.

 

Chiropractic Manipulation Versus Usual Medical Care for Acute and Subacute Low Back Pain

33609004_sLow back pain (LBP) is an extremely common presenting complaint that occurs in greater than 80% of people. Chiropractors care for patients who have no symptoms and those who have symptoms.   Research has demonstrated that chiropractic care in addition to standard medical care improves pain and disability scores, and in another study a subgroup of patients with acute nonspecific LBP – spinal manipulation was significantly better than nonsteroidal anti-inflammatory drug diclofenac and clinically superior to placebo (Spine 2013; 38:540-548).  The study reviewed here sought to compare the effectiveness of manual thrust manipulation (MTM) and manual assisted manipulation (MAM), to usual medical care (UMC) for the treatment of acute and subacute LBP.

This study was a prospective, randomized controlled trial evaluating the comparative effectiveness of manual and mechanical spinal manipulation to usual medical care for the treatment of acute and subacute LBP.  Participants were at least 18 years old and had a new LBP episode within the previous 3 months.  They also were required to have a minimum level of self-rated pain of 3 out of 10 and minimum disability rating of 20 out of 100. Exclusions included: chronic LBP (greater than 3 months duration), previous treatment for the current episode, radicular signs/symptoms, contraindications to SMT, current use of prescription pain medicine.

Participants and treating clinicians were not blinded to treatment allocation but the principal investigator was blinded to treatment assignment and had no interaction with participants.

The study interventions consisted of:

  1. Manual thrust manipulation (MTM) – high velocity low amplitude thrust delivered by a chiropractor to the lower thoracic, lumbar and SI joints in the side posture position as deemed necessary
  1. Mechanical-assisted manipulation (MAM) – certified Activator Methods chiropractor delivered MAM in the prone position to the lower thoracic, lumbar and SI joints as deemed necessary
  1. Usual medical care (UMC) – participants were seen by a board certified physical medicine and rehabilitation medical doctor and prescribed over the counter analgesic and NSAID medications, given advice to stay active and avoid bed rest

All groups had a 4 week course of care.  All groups received an educational booklet describing proper posture and movements during activities of daily living. Both manipulation groups had 8 visits (2 per week x 4 wks).  The UMC group had 3 visits (initial, at 2 weeks and at 4 weeks).  Following the 4 week assessment, participants were free to pursue rehabilitation or manipulation.

The primary outcome was the Oswestry LBP Disability Index (OSW).  Pain intensity ratings were also collected. Outcomes were assessed at baseline, 4 weeks, 3 months and 6 months.  Participants with at least 30% or 50% reductions in an outcome measure were considered to be ‘responders’ and had moderate or substantial improvement respectively.

Results and Conclusions:

  • Manual thrust manipulation by a chiropractor led to greater short term reductions in self-reported pain and disability than manual assisted manipulation (Activator) or usual medical care by a physical medicine and rehabilitation specialist
  • The benefits seen at the end of 4 weeks of care were no longer statistically significant at 3 or 6 months
  • MTM should be considered as an effective short term treatment option for patients with acute and subacute LBP
  • Significantly more patients in the MTM group achieved moderate or substantial reductions in disability and pain scores
  • These results contradict assumptions of therapeutic similarity between manual thrust and mechanical-assisted manipulation

Reference: Schneider M, Haas M, Glick R, Stevans J, Landsittel D. Comparison of spinal manipulation methods and usual medical care for acute and subacute low back pain: a randomized clinical trial. Spine (Phila Pa 1976). 2015 Feb 15;40(4):209-17.

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Risk of Injury Following Visits to Health Professionals

Aging ChiropracticThere are physiologic changes associated with aging. There are also health conditions that occur more commonly with advancing age. These changes and conditions increase an older adult’s vulnerability to injuries. A recent study investigated risk of injury to Medicare beneficiaries with an office visit for a neuromusculoskeletal problem to chiropractors and primary care physicians.  Specifically, investigators looked at the risk of injury within 7 days of those treated by chiropractic spinal manipulation vs. those evaluated by a primary care physician.  Results showed that risk of injury to the head, neck or trunk within 7 days was 76% lower among subjects with a chiropractic office visit as compared to those who saw a primary care physician.

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Chiropractic Has Lowest Total Costs for Low Back Problems in a Major Self-Insured Workforce

Low Back PainStatistics tell us that up to 84% of the general population will report low back pain (LBP) symptoms at some point during their lifetime.  This leads employers seeking to maximize the ratio of outcomes achieved relative to costs incurred (ie, value) for the investments that they are making in their employees. Previous research has found that patients receiving chiropractic care have been found to record lower associations of probability of disability recurrence than patients of physicians and physical therapists.  Given these findings, the authors of this newly published article sought to assess the cost outcomes of treatment approaches to care for back problems in a major self-insured workforce, using published guidelines to focus on low back pain. Results of the study were that care congruent with 10 of 11 guidelines was linked to lower total costs. Of the five patterns of care, complex medical management reported the highest guideline-incongruent use of imaging, surgeries, and medications and had the highest health care costs.  On the other hand, chiropractic reported the lowest rates of guideline-incongruent use of imaging, surgeries, and medications and had the lowest health care costs.

http://www.ncbi.nlm.nih.gov/pubmed/24854253

Podcast

018- Chiropractic Dose-Response Relationship and Public Health with Dr. Mitch Haas

dr-mitch-haasDr. Mitch Haas and I discuss the dose-response relationship between chiropractic and health outcomes as well as chiropractors in public health. Dr. Haas has been an integral member of the research division at the University of Western States (UWS) since joining the faculty in 1987. He is now the associate vice president of research at UWS. Dr. Haas also serves as an adjunct associate professor in the neurology department at Oregon Health & Science University (OHSU). Dr. Haas has been either principal investigator or co-investigator on more than 30 extramurally funded grants bringing more than $7 million in research funding to UWS. In 1994, he was a co-investigator on the first federal research grant ever awarded to a chiropractic college.

Dr. Haas has since become the principal investigator (PI) for a number of large federal grants awarded by the U.S. Department of Health and Human Services (U.S.D.H.H.S.) Health and Resources Services Administration and the National Center for Complementary and Alternative Medicine at the National Institutes of Health. These collaborative projects with OHSU and other institutions were designed to evaluate pain and disability outcomes and cost-effectiveness of chiropractic and medical treatment for low back pain, a chronic pain self-management program in the elderly, the relationship of the number of chiropractic treatments with health outcomes for low back pain and headaches and care of low back pain in adolescents.

Dr. Haas has been active in state and national public health associations. He was the founding chair of the Chiropractic Healthcare Section of the American Public Health Association (APHA) and has since served as chair of the APHA Intersection Council, a governing councilor, member of the APHA Executive Board and chair of the APHA Bylaws Committee. He was also the 2007 president of the Oregon Public Health Association (OPHA).

Check out Dr. Mitch Haas’s publications on researchgate.

Here are the articles we discuss in this podcast episode:

1. Dose-response of spinal manipulation for cervicogenic headache: study protocol for a randomized controlled trial.
Hanson L, Haas M, Bronfort G, Vavrek D, Schulz C, Leininger B, Evans R, Takaki L, Neradilek M.
Chiropr Man Therap. 2016 Jun 8;24:23. doi: 10.1186/s12998-016-0105-z.
PMID: 27280016 [PubMed] Free PMC Article
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2. Dose-response and efficacy of spinal manipulation for care of chronic low back pain: a randomized controlled trial.
Haas M, Vavrek D, Peterson D, Polissar N, Neradilek MB.
Spine J. 2014 Jul 1;14(7):1106-16. doi: 10.1016/j.spinee.2013.07.468.
PMID: 24139233 [PubMed – indexed for MEDLINE] Free PMC Article
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3. Cost analysis related to dose-response of spinal manipulative therapy for chronic low back pain: outcomes from a randomized controlled trial.
Vavrek DA, Sharma R, Haas M.
J Manipulative Physiol Ther. 2014 Jun;37(5):300-11. doi: 10.1016/j.jmpt.2014.03.002.
PMID: 24928639 [PubMed – indexed for MEDLINE] Free PMC Article
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4. A path analysis of the effects of the doctor-patient encounter and expectancy in an open-label randomized trial of spinal manipulation for the care of low back pain.
Haas M, Vavrek D, Neradilek MB, Polissar N.
BMC Complement Altern Med. 2014 Jan 13;14:16. doi: 10.1186/1472-6882-14-16.
PMID: 24410959 [PubMed – indexed for MEDLINE] Free PMC Article
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