Søren O’Neill

• Ph.D., M.Rehab., DC.
• Professor at University of Southern Denmark

Chronic pain is often associated with hyperalgesia in cross-sectional studies. In the present study, a random cohort of 40-year-old individuals (n = 264) from the general population was assessed for low back pain (LBP) status and pressure pain threshold (PPT), with follow-up assessment 4 and 8 years later. Low PPT at baseline as a potential risk fa...

Quantitative sensory testing has indicated generalized muscle hyperalgesia in patients with chronic low back pain. The temporal development of such hyperalgesia is not well understood. The aim of the present study was to demonstrate whether generalized muscle hyperalgesia can develop within minutes of acute low back pain using a new experimental mo...

Some chronic painful conditions including e.g. fibromyalgia, whiplash associated disorders, endometriosis, and irritable bowel syndrome are associated with generalized musculoskeletal hyperalgesia. The aim of the present study was to determine whether generalized deep-tissue hyperalgesia could be demonstrated in a group of patients with chronic low...

Background Pain profiles (e.g. pro‐ and anti‐nociceptive) can be developed using quantitative sensory testing (QST) but substantial variability exists. This study describes the variability in temporal summation of pain (TSP) and conditioned pain modulation (CPM) in chronic musculoskeletal pain patients, proposes cut‐off values, and explores the ass...

Background Despite the use of Patient‐Drawn Pain Drawings (PDPDs) in clinical settings, their validity as indicators of psychological distress remains debated. We aimed to assess the association between PDPD areas and physical health and psychological variables. Methods This study analysed digitally‐drawn PDPDs from 15,345 chronic low back pain (L...

Introduction Clinicians commonly use manual therapy to treat low back pain by palpating the spine to identify the spinous processes. This study aims to evaluate the ability of experienced clinicians to consistently locate the spinous processes from S1 to T12 through palpation. The results will be compared to topographical data representing the lumb...

Objective This study investigated patient satisfaction with care provided by chiropractic students under supervision vs supervisors in a Danish hospital setting. Methods A cross-sectional observational study of patient satisfaction was conducted at the Spine Center of Southern Denmark, where chiropractic students from the University of Southern De...

The variability in pain drawing styles and analysis methods has raised concerns about the reliability of pain drawings as a screening tool for nonpain symptoms. In this study, a data-driven approach to pain drawing analysis has been used to enhance the reliability. The aim was to identify distinct clusters of pain patterns by using latent class ana...

In a previous paper, we presented some important weaknesses of and threats to the chiropractic profession as we see them. We further argued that the chiropractic profession’s relationship with its principal clinical tool (spinal manual therapy) is at the core of the ideological divide that fractures the profession and prevents professional developm...

Spinal manual therapy is central to chiropractic history, clinical practice, and professional identity. That chiropractors have developed an expertise in this domain has provided some considerable advantages. However, we contend it is also at the crux of the ideological schism that fractures the chiropractic profession. In this article, which is th...

Temporal summation of pressure pain is technically more challenging than simple pressure pain thresholds. The current study describes the design, manufacture and validation of a simple mechanical test apparatus to assess the temporal summation of deep pressure pain. We release design details into the public domain with the intention of providing fr...

Quantitative sensory testing (QST) is a commonly applied paradigm to investigate pain, which is a subjective experience influenced by a myriad of social and contextual factors. Therefore, it is important to consider the potential sensitivity of QST to the test setting and the social interaction that naturally is a part of it. This may particularly...

Background: Persistent and severe low back pain is challenging to treat. Multidisciplinary care with systematic follow-up may be more effective than usual care. However, such a model has yet to be developed and tested. Objective: Our objectives were to develop and test the feasibility of a three-month multidisciplinary intervention with systemat...

Purpose: The six-minute walk test (6MWT) can assess walking function but is time-consuming. We investigate the correlation of performance over the first two minutes of the 6MWT (2MWT#) and the 6MWT. We also evaluate the 2MWT#'s ability to predict 6MWT results, assess correlations to secondary explanatory outcomes, and assess the ability to discrim...

Objectives Conditioned pain modulation is a commonly used quantitative sensory test, measuring endogenous pain control. The temporal stability of the test is questioned, and there is a lack of agreement on the effect of different pain conditions on the conditioned pain modulation response. Thus, an investigation of the temporal stability of a condi...

Background Changes in pain sensitivity are a commonly suggested mechanism for the clinical effect of spinal manipulative therapy (SMT). Most research has examined pressure pain thresholds (PPT) and has primarily been conducted in controlled experimental setups and on asymptomatic populations. Many important factors are likely to differ between rese...

Background Persistent or recurrent neck pain is associated with perturbations in the autonomic nervous system balance, and nociceptive stimulation has been seen to influence this balance. However, very few prospective studies have addressed the extent to which changes in pain associate with changes in autonomic cardiac regulation. Therefore, we inv...

Background and aims: Studies show that there are clinical differences between multi-site pain and mono-site pain. There is a strong linear association between the number of pain sites and reduction in overall health and higher psychological distress. Previous research has mostly used few pain sites and arbitrary grouping criteria. The purpose of th...

Objectives: Existing equipment for quantitative sensory testing is generally expensive and not easily applicable in a clinical setting thus simple bed-side devices are warranted. Pressure hyperalgesia is a common finding in patients with musculoskeletal pain and an experimental model is delayed-onset muscle soreness (DOMS). DOMS is characterised b...

The concept that spinal manipulation therapy (SMT) outcomes are optimized when the treatment is aimed at a clinically relevant joint is commonly assumed and central to teaching and clinical use (candidate sites). This systematic review investigated whether clinical effects are superior when this is the case compared to SMT applied elsewhere (non-ca...

Background Pain hypersensitivity can be assessed using Quantitative Sensory Testing (QST) and is associated with persistent low back pain. Spinal manipulation appears to modify pain hypersensitivity, and this could function as one mechanism leading to clinical improvements. In the current study, we applied a comprehensive QST battery to assess pain...

An amendment to this paper has been published and can be accessed via the original article.

Introduction Little is known about the underlying biomechanical cause of low back pain (LBP). Recently, technological advances have made it possible to quantify biomechanical and neurophysiological measurements, potentially relevant factors in understanding LBP etiology. However, few studies have explored the relation between these factors. This st...

Background Some chiropractors suggest that chiropractic treatment is appropriate for health issues other than musculoskeletal problems. The prevalence of such claims on individual clinic websites has previously been reported as approximately one-in-four in Denmark. The underlying rationales for such claims may reflect convictions about traditional...

Background Recurrent or persistent neck pain affects a vast number of people globally, leading to reduced quality of life and high societal costs. Clinically, it is a difficult condition to manage, and treatment effect sizes are often moderate at best. Activity and manual therapy are first-line treatment options in current guidelines. We aimed to i...

Objectives The aim of the current study was to examine the convergent validity of the Central Sensitization Inventory by quantifying the correlation with experimental measures of pain sensitivity and self-reported psycho-social questionnaires, in a low back pain population. Methods All participants were recruited from an outpatient hospital spine...

Background The sensation of spinal stiffness is a commonly reported symptom among back pain patients, with the clinical assessment of spinal stiffness usually being part of the decision-making process when deciding on providing manual treatment of low back pain. While any relationship between spinal stiffness and low back pain is likely to be multi...

Objectives The literature on conditioned pain modulation (CPM) is inconclusive in relation to low-back pain and it is unclear how CPM affects temporal summation as a proxy of central pain integration. The aim of this study was to examine whether the CPM effect would be different on pain induced by temporal summation than single stimuli in a group o...

Background A small proportion of chiropractors, osteopaths, and other manual medicine providers use spinal manipulative therapy (SMT) to manage non-musculoskeletal disorders. However, the efficacy and effectiveness of these interventions to prevent or treat non-musculoskeletal disorders remain controversial. Objectives We convened a Global Summit...

Background In a prior randomized trial, we demonstrated that participants receiving spinal manipulative therapy at a pain-sensitive segment instead of a stiff segment experienced increased mechanical pressure pain thresholds. We hypothesized that the targeted segment mediated this increase through a segment-dependent neurophysiological reflective p...

Background Objectively measured reduction in lumbar posterior-to-anterior (PA) stiffness is associated with pain relief in some, but not all persons with low back pain. Unfortunately, these measurements can be time consuming to perform. In comparison, the Lumbar Spine Instability Questionnaire (LSIQ) is intended to measure spinal instability and th...

Background: The chiropractic profession is split between those practicing evidence-based and those whose practice is honed by vitalism. The latter has been coined ‘chiropractic conservatism’. In Denmark, the chiropractic education program is university-based in close collaboration with a medical faculty. We wanted to investigate if such conservativ...

Background: The Danish Authorisation Act sets out the chiropractic scope of practice. Under this legislation the scope of practice is diagnostics, prevention and treatment of biomechanical disorders of the spine, pelvis and extremities. Despite this and an international movement toward a scientifically active, evidence-based profession with a focu...

Background In March 2020, the World Health Organization elevated the coronavirus disease (COVID-19) epidemic to a pandemic and called for urgent and aggressive action worldwide. Public health experts have communicated clear and emphatic strategies to prevent the spread of COVID-19. Hygiene rules and social distancing practices have been implemented...

The present study was undertaken to determine the prevalence of endplate junction failure in a smaller cohort of Danish patients with lumbar disk herniation and compare this to the previously published data from India. Consecutive patients seen in a large regional hospital spine-care unit, with a clinical presentation suggesting a lumbar disk herni...

The mechanisms underlying pain relief following spinal manipulative therapy (SMT) are not understood fully although biomechanical and neurophysiological processes have been proposed. As such, we designed this randomized trial to elucidate the contributions of biomechanical and neurophysiological processes. A total of 132 participants with low back...

Introduktion Mellem 10 og 20 % af de patienter, der ses i almen praksis med et laende-problem, har tegn på nerverodspåvirkning som følge af diskusprolaps, og det kan vaere en udfordrende diagnose at stille i en travl hverdag. Laenderygsmerter er en af de hyppigste henvendelsesårsager hos prakti-serende laeger, og alligevel udgør diagnosefejl i grup...

Background The chiropractic profession is split between those practicing evidence-informed and those whose practice is honed by vitalism. The latter has been coined ‘chiropractic conservatism’. Concerningly, this behavior is also present in students, as a recent survey conducted on students from a European private chiropractic college showed that c...

Background We investigated whether a university-based educational system would overrule the strong link (odds ratios >20) between chiropractic conservatism and the inability to recognize non-indications to chiropractic treatment that had been shown to exist in a previous study of a private chiropractic college. We i) sought to define the clinical d...

Background and aims Using a computer algorithm to quantify pain drawings could be useful, especially when large numbers of drawings need to be assessed. Whilst informal visual assessment of pain drawings can give clinicians a quick impression of the extent of pain and its location, formal quantification of pain drawings by computer for research pur...

Background: Recent experimental research has suggested that spinal manipulative therapy (SMT) may reduce pain through modulation of the ascending pain signals and/or the central pain-regulating mechanisms. People with persistent neck pain (NP) have also been found to have disturbances in autonomic nervous system (ANS) regulation. A common way to s...

Objective: We describe the experiences and lessons learned from establishing a 5-year postgraduate hospital-based residency program for chiropractors in Denmark. The program was established with the aim of qualifying those chiropractors to undertake common and several specialized functions in relation to musculoskeletal disorders, at the highest p...

Within the last 5 years, international research collaborations including those of several research groups skilled in microbiology, immunology and pathophysiology, have identified a low-virulent intradiscal infection with the ability to provoke gradual and progressive disc degeneration, end-plate disruption, Modic changes and persistent clinical low...

Background and aims The choice of testing site for quantitative sensory testing (QST) of pain sensitivity is important and previous studies have demonstrated patterns in pain sensitivity within discrete areas in different body regions. Some areas are characterized by a relatively high degree of spatial pain discrimination and recognizable patterns...

Objectives: Pain perception and pain behaviors are distinct phenomena with different functions. Pain behaviors are protective in their functions, which include eliciting empathy or caring behaviors from others. Moreover, pain behaviors are intertwined with interpersonal relationships with significant others, which is why attachment orientations ha...

Abstract Background Manual assessment of muscle strength is often graded using the ordinal Medical Research Council (MRC) scale. The scale has a number of inherent weaknesses, including poorly defined limits between grades ‘4’ and ‘5’ and very large differences in the span of muscle strength encompassed by each of the six grades. It is not necessar...

Background: High-velocity low-amplitude (HVLA) spinal manipulation is commonly used in the treatment of spinal pain syndromes. The mechanisms by which HVLA-manipulation might reduce spinal pain are not well understood, but often assumed to relate to the reduction of biomechanical dysfunction. It is also possible however, that HVLA-manipulation inv...

The reliability of quantitative sensory testing (QST) is affected by the error attributable to both test occasion and rater (examiner) as well as interactions between them. Most reliability studies only account for one source of error. The present study employed a fully-crossed, multivariate generalizability design to account for rater and occasion...

Generalized hyperalgesia, a widespread increased sensitivity to painful stimuli, has been demonstrated in a range of chronic pain conditions including low-back pain. The evidence suggests, that generalized hyperalgesia may be an important factor in the development of chronicity, but it is not commonly assessed in clinical practice. Whereas a range...

A limited number of quantitative sensory pain tests (QST) were selected on the basis of ease of application and interpretation in a clinical setting. QST results were summarized as a composite score on a scale of zero to four which was deemed to facilitate clinical interpretation. The QST set was used to investigate differences in pain sensitivity...

Generalized hyperalgesia has been demonstrated in cross-sectional stud- ies in a range of chronic pain disorders, including low-back pain. It is not clear, whether the increased sensitivity to experimental pain stim- uli in chronic low-back pain sufferers develops early with acute pain, later with chronification, or whether it actually represents p...