Potential of a New, Flexible Electrode sEMG System in Detecting Electromyographic Activation in Low Back Muscles during Clinical Tests: A Pilot Study on Wearables for Pain Management.

BACKGROUND: While low back pain (LBP) is the leading cause of disability worldwide, its clinical objective assessment is currently limited. Part of this syndrome arises from the abnormal sensorimotor control of back muscles, involving increased muscle fatigability (i.e., assessed with the Biering-Sorensen test) and abnormal muscle activation patterns (i.e., the flexion-extension test). Surface electromyography (sEMG) provides objective measures of muscle fatigue development (median frequency drop, MDF) and activation patterns (RMS amplitude change). This study therefore assessed the sensitivity and validity of a novel and flexible sEMG system (NSS) based on PEVA electrodes and potentially embeddable in textiles, as a tool for objective clinical LBP assessment. METHODS: Twelve participants wearing NSS and a commercial laboratory sEMG system (CSS) performed two clinical tests used in LBP assessment (Biering-Sorensen and flexion-extension). Erector spinae muscle activity was recorded at T12-L1 and L4-L5. RESULTS: NSS showed sensitivity to sEMG changes associated with fatigue development and muscle activations during flexion-extension movements (p < 0.05) that were similar to CSS (p > 0.05). Raw signals showed moderate cross-correlations (MDF: 0.60-0.68; RMS: 0.53-0.62). Adding conductive gel to the PEVA electrodes did not influence sEMG signal interpretation (p > 0.05). CONCLUSIONS: This novel sEMG system is promising for assessing electrophysiological indicators of LBP during clinical tests.

Neuromechanical Responses to Spinal Manipulation and Mobilization: A Crossover Randomized Clinical Trial.

OBJECTIVE: The purpose of this study was to compare the immediate effect of spinal manipulation (SMa) and spinal mobilization (SMo) on muscular responses, spinal stiffness, and segmental spinal pressure evoked pain in a population of participants with chronic middle back pain (MBP). METHODS: In a crossover randomized trial, 2 experienced chiropractors assessed whether volunteers were eligible for the protocol according to a list of specific inclusion and exclusion criteria. Individuals with MBP participated in 2 experimental sessions within 72 hours. During the first session, participants randomly received a SMa or SMo delivered by an apparatus using a servolinear motor. During the second session, the other modality was delivered. Spinal stiffness and pressure-provoked pain intensity outcomes were assessed before and after each therapy, and muscular responses were recorded during the treatment using surface electromyographic sensors. Signed-rank Wilcoxon tests for muscular responses and generalized model for repeated measure for spinal stiffness and pressure-provoked pain were used for statistical analyses. RESULTS: Among the 32 potential participants, 26 (mean age 29.9 [±9.14], 15 women) completed both sessions. Between-group differences were observed for the muscular response amplitude (P < .001), and indeed the normalized RMS muscular response was found to be higher during SMa than SMo. Similar results were observed for pressure-provoked pain intensity at the level of therapeutic modality application (P = .002) as a higher decrease in pain was found after SMa (47.9 [±22.8] to 36.6 [±23.7]) compared with SMo (47.2 [±23.2] to 45.5 [±24.3]). No between-group differences were found for spinal stiffness change, nor for terminal (P = .08) and global spinal stiffness (P = .06). CONCLUSION: In a controlled environment, spinal manipulation and mobilization generated different muscle responses and had different immediate effects on pressure-provoked pain intensity for participants with MBP.

Attitudes towards chiropractic: a repeated cross-sectional survey of Canadian family physicians.

BACKGROUND: Many primary care patients receive both medical and chiropractic care; however, interprofessional relations between physicians and chiropractors are often suboptimal which may adversely affect care of shared patients. We surveyed Canadian family physicians in 2010 to explore their attitudes towards chiropractic and re-administered the same survey a decade later to explore for changes in attitudes. METHODS: A 50-item survey administered to a random sample of Canadian family physicians in 2010, and again in 2019, that inquired about demographic variables, knowledge and use of chiropractic. Imbedded in our survey was a 20-item chiropractic attitude questionnaire (CAQ); scores could range from 0 to 80 with higher scores indicating more positive attitudes toward chiropractic. We constructed a multivariable regression model to explore factors associated with CAQ scores. RESULTS: Among eligible physicians, 251 of 685 in 2010 (37% response rate) and 162 of 2429 in 2019 (7% response rate) provided a completed survey. Approximately half of respondents (48%) endorsed a positive impression of chiropractic, 27% were uncertain, and 25% held negative views. Most respondents (72%) referred at least some patients for chiropractic care, mainly due to patient request or lack of response to medical care. Most physicians believed that chiropractors provide effective therapy for some musculoskeletal complaints (84%) and disagreed that chiropractic care was beneficial for non-musculoskeletal conditions (77%). The majority agreed that chiropractic care was a useful supplement to conventional care (65%) but most respondents (59%) also indicated that practice diversity among chiropractors presented a barrier to interprofessional collaboration. In our adjusted regression model, attitudes towards chiropractic showed trivial improvement from 2010 to 2019 (0.31 points on the 80-point CAQ; 95%CI 0.001 to 0.62). More negative attitudes were associated with older age (- 1.55 points for each 10-year increment from age 28; 95%CI - 2.67 to - 0.44), belief that adverse events are common with chiropractic care (- 1.41 points; 95% CI - 2.59 to - 0.23) and reported use of the research literature (- 6.04 points; 95% CI - 8.47 to - 3.61) or medical school (- 5.03 points; 95% CI - 7.89 to - 2.18) as sources of knowledge on chiropractic. More positive attitudes were associated with endorsing a relationship with a specific chiropractor (5.24 points; 95% CI 2.85 to 7.64), family and friends (4.06 points; 95% CI 1.53 to 6.60), or personal treatment experience (4.63 points; 95% CI 2.14 to 7.11) as sources of information regarding chiropractic. CONCLUSIONS: Although generally positive, Canadian family physicians' attitudes towards chiropractic are diverse, and most physicians felt that practice diversity among chiropractors was a barrier to interprofessional collaboration.

Effects of spinal manipulative therapy biomechanical parameters on clinical and biomechanical outcomes of participants with chronic thoracic pain: a randomized controlled experimental trial.

BACKGROUND: Spinal manipulative therapy (SMT) includes biomechanical parameters that vary between clinicians, but for which the influence on the therapy clinical effects is unknown. This parallel-randomized controlled trial aimed to investigate the effect of SMT biomechanical parameters on the outcomes of participants with chronic thoracic pain (CTP) following three treatment sessions (follow-up at one week). METHODS: Adults reporting CTP (pain within the evaluated region [T6 to T8] for ≥3 months) were asked to participate in a four-session trial. At the first session, participants were randomly assigned to one of three experimental groups (different SMT doses) or the control group (no SMT). During the first three sessions, one SMT was executed at T7 for the experimental groups, while a 5-min rest was provided to the control group. SMT were delivered through an apparatus using a servo-controlled linear actuator motor and doses consisted of peak forces, impulse durations, and rates of force application set at 135 N, 125 ms and 920 N/s (group 1), at 250 N, 125 ms and 1840 N/s (group 2), and at 250 N, 250 ms, 920 N/s (group 3). Disability and pain intensity were evaluated at each session (primary outcomes). Spinal stiffness was assessed before-and-after each SMT/rest and at follow-up. Tenderness and muscle activity were evaluated during each spinal stiffness trial. Improvement was evaluated at follow-up. Differences in outcomes between groups and sessions were evaluated as well as factors associated with clinical improvement. RESULTS: Eighty-one participants were recruited and 17, 20, 20 participants of the three experimental groups and 18 of the control group completed the protocol. In exception of higher pain intensity at baseline in the control group, no between-group differences were found for any of the outcomes. A decrease in pain intensity, disability, spinal stiffness, and tenderness during spinal stiffness were observed (p-values< 0.05). At follow-up, 24% of participants were classified as 'improved'. Predictors of improvement were a greater decrease in pain intensity and in tenderness (p-values< 0.05). CONCLUSIONS: In an experimental setting, the delivery of a SMT does not lead to significantly different outcomes in participants with CTP than a control condition (spinal stiffness assessment). Studies are still required to explore the mechanisms underlying SMT effects. TRIAL REGISTRATION: ClinicalTrials.gov NCT03063177 , registered 24 February 2017).

Clinicians' Ability to Detect a Palpable Difference in Spinal Stiffness Compared With a Mechanical Device.

OBJECTIVE: The purpose of this study was to quantify the threshold at which clinicians can detect a difference in spinal stiffness of the thoracic and lumbar spine via palpation and then determine if this detection threshold would affect a clinician's ability to identify changes in spinal stiffness as measured by an objective instrument. METHODS: In this study, the threshold at which a change in spinal stiffness was detected was quantified in 12 experienced clinicians (physical therapists and doctors of chiropractic) by changing the differential stiffness in 2 inflatable targets until the clinician could no longer identify which was stiffer. In the second part of the study, clinicians then were asked to palpate pre-identified pairs of vertebrae in an asymptomatic volunteer and to identify the stiffer of the pair (T7 and L3, T7 and L4, L3 and L4), and the biomechanical stiffness of each vertebral pair was quantified objectively by a validated instrument. RESULTS: The mean stiffness detection threshold for the clinicians was 8%. Objective measurement of the stiffness differential between vertebral pairs was 30% for T7* and L3, 20% for T7* and L4, and 10% for L3* and L4 (*denotes the stiffer of the pair). Ten of 12 clinicians correctly identified T7 as stiffer when compared with L3 and T7 as stiffer than L4. Alternatively, when the differential vertebral pair stiffness was similar to the stiffness detection threshold (~8%), clinicians were less successful in identifying the stiffer vertebra of the pair; 4 of 12 clinicians correctly identified L3 as being stiffer compared with L4. CONCLUSION: These results suggest that the physiological limits of human palpation may limit the ability of clinicians to identify small alterations in spine stiffness.

Prevalence and practice characteristics of urban and rural or remote Australian chiropractors: Analysis of a nationally representative sample of 1830 chiropractors.

OBJECTIVE: To determine the prevalence and clinical management characteristics of chiropractors practising in urban and rural or remote Australia. DESIGN: A cross-sectional analysis of the Australian Chiropractic Research Network project data. SETTING: Nationally representative sample of registered chiropractors practising in Australia. PARTICIPANTS: Chiropractors who participated in the Australian Chiropractic Research Network project and answered a question about practising in urban or rural or remote areas in the practitioner questionnaire. MAIN OUTCOME MEASURE: The demographics, practice characteristics and clinical management of chiropractors. RESULTS: The majority of chiropractors indicated that they practise in urban areas only, while 22.8% (n = 435) practice in rural or remote areas only and 4.0% (n = 77) practice in both urban and rural or remote areas. Statistically significant predictors of chiropractors who practice in rural or remote areas, as compared to urban areas, included more patient visits per week, practising in more than one location, no imaging facilities on site, often treating degenerative spinal conditions or migraine, often treating people aged over 65 years, frequently treating Aboriginal and Torres Strait Islander people and frequently using biomechanical pelvic blocking or the sacro-occipital technique. CONCLUSION: A substantial number of chiropractors practice in rural or remote Australia and these rural or remote-based chiropractors are more likely to treat a wide range of musculoskeletal cases and include an Indigenously diverse group of patients than their urban-located colleagues. Unique practice challenges for rural or remote chiropractors include a higher workload and a lack of diagnostic tools. Chiropractors should be acknowledged and considered within rural or remote health care policy and service provision.

Vertebral Displacements and Muscle Activity During Manual Therapy: Distinct Behaviors Between Spinal Manipulation and Mobilization.

OBJECTIVE: The purpose of this study was to compare vertebral displacements (absolute and relative) and muscle responses induced by spinal manipulative therapy of short (spinal manipulation) and long (spinal mobilization) impulse duration. METHODS: Twenty-five healthy adults (without thoracic pain) were recruited for this crossover study. Six spinal manipulative therapies (255 N peak force) of different impulse durations (100, 125, 200, 500, 1000, and 1500 ms) were delivered to each participant's T7 transverse process using a mechanical device. Impulse duration effect on the vertebral displacement (absolute displacement of T6, T7, and T8 and relative displacement between T7 and T6 and between T7 and T8) and the thoracic muscle response (surface electromyography) were assessed using mixed-model analyses of variance and predefined linear trend analyses. RESULTS: Results showed a linear increase in the absolute vertebral displacement for T8 (P = .002) and a linear decrease in the T7/T6 and T7/T8 relative displacement (P < .0001) when impulse duration was increased. The data of 24 participants were available for electromyography analysis. A significant main effect of impulse duration on surface electromyography response was observed (P < .0001, ƞp2=0.43). Planned comparisons for a linear trend between these variables revealed a negative relationship (P < .0001). Only 13 of the 24 participants with available data presented a muscle response at every impulse duration. CONCLUSION: These results support the assumption that spinal manipulation and spinal mobilization might operate under distinct mechanisms.

Correlations Between Individuals' Characteristics and Spinal Stiffness in Individuals With and Without Back Pain: A Combined Analysis of Multiple Data Sets.

OBJECTIVE: The purpose of this study was to describe the correlations between individual characteristics and spinal stiffness as measured with different spinal stiffness measurement devices in individuals with and without back pain. METHODS: A secondary analysis of 3 adult data sets obtained using 3 different devices, in 2 spinal regions, from a total of 5 separate cross-sectional studies was conducted. Differences in spinal stiffness between men and women and in the strength of correlations among spinal stiffness and age and anthropometric characteristics were evaluated using either the t test for independent samples, Pearson's correlation coefficient, or Kendall's τ rank correlation coefficient. RESULTS: As expected, results varied between data sets; however, few factors had consistent correlations. Specifically, spinal stiffness was significantly lower in women than men in all 3 data sets. Height was positively correlated with spinal stiffness across all data sets. Although weight was correlated with thoracic stiffness, its correlation with lumbar stiffness varied. In 2 data sets, body mass index was inversely associated with lumbar spinal stiffness, whereas results from the thoracic spine region revealed a positive correlation. The results for 1 data set suggest that physiological measurement evaluating body weight distribution may also affect spinal stiffness; however, the specific correlation remains unclear. CONCLUSION: Despite data set differences, significant correlations were observed, indicating that participants' characteristics appear to affect spinal stiffness measurement.

Spinal Manipulative Therapy and Other Conservative Treatments for Low Back Pain: A Guideline From the Canadian Chiropractic Guideline Initiative.

OBJECTIVE: The objective of this study was to develop a clinical practice guideline on the management of acute and chronic low back pain (LBP) in adults. The aim was to develop a guideline to provide best practice recommendations on the initial assessment and monitoring of people with low back pain and address the use of spinal manipulation therapy (SMT) compared with other commonly used conservative treatments. METHODS: The topic areas were chosen based on an Agency for Healthcare Research and Quality comparative effectiveness review, specific to spinal manipulation as a nonpharmacological intervention. The panel updated the search strategies in Medline. We assessed admissible systematic reviews and randomized controlled trials for each question using A Measurement Tool to Assess Systematic Reviews and Cochrane Back Review Group criteria. Evidence profiles were used to summarize judgments of the evidence quality and link recommendations to the supporting evidence. Using the Evidence to Decision Framework, the guideline panel determined the certainty of evidence and strength of the recommendations. Consensus was achieved using a modified Delphi technique. The guideline was peer reviewed by an 8-member multidisciplinary external committee. RESULTS: For patients with acute (0-3 months) back pain, we suggest offering advice (posture, staying active), reassurance, education and self-management strategies in addition to SMT, usual medical care when deemed beneficial, or a combination of SMT and usual medical care to improve pain and disability. For patients with chronic (>3 months) back pain, we suggest offering advice and education, SMT or SMT as part of a multimodal therapy (exercise, myofascial therapy or usual medical care when deemed beneficial). For patients with chronic back-related leg pain, we suggest offering advice and education along with SMT and home exercise (positioning and stabilization exercises). CONCLUSIONS: A multimodal approach including SMT, other commonly used active interventions, self-management advice, and exercise is an effective treatment strategy for acute and chronic back pain, with or without leg pain.

Neuromechanical response to spinal manipulation therapy: effects of a constant rate of force application.

BACKGROUND: Neuromechanical responses to spinal manipulation therapy (SMT) have been shown to be modulated through the variation of SMT biomechanical parameters: peak force, time to peak force, and preload force. Although rate of force application was modulated by the variation of these parameters, the assumption that neuromuscular responses are modulated by the rate of force application remains to be confirmed. Therefore, the purpose of the present study was to evaluate the effect of a constant rate of force application in neuromechanical responses to SMT in healthy adults. METHODS: Four SMT force-time profiles presenting different time to peak force and peak force, but with a constant rate of force application were applied on 25 healthy participants' T7 transverse processes. Muscular responses were recorded through surface electromyography electrodes (T6 and T8 levels), while vertebral displacements were assessed through pasted kinematic markers on T6 to T8 spinous processes. Effects of SMT force-time profiles on neuromechanical responses were assessed using repeated-measures ANOVAs. RESULTS: There was no main effect of SMT force-time profile modulation on muscular responses (ps > .05) except for the left T8 (F (3, 72) = 3.23, p = .03) and left T6 (F (3, 72) = 2.94, p = .04). Muscular responses were significantly lower for the lowest peak force condition than the highest (for T8) or second highest (for T6). Analysis showed that increasing the SMT peak force (and concomitantly time to peak force) led to a significant vertebral displacement increase for the contacted vertebra (F T7 (1, 17) = 354.80, p < .001) and both adjacent vertebras (F T6 (1, 12) = 104.71, p < .001 and F T8 (1, 19) = 468.68, p < .001). CONCLUSION: This study showed that peak force modulation using constant rate of force application leads to similar neuromuscular responses. Coupled with previous investigations of SMT peak force and duration effects, the results suggest that neuromuscular responses to SMT are mostly influenced by the rate of force application, while peak force modulation yields changes in the vertebral displacement. Rate of force application should therefore be defined in future studies. Clinical implications of various SMT dosages in patients with spine related pain should also be investigated. TRIAL REGISTRATION: ClinicalTrials.gov NCT02550132 . Registered 8 September 2015.

Systematic Augmented Feedback and Dependency in Spinal Manipulation Learning: a Randomized Comparative Study.

OBJECTIVE: The purpose of the study was to evaluate if systematic augmented feedback during short sessions of spinal manipulation (SM) training creates a dependency compared with short training session characterized by progressive withdrawal of augmented feedback. METHODS: Forty fourth- and fifth-year chiropractic students enrolled in a 5-year chiropractic program were randomized into 2 groups. The 2 groups performed the same number of SM with a 300-N peak force target on an instrumented device. Baseline assessment consisted of 10 trials without feedback. Three training blocks of 10 SMs were then performed with visual and verbal feedback. For the control group, feedback was always provided. For the experimental group, augmented feedback was provided for each trial of the first training block, 50% of the second block, and 20% of the last training block. A postintervention assessment of 10 trials without feedback was performed, and a retention assessment was conducted 20 minutes later. RESULTS: No group main effect was found on biomechanical parameters and error variables. A main effect of learning for the absolute error was observed, suggesting that short sessions of feedback training improve participants' accuracy. CONCLUSION: The results of the study suggest that feedback scheduling does not influence SM motor performance and learning in clinically experienced students.

The Treatment of Neck Pain-Associated Disorders and Whiplash-Associated Disorders: A Clinical Practice Guideline.

OBJECTIVE: The objective was to develop a clinical practice guideline on the management of neck pain-associated disorders (NADs) and whiplash-associated disorders (WADs). This guideline replaces 2 prior chiropractic guidelines on NADs and WADs. METHODS: Pertinent systematic reviews on 6 topic areas (education, multimodal care, exercise, work disability, manual therapy, passive modalities) were assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR) and data extracted from admissible randomized controlled trials. We incorporated risk of bias scores in the Grading of Recommendations Assessment, Development, and Evaluation. Evidence profiles were used to summarize judgments of the evidence quality, detail relative and absolute effects, and link recommendations to the supporting evidence. The guideline panel considered the balance of desirable and undesirable consequences. Consensus was achieved using a modified Delphi. The guideline was peer reviewed by a 10-member multidisciplinary (medical and chiropractic) external committee. RESULTS: For recent-onset (0-3 months) neck pain, we suggest offering multimodal care; manipulation or mobilization; range-of-motion home exercise, or multimodal manual therapy (for grades I-II NAD); supervised graded strengthening exercise (grade III NAD); and multimodal care (grade III WAD). For persistent (>3 months) neck pain, we suggest offering multimodal care or stress self-management; manipulation with soft tissue therapy; high-dose massage; supervised group exercise; supervised yoga; supervised strengthening exercises or home exercises (grades I-II NAD); multimodal care or practitioner's advice (grades I-III NAD); and supervised exercise with advice or advice alone (grades I-II WAD). For workers with persistent neck and shoulder pain, evidence supports mixed supervised and unsupervised high-intensity strength training or advice alone (grades I-III NAD). CONCLUSIONS: A multimodal approach including manual therapy, self-management advice, and exercise is an effective treatment strategy for both recent-onset and persistent neck pain.

Chronic low back pain clinical outcomes present higher associations with the STarT Back Screening Tool than with physiologic measures: a 12-month cohort study.

BACKGROUND: Stratification strategies based on identifying patient's prognosis in order to guide patient care constitute one of the most prominent and recent approach in low back pain research. The STarT Back Screening Tool (SBST) although promising, has not been studied in patients with chronic low back pain (cLBP). Considering how challenging it is to translate research into practice, the value of integrating a new tool should be thoroughly assessed. The purpose was therefore to assess associations between the short- and long-terms clinical status and two types of variables, physiologic measures and the SBST, in participants with cLBP. The ability of both types of variables to discriminate between participants with and without higher levels of disability, pain, fear of movement and patient's global impression of change was also investigated. METHODS: Fifty-three volunteers with cLBP participated in an initial evaluation and follow-ups at 2-, 4-, 6- and 12-month. Physiologic measures (maximal voluntary contraction, maximal endurance and muscle activity evaluated during prone and lateral isometric tasks) and the SBST were assessed at baseline. Disability (Oswestry Disability Index, ODI), pain intensity (101-point Numerical Rating Scale, NRS), fear of movement (Tampa Scale for Kinesiophobia, TSK) and patient's global impression of change (7-point scale, PGIC) were evaluated at baseline and at each follow-up. Aside the use of correlation analyses to assess potential associations; ROC curves were performed to evaluate the discriminative ability of physiologic measures and the SBST. RESULTS: The SBST allowed for the identification of participants presenting higher levels of disability (ODI ≥24 %), pain (NRS ≥37 %) or fear of movement (TSK ≥41/68) over a 12-month period (AUC = 0.71 to 0.84, ps < 0.05). The SBST score was also correlated with disability at each follow-up (τ = 0.22 to 0.33, ps < 0.05) and with pain intensity and fear of movement at follow-ups. Among physiologic measures, only maximal voluntary contraction was correlated to disability, pain intensity or fear of movement during the follow-up (|τ| = 0.26 to 0.32, ps < 0.05) and none was able to identify participants presenting higher levels of outcomes (AUC ps > 0.05). CONCLUSION: Physiologic measures obtained during prone and lateral tests have limited associations with the clinical status over a 12-month period in patients with nonspecific chronic low back pain. On the other hand, the STarT Back Screening Tool is useful for the identification of patients who will present higher levels of disability, pain intensity and fear of movement over a year. TRIAL REGISTRATION: Clinicaltrials.gov NCT02226692.

Neuromechanical responses after biofeedback training in participants with chronic low back pain: an experimental cohort study.

OBJECTIVE: The objective of this study was to evaluate changes in neuromechanical responses and clinical outcomes in chronic low back pain participants after 4 sessions of biofeedback training. METHODS: Twenty-one participants took part in an electromyography biofeedback 4-session training program aimed at reducing lumbar paraspinal muscle activity during full trunk flexion. The sessions consisted of ~46 trunk flexion-extension divided into 5 blocks. The effects of training blocks and sessions on lumbar flexion-relaxation ratio and lumbopelvic ranges of motion were assessed. Changes in disability (Oswestry Disability Index), pain intensity (numerical rating scale), and fear of movement (Tampa Scale for Kinesiophobia) were also evaluated. RESULTS: Analyses of variance revealed a significant block effect for which an increase in the flexion-relaxation ratio and the lumbar range of motion between block 1 and the other blocks for sessions 1 and 2 (P < .0001) was observed. However, no significant session or interaction effect was observed. Among clinical outcomes, only fear of movement significantly decreased between the baseline (mean [SD], 33.05 [7.18]) and the fourth session (29.80 [9.88]) (P = .02). There was no significant correlation between clinical outcomes and neuromechanical variables. CONCLUSION: Biofeedback training led to decreases in lumbar paraspinal muscle activity in full trunk flexion and increases in lumbopelvic range of motion in participants with chronic nonspecific low back pain. Although the neuromechanical changes were mostly observed at the early stage of the program, the presence of a decrease in the fear of movement suggests that the participants' initially limited ROMs may have been modulated by fear avoidance behaviors.

Trunk motor variability in patients with non-specific chronic low back pain.

PURPOSE: To identify and characterize trunk neuromuscular adaptations during muscle fatigue in patients with chronic low back pain (LBP) and healthy participants. METHODS: Forty-six patients with non-specific chronic LBP and 23 healthy controls were asked to perform a trunk muscles fatigue protocol. Surface electromyography was recorded using two adhesive matrix of 64 electrodes applied bilaterally over the erector spinae. Pain score, kinesiophobia and physical disability were analyzed through different questionnaires. To characterize motor variability, dispersion of muscular activity center of gravity was computed. Motor variability between groups was compared using repeated-measures analyses of variance. RESULTS: Score of disability and kinesiophobia were significantly higher in patients with LBP. Results indicated a significant group effect characterized by an increased motor variability in the healthy group through the entire fatigue task on the left (p = 0.003) and right side (p = 0.048). Interestingly, increasing muscle fatigue led to increased motor variability in both groups (on both sides (p < 0.001) but with a greater increase in the healthy group. CONCLUSION: Muscle recruitment is altered in patients with chronic LBP in the presence of muscle fatigue. Consequently, these patients exhibit changes in muscle recruitment pattern and intensity (lower levels of motor variability) during sustained isometric contraction that may be attributed to variation in the control of motor units within and between muscles. However, patients with LBP are able to increase their motor variability over time but with a lower increase compared to healthy participants.

The role of preload forces in spinal manipulation: experimental investigation of kinematic and electromyographic responses in healthy adults.

OBJECTIVES: Previous studies have identified preload forces and an important feature of skillful execution of spinal manipulative therapy (SMT) as performed by manual therapists (eg, doctors of chiropractic and osteopathy). It has been suggested that applying a gradual force before the thrust increases the spinal unit stiffness, minimizing displacement during the thrust. Therefore, the main objective of this study was to assess the vertebral unit biomechanical and neuromuscular responses to a graded increase of preload forces. METHODS: Twenty-three participants underwent 4 different SMT force-time profiles delivered by a servo-controlled linear actuator motor and varying in their preload forces, respectively, set to 5, 50, 95, and 140N in 1 experimental session. Kinematic markers were place on T6, T7, and T8 and electromyographic electrodes were applied over paraspinal muscles on both sides of the spine. RESULTS: Increasing preload forces led to an increase in neuromuscular responses of thoracic paraspinal muscles and vertebral segmental displacements during the preload phase of SMT. Increasing the preload force also yielded a significant decrease in sagittal vertebral displacement and paraspinal muscle activity during and immediately after the thrust phase of spinal manipulation. Changes observed during the SMT thrust phase could be explained by the proportional increase in preload force or the related changes in rate of force application. Although only healthy participants were tested in this study, preload forces may be an important parameter underlying SMT mechanism of action. Future studies should investigate the clinical implications of varying SMT dosages. CONCLUSION: The present results suggest that neuromuscular and biomechanical responses to SMT may be modulated by preload through changes in the rate of force application. Overall, the present results suggest that preload and rate of force application may be important parameters underlying SMT mechanism of action.

Assessing adverse events associated with chiropractic care in preschool pediatric population: a feasibility study.

BACKGROUND: Manual therapies are commonly used by healthcare professionals when caring for children. However, few prospective studies have evaluated their adverse events (AEs). This study aims to assess the feasibility of a pragmatic prospective study aiming to report the immediate and delayed (48-hours post-treatment) AEs associated with manual therapies in children aged 5 or younger. Preliminary data on AEs frequency are also reported. METHODS: Between July 2021 and March 2022, chiropractors were recruited through purposive sampling and via a dedicated Facebook group for Quebec chiropractors interested in pediatrics. Legal guardians of patients aged 5 or younger were invited to fill out an online information and consent form. AEs were collected using the SafetyNET reporting system, which had been previously translated by the research team. Immediate AEs were collected through a questionnaire filled out by the legal guardian immediately after the treatment, while delayed AEs were collected through a questionnaire sent by email to the legal guardian 48 h after the treatment. Feasibility was assessed qualitatively through feedback from chiropractors and quantitatively through recruitment data. RESULTS: Overall, a total of 28 chiropractors expressed interest following the Facebook publication, and 5 participated. An additional two chiropractors were enrolled through purposive sampling. In total, 80 legal guardians consented to their child's participation, and data from 73 children were included for the analysis of AEs. At least one AE was reported in 30% of children (22/73), and AEs were mainly observed immediately following the treatment (16/22). The most common AEs were irritability/crying (11 children) or fatigue/tiredness (11 children). Feasibility analysis demonstrated that regular communication between the research team and clinicians, as well as targeting clinicians who showed great interest in pediatrics, were key factors for successful research. CONCLUSION: Results suggest that it is feasible to conduct a prospective pragmatic study evaluating AEs associated with manual therapies in private practices. Direct communication with the clinicians, a strategic clinicians' recruitment plan, and the resulting administrative burden should be considered in future studies. A larger study is required to confirm the frequency of AEs reported in the current study. TRIAL REGISTRATION: ClinicalTrials.gov., NCT05409859, Registered on June 3 2022. https://clinicaltrials.gov/study/NCT05409859 .

Effect of physical activity education on shoulder girdle pain and muscle strength in participants with fibromyalgia: a pilot experimental study.

Background: In patients with fibromyalgia, exercise and education are recommended to decrease pain level and improve pain management. The latest scientific evidence recommends to focus interventions on the upper limb. The aim of this pilot study was to compare the immediate effect of physical activity education vs. a control group on pain and muscle capacity in fibromyalgia patients. Method: Fifty-six participants with fibromyalgia were randomized into an experimental group and a control group. The intervention consisted in watching a five-minute video that provided information about fibromyalgia, pain, kinesiophobia and physical activity. The control group watched a neutral five-minute video about beavers in Quebec. Following the video, participants performed a muscular fatigue task consisting of a repeated unilateral shoulder abduction task. At baseline and following the muscular fatigue task, maximal voluntary contraction (MVC) in shoulder abduction was assessed as well as pain level and pressure pain threshold (PPT) in the upper limb. Electromyographic activity was also assessed for upper trapezius and middle deltoid muscles. Two-way repeated measures analysis of variance was used to compare the MVC, PPT, and pain level before and after the muscular fatigue task between groups. Results: The experimental group showed a significantly lower increase in pain than the control group in the middle deltoid muscle (p = 0.002) when assessed by verbal pain rating scale. No significant interaction or main effect of Group and Time were observed for the pain level at the upper trapezius and elbow extensor muscles nor for any of the PPT measures. According to electromyographic data, the median frequency values indicate that neither group experienced muscle fatigue during the repeated contraction task. Conclusions: The preliminary results suggest that a short physical activity education video positively influenced middle deltoid pain following repeated abduction in participants with fibromyalgia. Electromyographic analysis showed no evidence of objective muscle fatigue, suggesting that there might be a partial disconnection between the perception of muscle fatigue and the physiological biomarkers associated with muscle fatigue.

Minimal clinical datasets for spine-related musculoskeletal disorders in primary and outpatient care settings: a scoping review.

OBJECTIVES: Effective measurement and monitoring of health status in patients with spine-related musculoskeletal (MSK) disorders are essential for providing appropriate care and improving outcomes. Minimal clinical datasets are standardized sets of key data elements and patient-centered outcomes that can be measured and recorded during routine clinical care. Our scoping review aimed to identify and map current evidence on minimal clinical datasets for measuring and monitoring health status in patients with spine-related MSK disorders in primary and outpatient healthcare settings. STUDY DESIGN AND SETTING: We followed the JBI (formerly Joanna Briggs Institute) methodology for scoping reviews. MEDLINE, CINAHL, Cochrane Library, Index to Chiropractic Literature, MANTIS, ProQuest Dissertations and Theses Global, and medRxiv preprint repository were searched from database inception to August 1, 2021. Two reviewers independently screened titles and abstracts, full-text articles, and charted the evidence. Findings were synthesized and summarized descriptively. RESULTS: After screening 5,583 citations and 301 full-text articles, 104 studies about 32 individual minimal clinical datasets were included. Most minimal clinical datasets were developed for patient populations with spine-involving inflammatory arthritis, nonspecific or degenerative spinal pain, and MSK disorders in general. The minimal clinical datasets varied substantially in terms of the author-reported time-to-complete (1-48 minutes) and the number of items (5-100 items). Fifty percent of the datasets involved healthcare professionals in their development process, and only 28% involved patients. Health domain items were most frequently linked to the components of activities and participation (43.9%) and body functions (28.6%), according to the International Classification of Functioning, Disability, and Health. There is no standardized definition of minimal clinical datasets to measure and monitor health status of patients with spine-related MSK disorders in routine clinical practice. Common core elements identified were practicality, feasibility in a busy routine practice, time efficiency, and the capability to be used across different healthcare settings. CONCLUSION: Due to the absence of a standard definition for minimal clinical datasets for patients with spine-related MSK disorders, there is a lack of consistency in the selection of key data elements and patient-centered outcomes that should be included. More research on the implementation and feasibility of minimal clinical datasets in routine care settings is warranted and needed. It is essential to involve all relevant partners in the development process of minimal clinical datasets to ensure successful implementation and adoption in routine primary care.

Physiological responses to spinal manipulation therapy: investigation of the relationship between electromyographic responses and peak force.

OBJECTIVE: It is believed that systematic modulation of spinal manipulative therapy (SMT) parameters should yield varying levels of physiological responses and eventually a range of clinical responses. However, investigation of SMT dose-physiological response relationship is recent and has mostly been conducted using animal or cadaveric models. The main objective of the present study is to investigate SMT dose-physiological response relation in humans by determining how different levels of force can modify electromyographic (EMG) responses to spinal manipulation. METHODS: Twenty-six participants were subjected to 2 trials of 4 different SMT force-time profiles using a servo-controlled linear actuator motor. Normalized EMG activity of paraspinal muscles (left and right muscles at level T6 and T8) was recorded during and after SMT, and EMG values were compared across the varying levels of force. RESULTS: Increasing the level of force yielded an increase in paraspinal muscle EMG activity during the thrust phase of SMT but also in the two 250-millisecond time windows after the spinal manipulation impulse. These muscle activations quickly attenuated (500 milliseconds after spinal manipulation impulse). CONCLUSION: The study confirmed the presence of a local paraspinal EMG response after SMT and highlighted the linear relationship between the SMT peak force and paraspinal muscle activation.