Chiropractic Spinal Manipulation Research Articles

Strain of the vertebral artery during passive neck movements and spinal manipulation of the cervical spine: An observational study

BackgroundNeck pain is a common condition, and a frequent treatment is chiropractic cervical spinal manipulation therapy (cSMT). However, cervical spinal manipulations have been associated with excessive cervical artery elongations, allegedly causing arterial dissection leading to stroke. PurposeThe primary purpose of this study was to quantify the total vertebral artery elongations during cSMT, and secondarily, quantify the vertebral artery elongations during the pre-manipulative orientation of the head and neck and the subsequent elongations during the actual thrust. MethodsVertebral artery strains were measured at the cervical levels C0–C1, C1–C2, and C2–C3 using piezoelectric crystals that were sutured to the wall of the left and right vertebral artery in three cadavers. Vertebral artery strains were measured continuously for a full set of passive range of motion testing and for the chiropractic spinal manipulation. FindingsFor the range of motion testing, the greatest average vertebral artery strains at the C0–C1 level were 6.9% for ipsilateral flexion-rotation, at the C1–C2 level 4.3% for contralateral rotation, and at the C2–C3 level 3.7% for contralateral flexion-rotation. For the chiropractic spinal manipulation, the average maximal strains at the C0–C1, C1–C2 and C2–C3 levels were 1.3%, 0.1%, and 1.0%, respectively. The maximal average vertebral artery strains in the pre-manipulative phase were 0.5% and the corresponding maximal vertebral artery strains during the manipulative thrust was 1.1%. InterpretationPassive range of motion testing produced strains in the vertebral artery were 5.3 times (C0–C1), 7.2 times (C1–C2), and 3.7 times (C2–C3) greater than the corresponding strains during chiropractic spinal manipulation, suggesting that strains in the vertebral artery during chiropractic spinal manipulation were much smaller than the strains that can occur during normal everyday movements of the head and neck. Furthermore, vertebral artery strains in the pre-manipulative phase did not contribute to the peak strains on the contralateral vertebral artery and helped reduce strains on the ipsilateral side.

Chiropractic spinal manipulation and likelihood of tramadol prescription in adults with radicular low back pain: a retrospective cohort study using US data

ObjectivesPatients receiving chiropractic spinal manipulation (CSM) for low back pain (LBP) are less likely to receive any opioid prescription for subsequent pain management. However, the likelihood of specifically being prescribed...

Association between chiropractic spinal manipulation and cauda equina syndrome in adults with low back pain: Retrospective cohort study of US academic health centers.

Cauda equina syndrome (CES) is a lumbosacral surgical emergency that has been associated with chiropractic spinal manipulation (CSM) in case reports. However, identifying if there is a potential causal effect is complicated by the heightened incidence of CES among those with low back pain (LBP). The study hypothesis was that there would be no increase in the risk of CES in adults with LBP following CSM compared to a propensity-matched cohort following physical therapy (PT) evaluation without spinal manipulation over a three-month follow-up period. A query of a United States network (TriNetX, Inc.) was conducted, searching health records of more than 107 million patients attending academic health centers, yielding data ranging from 20 years prior to the search date (July 30, 2023). Patients aged 18 or older with LBP were included, excluding those with pre-existing CES, incontinence, or serious pathology that may cause CES. Patients were divided into two cohorts: (1) LBP patients receiving CSM or (2) LBP patients receiving PT evaluation without spinal manipulation. Propensity score matching controlled for confounding variables associated with CES. 67,220 patients per cohort (mean age 51 years) remained after propensity matching. CES incidence was 0.07% (95% confidence intervals [CI]: 0.05-0.09%) in the CSM cohort compared to 0.11% (95% CI: 0.09-0.14%) in the PT evaluation cohort, yielding a risk ratio and 95% CI of 0.60 (0.42-0.86; p = .0052). Both cohorts showed a higher rate of CES during the first two weeks of follow-up. These findings suggest that CSM is not a risk factor for CES. Considering prior epidemiologic evidence, patients with LBP may have an elevated risk of CES independent of treatment. These findings warrant further corroboration. In the meantime, clinicians should be vigilant to identify LBP patients with CES and promptly refer them for surgical evaluation.

Comparison of the effectiveness of spinal stabilization exercises and chiropractic spinal manipulation in healthy individuals: Randomized controlled trial

Aim: The aim was to investigate the effects of exercise, manipulation and its combined application on endurance, muscle strength, joint position sense and balance. Materials and Methods: Eighty healthy people aged 18-45 years were included in the study. Individuals were divided into chiropractic manipulation, stabilization exercises, combined application and control group. Participants were evaluated with endurance, muscle strength, joint position sense and balance tests before, after and 1 month after the application. Results: After the application, significant improvement was observed in the endurance parameters in Group 3 compared to the other groups. There was a significant increase in quadriceps muscle strength in all groups compared to Group 4. Conclusion: The combined program may be more effective than other programs in improving muscular endurance and balance. All training programs are effective in improving quadriceps muscle strength, but do not have the same effect on knee joint position sense.

Association between chiropractic spinal manipulation and gabapentin prescription in adults with radicular low back pain: retrospective cohort study using US data

ObjectivesRadicular low back pain (rLBP) is often treated off-label with gabapentin or by chiropractors using chiropractic spinal manipulative therapy (CSMT). To date, no studies have examined the association between these...

Patients With a History of Spine Surgery Receiving Chiropractic Spinal Manipulation in US Academic Health Centers: A Cross-Sectional Cohort Study.

The number and characteristics of patients with previous spine surgery receiving chiropractic spinal manipulation (CSM) are largely unknown. This study aimed to explore the proportion of patients receiving CSM with a history of spine surgery, the characteristics of these patients, and the treatments received compared to a broader population of patients receiving CSM. We queried a 110-million-patient United States (US) network of aggregated records and claims data from patients attending integrated academic health centers (TriNetX, Inc.) on March 6, 2023, yielding data spanning 2013-2023. We identified two patient groups: (1) those receiving CSM and (2) a subset receiving CSM with prior spine surgery. We compared baseline characteristics and treatments received over a one-year follow-up after CSM. Of the 81,291 patients receiving CSM, 8,808 (10.8%) had at least one prior spine surgery. Patients with prior spine surgery receiving CSM were older, more often female, more often non-Hispanic/Latino and White, less often Black, had a greater body mass index, and had a higher prevalence of low back and neck pain compared to the broader CSM cohort (p<0.0001 for each). Those with prior spine surgery were also more likely to receive multiple medications, physiotherapy procedures, and spinal injections (p<0.0001 for each). Patients receiving CSM with a history of spine surgery comprise a substantial proportion of CSM patients in large US academic health centers. This subset of patients differs characteristically from the broader CSM population and more often receives medications, physiotherapy, and spinal injections. Further research is needed to examine the safety and efficacy of CSM in this population, given the high proportion of patients and limited research on this topic.

Description of recurrent headaches in 7–14-year-old children: Baseline data from a randomized clinical trial on effectiveness of chiropractic spinal manipulation in children with recurrent headaches

BackgroundHeadaches in children are poorly described and diagnosing can be challenging. Objectives are: (1) to describe headache characteristics and child characteristics, (2) to explore whether data can suggest a more diverse way to categorize headaches than traditionally.MethodsBaseline data for a clinical trial included a questionnaire and a physical screening. Children's characteristics and detailed description of headache symptoms were provided. Children were classified for migraine or tension-type-headache based on questionnaire data reported by children and parents. This required to apply slightly modified classification criteria and a “non-classifiable” group was added. Severity and symptoms, related to the migraine versus tension type distinction, were investigated to define a migraine-tension-type-index.Results253 children were included. Mean pain intensity was 5.9/10. Over 2/3 of the children had headache for > 1 year, and > 50% for several days/week. Half of the children were non-classifiable, 22% were classified as migraine and 23% as tension-type headache. A migraine-tension-type-index was constructed and describes a continuous spectrum rather than two distinct groups.ConclusionsChildren with recurrent headaches are often severely affected. A questionnaire-based classification appeared feasible to distinguish between migraine and tension-type headaches in children but leaving many children unclassified. A migraine-tension-type-index can be generated allowing to regard the traditional distinction as a continuum (including mixed headache), and potentially serving as an instrument to improve headache management.Trial registration ClinicalTrials.gov, identifier NCT02684916.

Comparison of Effectiveness of Chiropractic Spinal Manipulation and Conservative Therapy for Low Back Pain

The study is to describe the current evidence for the effectiveness of chiropractic spinal manipulation in comparison to the conservative intervention on Low Back Pain (LBP). The PubMed database was searched for randomised clinical trials of spinal manipulation and low back pain. Criteria for inclusion was subjects with low back pain treated with chiropractic spinal manipulation. Studies were excluded when participants were under the age of 18; conditions that were considered to be outside the discipline of manual therapy including systemic disease or malignancy, osteoporosis, pathological causes of LBP, LBP with radiculopathy; and contraindications to spinal manipulation. Data extraction included study design, number of participants, gestational age, spinal region, number of manipulations, manipulation technique details, profession of manipulator, active exercise reporting (Yes vs. No), type, and number of active exercises. Chiropractic care seems to be more effective than conservative intervention for LBP in reducing pain, increasing range of motion in lumbar spine, improving disability status, and enhancing general health. Furthermore, integrative care for LBP could be considered to improvise in the future treatment plan. The review of comparing different treatment approaches for LBP is still lacking and future research is needed to consider including a control group in order to provide accurate and persuasive outcomes.

Association between chiropractic spinal manipulation and lumbar discectomy in adults with lumbar disc herniation and radiculopathy: retrospective cohort study using United States’ data

ObjectivesChiropractic spinal manipulative therapy (CSMT) and lumbar discectomy are both used for lumbar disc herniation (LDH) and lumbosacral radiculopathy (LSR); however, limited research has examined the relationship between these therapies....

Absence of Neuroplastic Changes in the Bilateral H-Reflex Amplitude following Spinal Manipulation with Activator IV.

Background and Objectives: Chiropractic spinal manipulation is an alternative medical procedure for treating various spinal dysfunctions. Great interest exists in investigating its neuroplastic effects on the central nervous system. Previous studies have found contradictory results in relation to the neuroplastic changes in the H-reflex amplitude as a response to manual spinal manipulation. The discrepancies could be partly due to differences in the unilateral nature of these recordings and/or the variable force exerted in manual techniques applied by distinct chiropractors. Concerning the latter point, the variability in the performance of manual interventions may bias the determination of the significance of changes in H-reflex responses derived from spinal manipulation. To investigate such responses, a chiropractic device can be used to provide more precise and reproducible results. The current contribution aimed to examine whether spinal manipulation with an Activator IV instrument generates neuroplastic effects on the bilateral H-reflex amplitude in dancers and non-dancers. Materials and Methods: A radiograph verified spinal dysfunction in both groups of participants. Since there were significant differences between groups in the mean Hmax values of the H-reflex amplitude before spinal intervention, an assessment was made of the possible dependence of the effects of spinal manipulation with Activator IV on the basal conditions. Results: Ten sessions of spinal manipulation with Activator IV did not cause statistically significant changes in the bilateral H-reflex amplitude (measured as the Hmax/Mmax ratio) in either group. Furthermore, no significant difference was detected in the effects of spinal manipulation between groups, despite their distinct basal H-reflex amplitude. Conclusions: Regarding the therapeutic benefits of a chiropractic adjustment, herein carried out with Activator IV, the present findings suggest that the mechanism of action is not on the monosynaptic H-reflex pathway. Further research is needed to understand the mechanisms involved.

Concurrent Bell’s Palsy and Facial Pain Improving with Multimodal Chiropractic Therapy: A Case Report and Literature Review

Patient: Female, 52-year-old Final Diagnosis: Bell’s palsy • trigeminal neuropathy Symptoms: Facial pain • facial paresis • neck pain Medication: — Clinical Procedure: Cervical traction • exercises • soft tissue manipulation • spinal manipulation Specialty: Neurology • Rehabilitation • Traditional Medicine Objective: Rare coexistence of disease or pathology Background:Bell’s palsy, also called facial nerve palsy, occasionally co-occurs with trigeminal neuropathy, which presents as additional facial sensory symptoms and/or neck pain. Bell’s palsy has a proposed viral etiology, in particular when occurring after dental manipulation.Case Report:A 52-year-old Asian woman presented to a chiropractor with a 3-year history of constant neck pain and left-sided maxillary, eyebrow, and temporomandibular facial pain, paresis, and paresthesia, which began after using a toothpick, causing possible gum trauma. She had previously been treated with antiviral medication and prednisone, Chinese herbal medicine, and acupuncture, but her recovery plateaued at 60% after 1 year. The chiropractor ordered cervical spine magnetic resonance imaging, which demonstrated cervical spondylosis, with no evidence of myelopathy or major pathology. Treatment involved cervical and thoracic spinal manipulation, cervical traction, soft-tissue therapy, and neck exercises. The patient responded positively. At 1-month follow-up, face and neck pain and facial paresis were resolved aside from residual eyelid synkinesis. A literature review identified 12 additional cases in which chiropractic spinal manipulation with multimodal therapies was reported to improve Bell’s palsy. Including the current case, 85% of these patients also had pain in the face or neck.Conclusions:This case illustrates improvement of Bell’s palsy and concurrent trigeminal neuropathy with multimodal chiropractic care including spinal manipulation. Limited evidence from other similar cases suggests a role of the trigeminal pathway in these positive treatment responses of Bell’s palsy with concurrent face/neck pain. These findings should be explored with research designs accounting for the natural history of Bell’s palsy.

Effectiveness of Multimodal Chiropractic Care Featuring Spinal Manipulation for Persistent Spinal Pain Syndrome Following Lumbar Spine Surgery: Retrospective Chart Review of 31 Adults in Hong Kong.

BackgroundThe term “persistent spinal pain syndrome type 2” (PSPS-2) has been proposed by the International Association for the Study of Pain to replace the term “failed back surgery syndrome”. This retrospective study aimed to evaluate effectiveness of multimodal care featuring chiropractic spinal manipulation (CSMT) in 31 adults in Hong Kong with PSPS-2.Material/MethodsWe identified new adult patients with PSPS-2 receiving CSMT from 2016 to 2018. Demographic and clinical data and baseline/follow-up numeric pain rating scale (NPRS) and Oswestry Disability Index (ODI) scores were extracted. Multiple linear regression was used to examine posttreatment NPRS and ODI reduction, with clinical variables as covariates.ResultsOf 6589 patients with low back pain, 31 met criteria (mean age 52.2±13.7 years). Surgeries included laminectomy (81%), discectomy (13%), and fusion (6%). Mean baseline NRPS was 6.6±1.9; ODI was 43.8±15.1%. Patients received CSMT (100%), drop technique (81%), passive modalities (65%), soft tissue manipulation (13%), flexion-distraction (13%), and mechanical traction (13%). Mean posttreatment NPRS was 0.6±1.0; ODI was 2.4±3.3%. All patients had a minimum clinically important difference for NPRS (≥2/10) and ODI (≥30%). One year after treatment, 48% maintained improvement, 42% experienced recurrence; in 10%, follow-up was unavailable. Regression analysis identified younger age, shorter symptom duration, and greater baseline NPRS as predictors of NPRS reduction; and greater baseline ODI as a predictor of ODI reduction (all P<0.05).ConclusionsPatients with PSPS-2 improved with multimodal care featuring CSMT, which was more effective in patients with younger age, shorter symptom duration, and higher baseline pain or disability levels.

Spinal Kinematic Assessment of Chiropractic Side-Posture Adjustments: Development of a Motion Capture System

ObjectiveThe purpose of this study was to develop a protocol and a data analysis system for the assessment of postures and movements of doctors of chiropractic during side-posture adjustments (SPAs), otherwise known as side-posture chiropractic spinal manipulation. MethodsFor this study, an experienced chiropractor performed Gonstead-style lumbar SPAs on 10 participants. We used an inertial measurement unit system to record spinal angular motions and analyzed data with a custom application written in Microsoft Excel. ResultsData collection was successful for all trials. We identified postural angles at the time of set-up and thrust and maximum and minimum angles in a period centered on the thrust. All spinal regions of the chiropractor were flexed during the entire period; otherwise, movement patterns were characterized by biphasic wavelike motions, which begin before the time of the thrust and finish afterward. Within each region and plane of motion, patterns were qualitatively similar between participants, but time of thrust was not consistent within the patterns. There was a wide range of angular velocities, and the fastest was measured in the chiropractor's cervical and thoracic regions. ConclusionIn this study, we developed a protocol and a data analysis system for assessment of chiropractors’ postures and movements during SPAs. The protocol may be useful to future investigators who wish to use similar methods for educational purposes or to examine the role of optimal or suboptimal movement patterns in occupational injuries of doctors of chiropractic.

Cross-Sectional Survey of Opinions, Professional Changes, and Personal Hardships of COVID-19 on Chiropractors in the United States

ObjectiveThe purpose of this study was to assess self-reported data from a sample of U.S. doctors of chiropractic during the COVID-19 pandemic about levels of psychological stress and beliefs of the association between chiropractic spinal manipulation and the immune system. MethodsChiropractors in the United States were invited via social media and e-mail to complete a survey about chiropractic and COVID-19. The survey collected demographic information, office protocols, changes made during the COVID-19 pandemic, chiropractic profession opinions, information related to stress, and personal beliefs from April 19 to May 3 of 2020. Data were analyzed using descriptive statistics. ResultsOf approximately 77000 U.S.-licensed chiropractors,750 responded. Of this sample, 51.2% reported moderate and 30.4% reported severe levels of psychological stress. The primary stressors were financial and business concerns. There was a mixed response regarding beliefs if there was evidence to support a connection between spinal manipulation and the immune system. A majority (76.1%) responded that there should be no advertising for immune-boosting effects of spinal manipulation during the pandemic. A minority (18.3%) reported adding use of telehealth to deliver their services. ConclusionA majority of chiropractors included in this survey reported that the COVID-19 pandemic caused them psychological stress. More than half of the respondents reported moderate stress, with the second highest number of respondents reporting severe stress. Subgroup differences were noted in stress levels and causes, as well as pandemic-related practice changes. A dichotomy was noted between beliefs and recommended actions about effects on the immune system, which may represent that providers are aware of current evidence and considering association recommendations.

Man With Headache

A 34-year-old man presented to the emergency department with 1 day of sudden-onset headache after chiropractic cervical spinal manipulation. He had nausea with a postural headache that was relieved by lying flat. He had a nonfocal neurologic examination and underwent computed tomography (CT) angiography of the head and neck, which demonstrated no vascular dissection or subarachnoid hemorrhage. Neurology was consulted and recommended magnetic resonance imaging (MRI) of the brain and cervical spine (Figures 1-3).

Association Between Psychosocial Parameters and Response to Chiropractic Care Among Older Adults With Chronic Low Back Pain: Secondary Analysis of a Randomized Clinical Trial

ObjectivesThe purpose of this study was to determine whether baseline self-efficacy, fear of pain with movement (kinesiophobia), or change in either were associated with clinically important improvement in disability among older adults with chronic low back pain after 12 weeks of chiropractic spinal manipulation (CSM) and exercise. MethodsThis secondary analysis used randomized trial data from community-dwelling adults aged 65 years or older with chronic spinal disability who received non-pharmacological treatment of CSM and exercise. Those with ≥30% reduction in the Oswestry Disability Index (ODI) after 12 weeks of treatment were considered responders to care. Psychosocial measures included the Pain Self-Efficacy Questionnaire (PSEQ) and the Tampa Scale of Kinesiophobia (TSK). Logistic regression–assessed associations were between psychosocial, demographic, and low back predictors and 30% ODI improvement. ResultsThere were 176 community-dwelling older adults included in this analysis. Mean age was 71 years, 59.7% were women; 176 (96.7%) had complete data. Baseline disability (ODI = 26.1 ± 9.3) and back pain (5.0 ± 1.9, 0-10 scale) were moderate. Baseline PSEQ reflected higher self-efficacy (47.7 ± 7.8, 0-60 scale) with minimal kinesiophobia (TSK 34.3 ± 5.2, 17-68 scale). Seventy-two (40.9%) achieved 30% reduction in ODI (mean –5.4 ± 7.9) after 12 weeks of treatment. Mean self-efficacy improvement was clinically important (2.5 ± 6.5 points); kinesiophobia (–2.7 ± 4.4 points) and LBP (–1.6 points) also improved. Baseline PSEQ and percent improvement in PSEQ and TSK were associated with response to treatment in univariate regression analyses but not in multiple regression models that included low back predictors. LBP duration >4 years negatively impacted recovery. ConclusionsAmong this sample of older adults who received chiropractic manipulation and exercise, baseline self-efficacy and improvements in self-efficacy and kinesiophobia were individually associated with clinically important reductions in disability post-intervention, although not in adjusted models when LBP duration was included.

Segmental Chiropractic Spinal Manipulation Does not Reduce Pain Amplification and the Associated Pain-Related Brain Activity in a Capsaicin-Heat Pain Model.

Musculoskeletal injuries lead to sensitization of nociceptors and primary hyperalgesia (hypersensitivity to painful stimuli). This occurs with back injuries, which are associated with acute pain and increased pain sensitivity at the site of injury. In some cases, back pain persists and leads to central sensitization and chronic pain. Thus, reducing primary hyperalgesia to prevent central sensitization may limit the transition from acute to chronic back pain. It has been shown that spinal manipulation (SM) reduces experimental and clinical pain, but the effect of SM on primary hyperalgesia and hypersensitivity to painful stimuli remains unclear. The goal of the present study was to investigate the effect of SM on pain hypersensitivity using a capsaicin-heat pain model. Laser stimulation was used to evoke heat pain and the associated brain activity, which were measured to assess their modulation by SM. Eighty healthy participants were recruited and randomly assigned to one of the four experimental groups: inert cream and no intervention; capsaicin cream and no intervention; capsaicin cream and SM at T7; capsaicin cream and placebo. Inert or capsaicin cream (1%) was applied to the T9 area. SM or placebo were performed 25 min after cream application. A series of laser stimuli were delivered on the area of cream application (1) before cream application, (2) after cream application but before SM or placebo, and (3) after SM or placebo. Capsaicin cream induced a significant increase in laser pain (p < 0.001) and laser-evoked potential amplitude (p < 0.001). However, SM did not decrease the amplification of laser pain or laser-evoked potentials by capsaicin. These results indicate that segmental SM does not reduce pain hypersensitivity and the associated pain-related brain activity in a capsaicin-heat pain model.

Clinical Effectiveness and Efficacy of Chiropractic Spinal Manipulation for Spine Pain.

Spine pain is a highly prevalent condition affecting over 11% of the world's population. It is the single leading cause of activity limitation and ranks fourth in years lost to disability globally, representing a significant personal, social, and economic burden. For the vast majority of patients with back and neck pain, a specific pathology cannot be identified as the cause for their pain, which is then labeled as non-specific. In a growing proportion of these cases, pain persists beyond 3 months and is referred to as chronic primary back or neck pain. To decrease the global burden of spine pain, current data suggest that a conservative approach may be preferable. One of the conservative management options available is spinal manipulative therapy (SMT), the main intervention used by chiropractors and other manual therapists. The aim of this narrative review is to highlight the most relevant and up-to-date evidence on the effectiveness (as it compares to other interventions in more pragmatic settings) and efficacy (as it compares to inactive controls under highly controlled conditions) of SMT for the management of neck pain and low back pain. Additionally, a perspective on the current recommendations on SMT for spine pain and the needs for future research will be provided. In summary, SMT may be as effective as other recommended therapies for the management of non-specific and chronic primary spine pain, including standard medical care or physical therapy. Currently, SMT is recommended in combination with exercise for neck pain as part of a multimodal approach. It may also be recommended as a frontline intervention for low back pain. Despite some remaining discrepancies, current clinical practice guidelines almost universally recommend the use of SMT for spine pain. Due to the low quality of evidence, the efficacy of SMT compared with a placebo or no treatment remains uncertain. Therefore, future research is needed to clarify the specific effects of SMT to further validate this intervention. In addition, factors that predict these effects remain to be determined to target patients who are more likely to obtain positive outcomes from SMT.

Chiropractic Spinal Manipulation Prevents Secondary Hyperalgesia Induced by Topical Capsaicin in Healthy Individuals.

Background and Aims: Spinal manipulation (SM) is currently recommended for the management of back pain. Experimental studies indicate that the hypoalgesic mechanisms of SM may rely on inhibition of segmental processes related to temporal summation of pain and, possibly, on central sensitization, although this remains unclear. The aim of this study was to determine whether experimental back pain, secondary hyperalgesia, and pain-related brain activity induced by capsaicin are decreased by segmental SM.Methods: Seventy-three healthy volunteers were randomly allocated to one of four experimental groups: SM at T5 vertebral level (segmental), SM at T9 vertebral level (heterosegmental), placebo intervention at T5 vertebral level, or no intervention. Topical capsaicin was applied to the area of T5 vertebra for 40 min. After 20 min, the interventions were administered. Pressure pain thresholds (PPTs) were assessed outside the area of capsaicin application at 0 and 40 min to examine secondary hyperalgesia. Capsaicin pain intensity and unpleasantness were reported every 4 min. Frontal high-gamma oscillations were also measured with electroencephalography.Results: Pain ratings and brain activity were not significantly different between groups over time (p > 0.5). However, PPTs were significantly decreased in the placebo and control groups (p < 0.01), indicative of secondary hyperalgesia, while no hyperalgesia was observed for groups receiving SM (p = 1.0). This effect was independent of expectations and greater than placebo for segmental (p < 0.01) but not heterosegmental SM (p = 1.0).Conclusions: These results indicate that segmental SM can prevent secondary hyperalgesia, independently of expectations. This has implications for the management of back pain, particularly when central sensitization is involved.

Neurophysiological mechanisms of chiropractic spinal manipulation for spine pain

AbstractTogether, neck pain and back pain are the first cause of disability worldwide, accounting for more than 10% of the total years lived with disability. In this context, chiropractic care provides a safe and effective option for the management of a large proportion of these patients. Chiropractic is a healthcare profession mainly focused on the spine and the treatment of spinal disorders, including spine pain. Basic studies have examined the influence of chiropractic spinal manipulation (SM) on a variety of peripheral, spinal and supraspinal mechanisms involved in spine pain. While spinal cord mechanisms of pain inhibition contribute at least partly to the pain‐relieving effects of chiropractic treatments, the evidence is weaker regarding peripheral and supraspinal mechanisms, which are important components of acute and chronic pain. This narrative review highlights the most relevant mechanisms of pain relief by SM and provides a perspective for future research on SM and spine pain, including the validation of placebo interventions that control for placebo effects and other non‐specific effects that may be induced by SM.SignificanceSpinal manipulation inhibits back and neck pain partly through spinal segmental mechanisms and potentially through peripheral mechanisms regulating inflammatory responses. Other mechanisms remain to be clarified. Controls and placebo interventions need to be improved in order to clarify the contribution of specific and non‐specific effects to pain relief by spinal manipulative therapy.