Neurophysiological Mechanisms Research Articles

Advancing musculoskeletal diagnosis and therapy: a comprehensive review of trigger point theory and muscle pain patterns.

Musculoskeletal disorders, especially chronic muscle pain, have a significant impact on public health, affecting millions worldwide. This review examines recent advancements in the diagnosis and management of myofascial pain, with a focus on the refined application of trigger point theory. This theory now incorporates an intricate model that blends biomechanical and neurophysiological mechanisms, essential for understanding the initiation and persistence of pain, and necessitating targeted therapeutic interventions. Utilizing a methodical approach, this paper categorizes muscle pain into three types: Muscle Belly Pain, Origin-Insertion Pain, and Referred Pain, as delineated in the most recent edition of "Myofascial Pain and Dysfunction-The Trigger Point Manual." Such classification enhances diagnostic precision and therapeutic effectiveness by establishing a specific treatment protocol for each type of pain. The paper discusses the implications of various treatments, such as dry needling and manual therapy, which are informed by empirically derived trigger point charts. These charts are instrumental in pinpointing the exact locations of pain sources and customizing treatment plans. Moreover, this review critically assesses the evolving nature of trigger point charts and champions a holistic approach to pain management. It underscores the necessity of integrating biomechanics, kinesiology, and compensatory mechanisms to provide a comprehensive understanding that allows practitioners to address not only symptomatic pain but also the root causes of musculoskeletal disorders, thereby enhancing long-term patient care outcomes in clinical environments.

Change in Walking Parameters of Paralympic Athletes Diagnosed with Cerebral Palsy Using WALKBOT Training System at Recovery Stage of Rehabilitation

INTRODUCTION: The publication is devoted to studying the rehabilitative effect of the Walkbot innovative training system on restoring the walking function in Paralympic athletes diagnosed with cerebral palsy (CP). The novelty of the developed Walkbot robot-assisted training system (TS) and insufficient experience of its use in rehabilitation practice require investigations on contingents of patients with musculoskeletal disorders in CP to develop protocols and programs of the rehabilitation use of the Walkbot TS. AIM: Study of effectiveness of rehabilitation use of the Walkbot robotic TS to restore the walking function in Paralympic athletes with spastic cerebral palsy. MATERIALS AND METHODS: The study was conducted at the Medical Rehabilitation Center ‘Sergievskie Mineral Waters’ in 2023. Forty Paralympic athletes (all men) aged 30-35 years were examined. The experimental group (EG) and control group (CG) included 20 Paralympic athletes each with standardization of the groups by the main parameters. The classes were conducted for 60 minutes according to the rehabilitation program. In the experimental group, besides exercise therapy (ET), the participants also exercised on the robotic Walkbot TS to restore the walking function, namely, they used Go world game with the known tasks symbolizing counties of the world, Go palace game that permits to take a walk around the palace, when patients move to the right or left as they choose; Go undersea game occurring against the background of a fairy sea world where they must go through the route controlling the direction of movement. The Paralympians of the control group used the standard rehabilitation program including ET with no training and gaming technologies. RESULTS: The obtained results showed a pronounced improvement in the parameters of motor actions in Paralympians of the EG, while in the CG, positive rehabilitation changes were 2–3 times less expressed. At the initial and final rehabilitation stages, an increase of the tolerated duration of classes was recorded: by 5 times in the EG and 3 times in the CG, post-rehabilitation increase in the EG was 23.4% compared to that in CG. After training on the Walkbot TS, the volume of the performed load increased 5.9 times in the EG and 2.1 times in the CG. The increase in the EG made 64.5% compared to the CG, which indicated an increase in speed-strength qualities and endurance of para-athletes. At the end of rehabilitation, the amount of steps on the Walkbot TS in the EG increased 5.9 times (in the CG — 2.9 times), increase in the EG made 48.3% compared to the CG. CONCLUSION: The experiment established a complex multisided positive effect of training sessions on the Walkbot TS in the EG versus the effect of only exercise therapy in the CG. The obtained data suggest that training on the Walkbot TS confer a significant restorative and normalizing effect on the neurophysiological mechanisms of functioning of the central parts of the motor cortex.

Ischemic preconditioning: what else can it do…?

Ischemic preconditioning (IPC) can enhance maximal strength likely due to neural priming. Cruz et al. (Cruz R, Tramontin AF, Oliveira AS, Caputo F, Denadai BS, Greco CC. Scand J Med Sci Sports 34: e14591, 2024) examined the neurophysiological mechanisms responsible for the ergogenic effect. Although key neurophysiological measures remained largely unchanged, voluntary activation and maximal strength were greater following IPC than sham-IPC. Although the mechanistic evidence remains inconclusive, the greater maximal strength provides further evidence of the ergogenic benefit of IPC. Researchers should continue examining the broader functional implications of IPC.

Aberrant Intra- and Inter-Network Connectivity in Idiopathic Sudden Sensorineural Hearing Loss with Tinnitus.

Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL) is related to alterations in brain cortical and subcortical structures, and changes in brain functional activities involving multiple networks, which is often accompanied by tinnitus. There have been many in-depth research studies conducted concerning ISSNHL. Despite this, the neurophysiological mechanisms of ISSNHL with tinnitus are still under exploration. The study aimed to investigate the neural mechanism in ISSNHL patients with tinnitus based on the alterations in intra- and inter-network Functional Connectivity (FC) of multiple networks. Thirty ISSNHL subjects and 37 healthy subjects underwent resting-state functional Magnetic Resonance Imaging (rs-fMRI). Independent Component Analysis (ICA) was used to identify 8 Resting-state Networks (RSNs). Furthermore, the study used a two-sample t-test to calculate the intra-network FC differences, while calculating Functional Network Connectivity (FNC) to detect the inter-network FC differences. By using the ICA approach, tinnitus patients with ISSNHL were found to have FC changes in the following RSNs: CN, VN, DMN, ECN, SMN, and AUN. In addition, the interconnections of VN-SMN, VN-ECN, and ECN-DAN were weakened. The present study has demonstrated changes in FC within and between networks in ISSNHL with tinnitus, providing ideas for further study on the neuropathological mechanism of the disease.

Individual posterior alpha rhythms and cognitive reserve as possible early prognostic markers in people with subjective memory complaints

Subjective memory complaints (SMCs) are a memory disorder that often precedes mild cognitive impairment (MCI) or Alzheimer’s disease (AD). Both individual alpha rhythms and cognitive reserve (CR) represent key features of SMCs and provide useful tools to characterize and predict the course of the disorder. We studied whether older people with SMCs may also present some abnormal resting state electroencephalogram (rsEEG) alpha rhythms, and whether alpha rhythms are associated with CR. To do this, eyes-closed rsEEG were recorded in 68 older people with and without SMCs. The individual alpha indexes alpha/theta transition frequency (TF) and individual alpha frequency peak (IAFp) were computed. TF and IAFp were also used to determine the alpha1, alpha2, and alpha3 power frequency. Results indicated no differences in TF or IAFp between older people with SMCs and controls. The SMCs group showed a reduction in alpha3 power in comparison with controls. Specifically, women with SMCs were characterized by a significant decrease in alpha3 power compared to control women. Furthermore, only in SMCs group, greater CR was associated with slow IAFp. In sum, these results suggest that TF and IAFp are two stable indexes that are not influenced by the presence of SMCs. However, the reduction in alpha3, as observed in women with SMCs, shows an abnormal posterior rsEEG at alpha power. Finally, the compensatory mechanisms of CR appear to interact with the neurophysiological mechanisms that underlie the regulation of alpha rhythms.

Sensori-motor neurofeedback improves inhibitory control and induces neural changes: a placebo-controlled, double-blind, event-related potentials study

Background/ObjectiveInhibition is crucial for controlling behavior and is impaired in various psychopathologies. Neurofeedback holds promise in addressing cognitive deficits, and experimental research is essential for identifying its functional benefits. This study aimed to investigate whether boosting sensorimotor activity (SMR) improves inhibitory control in a final sample of healthy individuals (N = 53), while exploring the underlying neurophysiological mechanism. MethodParticipants were randomly divided into two groups: one receiving SMR neurofeedback training to enhance sensorimotor activity within the 12–15 Hz frequency range, and the other receiving sham feedback. Inhibition performance and neural correlates were evaluated with a Go-NoGo task before (T0) and after (T1) 10 neurofeedback sessions using event-related potentials. Data were analyzed via ANOVAs and regression analyses. ResultsCompared to placebo, the active group demonstrated higher absolute SMR power (p = 0.040) and improvements in inhibitory control, including faster response times and fewer inhibition errors (p < 0.001, d = 6.06), associated with a larger NoGoP3d amplitude (p < 0.001, d = 3.35). A positive correlation between the increase in SMR power and the rise in NoGoP3d amplitude (β=0.46, p = 0.015) explains 21 % of the observed variance. ConclusionsUptraining SMR power is linked to heightened utilization of neural resources for executing optimal inhibition responses. These results uphold its effectiveness in cognitive rehabilitation.

The neurophysiological mechanisms of medial prefrontal-perirhinal cortex circuit mediating temporal order memory decline in early stage of AD rats

The temporal component of episodic memory has been recognized as a sensitive behavioral marker in early stage of Alzheimer's disease (AD) patients. However, parallel studies in AD animals are currently lacking, and the underlying neural circuit mechanisms remain poorly understood. Using a novel AppNL-G-F knock-in (APP-KI) rat model, the developmental changes of temporal order memory (TOM) and the relationship with medial prefrontal cortex and perirhinal cortex (mPFC-PRH) circuit were determined through in vivo electrophysiology and microimaging technique. We observed a deficit in TOM performance during the object temporal order memory task (OTOMT) in APP-KI rats at 6 month old, which was not evident at 3 or 4 months of age. Alongside behavioral changes, we identified a gradually extensive and aggravated regional activation and functional alterations in the mPFC and PRH during the performance of OTOMT, which occurred prior to the onset of TOM deficits. Moreover, coherence analysis showed that the functional connectivity between the mPFC and PRH could predict the extent of future behavioral performance. Further analysis revealed that the aberrant mPFC-PRH interaction mainly attributed to the progressive deterioration of synaptic transmission, information flow and network coordination from mPFC to PRH, suggesting the mPFC dysfunction maybe the key area of origin underlying the early changes of TOM. These findings identify a pivotal role of the mPFC-PRH circuit in mediating the TOM deficits in the early stage of AD, which holds promising clinical translational value and offers potential early biological markers for predicting AD memory progression.

PROSPECTS AND LIMITS OF ARTIFICIAL INTELLIGENCE IN THE CONTEXT OF NATURAL INTELLIGENCE (philosophical and methodological aspects) / ПЕРСПЕКТИВЫ И ПРЕДЕЛЫ ВОЗМОЖНОСТЕЙ ИСКУССТВЕННОГО ИНТЕЛЛЕКТА В КОНТЕКСТЕ ЕСТЕСТВЕННОГО ИНТЕЛЛЕКТА (философско-методологические аспекты)

Artificial intelligence is characterized as non-living intelligence, although attempts are being made to pass from the principles of biological neural networks to artificial living neural networks. The human brain is assumed to be a complex system of physicochemical neurophysiological biochemical integration of neural networks, which encodes a specific type of biological information, cognitive information. Intelligence is a specific quality of the process of thinking as an expression based on the neurophysiological mechanism of prediction. Nowadays, people more and more often speak about the anthropological, axiological crisis, modification and transformation of human nature, the creation of biological hybrids that compete with natural ones. It will hardly be possible to formalize the complexities of the human brain and mind into digital code in artificial intelligence.

Exposure to an insecticide formulation alters chemosensory orientation, but not floral scent detection, in buff-tailed bumblebees (Bombus terrestris)

Although pesticide-free techniques have been developed in agriculture, pesticides are still routinely used against weeds, pests, and pathogens worldwide. These agrochemicals pollute the environment and can negatively impact human health, biodiversity and ecosystem services. Acetamiprid, an approved neonicotinoid pesticide in the EU, may exert sub-lethal effects on pollinators and other organisms. However, our knowledge on the scope and severity of such effects is still incomplete. Our experiments focused on the effects of the insecticide formulation Mospilan (active ingredient: 20% acetamiprid) on the peripheral olfactory detection of a synthetic floral blend and foraging behaviour of buff-tailed bumblebee (Bombus terrestris) workers. We found that the applied treatment did not affect the antennal detection of the floral blend; however, it induced alterations in their foraging behaviour. Pesticide-treated individuals started foraging later, and the probability of finding the floral blend was lower than that of the control bumblebees. However, exposed bumblebees found the scent source faster than the controls. These results suggest that acetamiprid-containing Mospilan may disrupt the activity and orientation of foraging bumblebees. We hypothesize that the observed effects of pesticide exposure on foraging behaviour could be mediated through neurophysiological and endocrine mechanisms. We propose that future investigations should clarify whether such sub-lethal effects can affect pollinators’ population dynamics and their ecosystem services.

Topographically selective motor inhibition under threat of pain.

Pain-related motor adaptations may be enacted predictively at the mere threat of pain, before pain occurrence. Yet, in humans, the neurophysiological mechanisms underlying motor adaptations in anticipation of pain remain poorly understood. We tracked the evolution of changes in corticospinal excitability (CSE) as healthy adults learned to anticipate the occurrence of lateralized, muscle-specific pain to the upper limb. Using a Pavlovian threat conditioning task, different visual stimuli predicted pain to the right or left forearm (experiment 1) or hand (experiment 2). During stimuli presentation before pain occurrence, single-pulse transcranial magnetic stimulation was applied over the left primary motor cortex to probe CSE and elicit motor evoked potentials from target right forearm and hand muscles. The correlation between participants' trait anxiety and CSE was also assessed. Results showed that threat of pain triggered corticospinal inhibition specifically in the limb where pain was expected. In addition, corticospinal inhibition was modulated relative to the threatened muscle, with threat of pain to the forearm inhibiting the forearm and hand muscles, whereas threat of pain to the hand inhibited the hand muscle only. Finally, stronger corticospinal inhibition correlated with greater trait anxiety. These results advance the mechanistic understanding of pain processes showing that pain-related motor adaptations are enacted at the mere threat of pain, as sets of anticipatory, topographically organized motor changes that are associated with the expected pain and are shaped by individual anxiety levels. Including such anticipatory motor changes into models of pain may lead to new treatments for pain-related disorders.

Effects of action observation therapy for gait training in stroke: a scoping review

Action observation therapy (AOT) is a rehabilitation approach integrating sensory perception of motor skills among stroke survivors. This review article aims to investigate the effectiveness of AOT for gait training among comparative studies in stroke rehabilitation. We searched through MEDLINE, Scopus, and Google Scholar using the following subsets of terms: 'stroke' AND 'gait' AND 'action observation.' Randomised controlled trials (RCTs) and non-RCT studies focusing on AOT for gait training in stroke patients were included. Eleven RCTs and one non-RCT study met the inclusion criteria and were included for analysis. Data were extracted on sample size, inclusion criteria, type of intervention, functional outcome measures, gait parameters, and intervention effectiveness. Overall, AOT demonstrated positive results as an adjunctive intervention for improving gait properties among stroke individuals. The review highlighted its neurophysiological mechanisms and benefits in stroke rehabilitation. AOT shows promise as a beneficial adjunctive intervention for improving gait properties among stroke individuals. Further research is warranted to explore its optimal implementation and long-term effects in stroke rehabilitation.

Research progress on electromyographic methods for sustained low-intensity muscle fatigue detection

Sustained low-intensity muscle fatigue (SULMF) refers to the phenomenon that skeletal muscle continues to contract at less than 10% of maximum voluntary contraction during work activities, resulting in decreased muscle contractile function, which is one of the main causes of occupational neck, shoulder, waist and back discomfort and pain symptoms. Although surface electromyography is a key physiological technique for assessing the efficiency of neuromuscular activity, its effectiveness in objectively detecting SULMF remains controversial. Therefore, this paper describes the neurophysiological mechanism and related hypotheses of SULMF, and reviews the research progress of electromyography detection indicators and detection methods of SULMF, which is of great significance for the early prevention and accurate detection of work-related musculoskeletal disorders.

Does combining oro-facial manual therapy with bruxism neuroscience education affect pain and function in cases of awake bruxism? A pilot study.

Although awake bruxism is associated with temporomandibular disorder (TMD) as well as head and neck pain, the effects of physical therapy and bruxism education to address these factors have not been investigated. The aim of this study was to evaluate the effects of oro-facial manual therapy and bruxism neuroscience education (BNE) on awake bruxism over a 3-week period with an open-ended follow-up questionnaire after 3 months. Subjects (n = 28) were randomly allocated to one of two groups, an intervention group and a control group. Data regarding disability, function and pain were collected pre- and post-assessment, with all measures administered in a single-blind fashion. Participants in both groups received six treatment sessions during this period. In addition to manual therapy, participants were provided with information on the neurophysiological mechanisms of bruxism and contributing factors. Individual behavioural guidelines and daily exercises were determined in consultation with the therapist. An introduction to a bruxism specific app (Brux.App) was also provided, which all participants used as an adjunct to their treatment. The intervention group demonstrated notable improvement as indicated by their scores in the Neck Disability Index (NDI) (p = .008), Pain Disability Index (PDI) (p = .007) and Jaw Disability List (JDL) (p = .03). Furthermore, clinical assessments of the temporomandibular joint (TMJ) revealed a significant progress in terms of mouth opening (p = .03) and lateral jaw movement (laterotrusion) (p = .03). The mechanical pain threshold (PTT) of both the masseter (p = .02) and temporalis muscle (p = .05) also showed significant improvement. At 3-month follow-up, the questionnaire revealed that the majority of the intervention group (13/15, 87%) reported a benefit from the treatment. The reduction in pain and disability together with improvement in function and increased coping suggest a potential modification of awake bruxism through specialised musculoskeletal intervention and BNE tailored to the individual patient.

Efficacy and underlying mechanisms of three-circle post standing qigong on insomnia in college students: a four-arm, double-blind, randomized controlled trial protocol

BackgroundInsomnia is common in college students, but its impact on health and wellbeing is often neglected. Enhancing sleep quality through targeted interventions could improve overall health and reduce the risk of consequent co-morbidities and mental health problems. Qigong exercises have been shown to significantly improve sleep quality and relieve insomnia. Three-circle Post Standing (TCPS) can help integrate body, breath, and mind, a fundamental principle of Qigong that promotes holistic wellbeing. In this clinical trial, we aim to (1) evaluate the feasibility, safety, and therapeutic efficacy of administering TCPS to improve sleep quality and quality of life in college students with insomnia; (2) explore the neurophysiological mechanisms underlying the mind adjustments mediated by TCPS in insomnia; (3) investigate body and breath pathophysiology mediated by TCPS in insomnia; and (4) assess the long-term efficacy of TCPS in terms of sleep quality and quality of life.MethodsThis will be a prospective, parallel, four-arm, double-blind randomized controlled trial to investigate the effects and underlying mechanisms of TCPS on college students with insomnia. One hundred college students meeting diagnostic criteria for insomnia will be randomly assigned to receive either 14 weeks of standardized TCPS training (two weeks of centralized training followed by 12 weeks of supervised training) or sham-control Post Standing training. Efficacy outcomes including sleep quality, quality of life, neurophysiological assessments, plantar pressure, biomechanical balance, and physical measures will be collected at baseline, eight weeks (mid-point of supervised training), and 14 weeks (end of supervised training). Sleep quality and quality of life will also be evaluated during the four- and eight-week follow-up.DiscussionThis trial will be an important milestone in the development of new therapeutic approaches for insomnia and should be easily implementable by college students with insomnia. The neuro- and pathophysiological assessments will provide new insights into the mechanisms underlying TCPS.Clinical trial registrationThis trial has been registered in the China Clinical Trials Registry (registration number: ChiCTR2400080763).

Disrupted dynamic brain functional connectivity in male cocaine use disorder: Hyperconnectivity, strongly-connected state tendency, and links to impulsivity and borderline traits

Cocaine use is a major public health problem with serious negative consequences at both the individual and societal levels. Cocaine use disorder (CUD) is associated with cognitive and emotional impairments, often manifesting as alterations in brain functional connectivity (FC). This study employed resting-state functional magnetic resonance imaging (rs-fMRI) to examine dynamic FC in 38 male participants with CUD and 31 matched healthy controls. Using group spatial independent component analysis (group ICA) combined with sliding window approach, we identified two recurring distinct connectivity states: the strongly-connected state (state 1) and weakly-connected state (state 2). CUD patients exhibited significant increased mean dwell and fraction time in state 1, and increased transitions from state 2 to state 1, demonstrated significant strongly-connected state tendency. Our analysis revealed abnormal FC patterns that are state-dependent and state-shared in CUD patients. This study observed hyperconnectivity within the default mode network (DMN) and between DMN and other networks, which varied depending on the state. Furthermore, after adjustment for multiple comparisons, we found significant correlations between these altered dynamic FCs and clinical measures of impulsivity and borderline personality disorder. The disrupted FC and repetitive effects of precuneus and angular gyrus across correlations suggested that they might be the important hub of neural circuits related behaviorally and mentally in CUD. In summary, our study highlighted the potential of these disrupted FC as neuroimaging biomarkers and therapeutic targets, and provided new insights into the understanding of the neurophysiologic mechanisms of CUD.

Neurophysiological and Vascular Mechanisms of Action of Serotoninergic Drugs for Abortive Migraine Treatment

Neurophysiological and Vascular Mechanisms of Action of Serotoninergic Drugs for Abortive Migraine Treatment

Cortical responses to looming sources are explained away by the auditory periphery

A wealth of behavioral evidence indicate that sounds with increasing intensity (i.e. appear to be looming towards the listener) are processed with increased attentional and physiological resources compared to receding sounds. However, the neurophysiological mechanism responsible for such cognitive amplification remains elusive. Here, we show that the large differences seen between cortical responses to looming and receding sounds are in fact almost entirely explained away by nonlinear encoding at the level of the auditory periphery. We collected electroencephalography (EEG) data during an oddball paradigm to elicit mismatch negativity (MMN) and others Event Related Potentials (EPRs), in response to deviant stimuli with both dynamic (looming and receding) and constant level (flat) differences to the standard in the same participants. We then combined a computational model of the auditory periphery with generative EEG methods (temporal response functions, TRFs) to model the single-participant ERPs responses to flat deviants, and used them to predict the effect of the same mechanism on looming and receding stimuli. The flat model explained 45% variance of the looming response, and 33% of the receding response. This provide striking evidence that difference wave responses to looming and receding sounds result from the same cortical mechanism that generate responses to constant-level deviants: all such differences are the sole consequence of their particular physical morphology getting amplified and integrated by peripheral auditory mechanisms. Thus, not all effects seen cortically proceed from top-down modulations by high-level decision variables, but can rather be performed early and efficiently by feed-forward peripheral mechanisms that evolved precisely to sparing subsequent networks with the necessity to implement such mechanisms.

Corticomotor pathway function and recovery after stroke: a look back and a way forward.

Stroke is a leading cause of adult disability that results in motor deficits and reduced independence. Regaining independence relies on motor recovery, particularly regaining function of the hand and arm. This review presents evidence from human studies that have used transcranial magnetic stimulation (TMS) to identify neurophysiological mechanisms underlying upper limb motor recovery early after stroke. TMS studies undertaken at the subacute stage after stroke have identified several neurophysiological factors that can drive motor impairment, including membrane excitability, the recruitment of corticomotor neurons, and glutamatergic and GABAergic neurotransmission. However, the inherent variability and subsequent poor reliability of measures derived from motor evoked potentials (MEPs) limit the use of TMS for prognosis at the individual patient level. Currently, prediction tools that provide the most accurate information about upper limb motor outcomes for individual patients early after stroke combine clinical measures with a simple neurophysiological biomarker based on MEP presence or absence, i.e. MEP status. Here, we propose a new compositional framework to examine MEPs across several upper limb muscles within a threshold matrix. The matrix can provide a more comprehensive view of corticomotor function and recovery after stroke by quantifying the evolution of subthreshold and suprathreshold MEPs through compositional analyses. Our contention is that subthreshold responses might be the most sensitive to reduced output of corticomotor neurons, desynchronized firing of the remaining neurons, and myelination processes that occur early after stroke. Quantifying subthreshold responses might provide new insights into post-stroke neurophysiology and improve the accuracy of prediction of upper limb motor outcomes.

Exploring the immediate and short-term effect of lumbar spinal manipulation on pressure pain threshold: a randomized controlled trial of healthy participants

BackgroundLumbar spinal manipulative therapy (SMT) is a common intervention used to treat low back pain (LBP); however, the exact neurophysiological mechanisms of SMT reducing pain measured through pain pressure threshold (PPT) have not been fully explored beyond an immediate timeframe (e.g., immediately or five-minutes following) referencing a control group. Therefore, the purpose of this study was to investigate the neurophysiological effects of lumbar SMT compared to deactivated ultrasound using PPT immediately following and 30-minutes following SMT.MethodsA longitudinal, randomized controlled trial design was conducted between September to October 2023. Fifty-five participants were randomized into a control group of deactivated ultrasound (n = 29) or treatment group of right sidelying lumbar SMT (n = 26). PPT, recorded at the right posterior superior iliac spine (PSIS), was documented for each participant in each group prior to intervention, immediately, and 30-minutes after. A repeated measures ANOVA, with a post-hoc Bonferroni adjustment, was used to assess within-group and between-group differences in PPT. The significance level was set at a < 0.05 a priori.ResultsStatistically significant differences were found between the deactivated ultrasound and lumbar SMT groups immediately (p = .05) and 30-minutes (p = .02) following intervention. A significant difference in the lumbar SMT group was identified from baseline to immediately following (p < .001) and 30-minutes following (p < .001), but no differences between immediately following and 30-minutes following intervention (p = .10). The deactivated ultrasound group demonstrated a difference between baseline and immediately after intervention with a reduced PPT (p = .003), but no significant difference was found from baseline to 30-minutes (p = .11) or immediately after intervention to 30-minutes (p = 1.0).ConclusionA right sidelying lumbar manipulation increased PPT at the right PSIS immediately after that lasted to 30-minutes when compared to a deactivated ultrasound control group. Future studies should further explore beyond the immediate and short-term neurophysiological effects of lumbar SMT to validate these findings.Trial RegistrationThis study was retrospectively registered on 4 December 2023 in ClinicalTrials (database registration number NCT06156605).

On Persons, Populations, and Causal Mechanisms Some Critical Reflections on Lundh (2023).

While agreeing with Lundh (2023) on many of his major points, this article also questions the notion of a 'population psychology.' It is argued that the knowledge produced in population-level studies, whether correlational, experimental, or mixed, is inherently demographic in nature. Concerning individual-level studies, agreement with Lundh (2023) is expressed concerning the need to distinguish between a conception of individuals as mere depositories of neurophysiological mechanisms on the one hand, and as active, purposeful agents on the other. It is suggested that the conceptual framework called 'critical personalism' would well serve a scientific psychology committed to the latter view.