Responsiveness of the cervical joint position error test to detect changes in neck proprioception following four weeks of home-based proprioceptive training.

INTRODUCTION: People with chronic neck pain (CNP) commonly exhibit a range of physical impairments including cervical proprioceptive deficits. Assessing proprioception using a head mounted laser to assess joint position error (JPE) is a reliable and valid measure. However, the responsiveness of this measure has not been assessed. OBJECTIVE: To assess the responsiveness of the measure of cervical JPE after a 4-week home-based neck proprioceptive training intervention in people with CNP. DESIGN: An observational study to assess the responsiveness of the measure of cervical JPE. METHODS: The JPE test was assessed in people with CNP before and after 4 weeks of neck proprioception training. JPE was assessed as participants performed neck joint position sense tests for flexion, extension, right rotation, and left rotation in sitting and standing which were performed in a random order. Both the absolute and constant JPE were assessed. The intervention consisted of neck repositioning exercises as well as movement sense exercises. Cohen's d effect size was used to assess the internal responsiveness of the JPE test. The Pearson's correlation was used to assess the change of scores of the laser pointer and measures from inertial measurement units (IMUs) (external responsiveness). RESULTS: After 4 weeks of proprioception training, JPE assessed in sitting reduced from 2.69◦-3.57◦ to 1.88◦-1.98◦ for flexion, extension, and right rotation with large effect sizes (Cohen's d range: 1.25-2.00). For left rotation, JPE reduced from 3.23◦ to 1.9◦, and the effect size was close to being large (Cohen's d: 0.79). When assessed in standing, JPE reduced from 3.49◦-4.52◦ to 1.5◦-2.33◦ with large effect sizes (Cohen's d range: 0.89-1.25) for flexion, extension, right rotation, and left rotation. Large effect sizes were not observed for the constant JPE when assessed in either sitting or standing. The assessment of the external responsiveness revealed weak correlations between the change of scores obtained from the laser pointer and the IMUs for all movements, apart from the constant JPE in sitting for left rotation, which showed a strong correlation (r = 0.7). CONCLUSION: The results of this study showed that the measure of the JPE has sufficient internal responsiveness, however, the external responsiveness was inadequate. Further research is advised.

The effects of neck exercise in comparison to passive or no intervention on quantitative sensory testing measurements in adults with chronic neck pain: A systematic review.

BACKGROUND: Previous systematic reviews have identified the benefits of exercise for chronic neck pain on subjective reports of pain, but not with objective measures such as quantitative sensory testing (QST). A systematic review was conducted to identify the effects of neck specific exercise on QST measures in adults with chronic neck pain to synthesise existing literature and provide clinical recommendations. METHODS: The study protocol was registered prospectively with PROSPERO (PROSPERO CRD42021297383). For both randomised and non-randomised trials, the following databases and trial registries were searched: AMED, CINAHL, Embase, Google Scholar, Medline, PEDro, PubMed, Scopus, SPORTDiscus, Science Citation Index and Social Science Citation Index from Web of Science Core Collection, clinicaltrials.gov, GreyOpen, and ISRCTN registry. These searches were conducted from inception to February 2022 and were updated until September 2023. Reference lists of eligible studies were screened. Study selection was performed independently by two reviewers, with data extraction and quality appraisal completed by one reviewer and independently ratified by a second reviewer. Due to high heterogeneity, narrative synthesis was performed with results grouped by exercise type. FINDINGS: Three trials were included. Risk of bias was rated as moderate and the certainty of evidence as low or moderate for all studies. All exercise groups demonstrated statistically significant improvement at an intermediate-term follow-up, with progressive resistance training combined with graded physical training demonstrating the highest certainty of evidence. Fixed resistance training demonstrated statistically significant improvement in QST measures at a short-term assessment. INTERPRETATION: Fixed resistance training is effective for short-term changes in pain sensitivity based on low-quality evidence, whilst moderate-quality evidence supports progressive resistance training combined with graded physical training for intermediate-term changes in pain sensitivity.

Biomechanical Posture Analysis in Healthy Adults with Machine Learning: Applicability and Reliability.

Posture analysis is important in musculoskeletal disorder prevention but relies on subjective assessment. This study investigates the applicability and reliability of a machine learning (ML) pose estimation model for the human posture assessment, while also exploring the underlying structure of the data through principal component and cluster analyses. A cohort of 200 healthy individuals with a mean age of 24.4 ± 4.2 years was photographed from the frontal, dorsal, and lateral views. We used Student's t-test and Cohen's effect size (d) to identify gender-specific postural differences and used the Intraclass Correlation Coefficient (ICC) to assess the reliability of this method. Our findings demonstrate distinct sex differences in shoulder adduction angle (men: 16.1° ± 1.9°, women: 14.1° ± 1.5°, d = 1.14) and hip adduction angle (men: 9.9° ± 2.2°, women: 6.7° ± 1.5°, d = 1.67), with no significant differences in horizontal inclinations. ICC analysis, with the highest value of 0.95, confirms the reliability of the approach. Principal component and clustering analyses revealed potential new patterns in postural analysis such as significant differences in shoulder-hip distance, highlighting the potential of unsupervised ML for objective posture analysis, offering a promising non-invasive method for rapid, reliable screening in physical therapy, ergonomics, and sports.

Consensus for experimental design in electromyography (CEDE) project: Checklist for reporting and critically appraising studies using EMG (CEDE-Check).

The diversity in electromyography (EMG) techniques and their reporting present significant challenges across multiple disciplines in research and clinical practice, where EMG is commonly used. To address these challenges and augment the reproducibility and interpretation of studies using EMG, the Consensus for Experimental Design in Electromyography (CEDE) project has developed a checklist (CEDE-Check) to assist researchers to thoroughly report their EMG methodologies. Development involved a multi-stage Delphi process with seventeen EMG experts from various disciplines. After two rounds, consensus was achieved. The final CEDE-Check consists of forty items that address four critical areas that demand precise reporting when EMG is employed: the task investigated, electrode placement, recording electrode characteristics, and acquisition and pre-processing of EMG signals. This checklist aims to guide researchers to accurately report and critically appraise EMG studies, thereby promoting a standardised critical evaluation, and greater scientific rigor in research that uses EMG signals. This approach not only aims to facilitate interpretation of study results and comparisons between studies, but it is also expected to contribute to advancing research quality and facilitate clinical and other practical applications of knowledge generated through the use of EMG.

Higher Neck Pain Intensity and Pain Catastrophizing Soon After A Whiplash Injury Partially Explain the Presence of Persistent Headache: A Prospective Study.

OBJECTIVE: To understand whether pain-related factors soon after a whiplash injury can explain the presence of chronic headache. MATERIALS AND METHODS: A prospective study with a follow-up of 6 months was performed, including 42 patients with acute whiplash-associated disorders. Neck pain intensity, the Neck Disability Index, the Tampa Scale of Kinesiophobia, the Pain Catastrophizing Scale, and the Anxiety State-Trait Scale were assessed at baseline. Differences in clinical characteristics between those with and without headache at 6 months were determined. The relative risk of presenting with headache was evaluated. A logistic regression model was performed to assess which factors at baseline could explain the presence of headache at 6 months. RESULTS: At 6 months, one-third of the sample presented with chronic headache. Significant differences were found for several outcome measures when people with and without headache were compared ( P <0.001). The highest relative risk of presenting with headache was found for moderate/severe levels of pain catastrophizing during the acute phase (RR=15.00, 95% CI=3.93, 57.22). The level of neck pain intensity and pain catastrophizing at baseline partially explained the presence of headache at 6 months ( R2 =0.627). DISCUSSION: The risk of presenting with persistent headache attributed to a whiplash injury is increased when people present with higher neck pain intensity and pain catastrophizing soon after a whiplash injury. Evaluating neck pain intensity and pain catastrophizing at baseline may assist in identifying those more likely to develop chronic headache, potentially providing an opportunity for early targeted interventions.

Changes in Multiple Aspects of Pain Outcomes After Rehabilitation: Analysis of Pain Data in a Randomized Controlled Trial Evaluating the Effects of Adding Sensorimotor Training to Manual Therapy and Exercise for Chronic Neck Pain.

OBJECTIVES: To examine changes in pain outcomes to fully evaluate the effect of adding sensorimotor training to manual therapy and exercise in patients with chronic neck pain and sensorimotor deficits. Concordance was examined between pain distribution and pain intensity and patient-reported outcomes. METHODS: Participants (n=152) were randomly allocated into 4 intervention groups: One group received local neck treatment (NT) comprising manual therapy and exercise and the other 3 groups received additional sensorimotor training (either joint position sense/oculomotor exercises, balance exercises or both). Treatment was delivered twice a week for 6 weeks. Pain and patient-reported outcomes were measured at baseline, posttreatment, and 3-, 6- and 12-month follow-ups. RESULTS: There were greater changes in pain location, extent, and intensity at 6- and 12-month follow-ups in the sensorimotor training groups compared with the NT group ( P <0.05). A greater number of patients in the sensorimotor training groups gained ≥50% reduction in pain extent and intensity relative to the NT group at 6 and 12 months ( P <0.05). Clinical improvement in pain extent was concordant with pain intensity (adjusted kappa=056 to 0.66, %agreement=78.3 to 82.9, P <0.001) and disability (adjusted kappa=0.47 to 0.58, % agreement=73.7 to 79.0, P <0.01) at 3-, 6- and 12-month follow-ups, but not with function and well-being. The concordance tended to decline with time. DISCUSSION: Multiple aspects of the pain experience improved in the longer term by adding sensorimotor training to NT for patients with neck pain and sensorimotor deficits. The concordance between pain and patient-reported outcomes was not always evident and varied over time, suggesting the need for multidimensional assessments of pain.

The influence of exercise on pain, disability and quality of life in office workers with chronic neck pain: A systematic review and meta-analysis.

BACKGROUND: Exercise is recommended for office workers with neck pain. However, recent reviews evaluated the effectiveness of workplace interventions only. OBJECTIVES: To evaluate the effect of exercise on pain, disability, and quality of life (QoL) in office workers with chronic neck pain. DESIGN: Systematic review with meta-analysis. METHODS: Electronic databases were searched from inception to April 30, 2022, to identify studies in which participants were adults aged ≥18 years undergoing any form of neck exercises (e.g., strengthening, motor control) or physical activity (e.g., aerobic exercise) performed for a minimum of two-weeks without any other additional treatment besides advice or education. Two reviewers independently screened papers and determined the certainty of the evidence. RESULTS: Eight randomised controlled trials met the eligibility criteria. Seven studies reported a significant decrease in Visual Analogue Scale (VAS) scores for neck pain intensity and five studies reported a significant decrease in Neck Disability Index (NDI) scores following strengthening exercises. Only one study assessed the effect of strengthening exercises on QoL and reported no significant effect. All eight included studies had a high risk of bias and the overall certainty of evidence was low. Meta-analyses demonstrated a significant decrease of neck pain intensity and disability for strengthening exercises compared to a control (p < 0.01). CONCLUSION: There is low certainty of evidence that strengthening of the neck, shoulder and scapular musculature is effective at reducing neck pain and disability in office workers. Further research evaluating the effect of exercise on QoL is required.

A Profile of Isometric Cervical Strength in Elite Professional Male Rugby Players.

OBJECTIVES: To (1) provide position-specific normative data for isometric cervical muscle strength and endurance in professional, male rugby players and (2) assess the relationship between age, height, weight, and playing position with cervical muscle strength and endurance. DESIGN: Cross-sectional study. METHODS: Professional rugby players completed peak isometric cervical strength testing followed by a test of cervical muscle endurance. Descriptive statistics for continuous variables with strength normalized to body weight were performed. Multiple linear regression was used to estimate associations between strength measurements. RESULTS: In total, 136 players participated including front-row forwards (27%), other forwards (28%), and backs (45%). Front-row forwards had significantly greater peak isometric cervical muscle strength than other position groups, with backs having the lowest strength. Extension produced the highest force for all 3 position groups (429 N ± 104 N), whereas flexion produced the least (275 N ± 65 N). Age was associated with increased isometric cervical muscle strength. There was a statistically significant relationship between peak flexion strength and flexion endurance (P = .003). The average time for the endurance tests were 55.7 (±17.1) seconds and 52.9 (±20.1) seconds for extension and flexion, respectively. Other forwards had lower cervical extension muscle endurance than backs and front-row forwards. CONCLUSIONS: Normative values for peak and endurance isometric strength in professional rugby players illustrate significant differences between playing position. Consider age, body weight, and intraindividual variability when interpreting cervical strength and endurance results. J Orthop Sports Phys Ther 2024;54(3):1-8. Epub 29 January 2024. doi:10.2519/jospt.2024.11830.

Measurement properties of cervical joint position error in people with and without neck pain: a systematic review and narrative synthesis.

INTRODUCTION: Proprioception can be impaired in people with neck pain. The cervical joint position sense test, which measures joint position error (JPE), is the most common test used to assess neck proprioception. The aim of this systematic review was to assess the measurement properties of this test for the assessment of people with and without neck pain. METHODS: This systematic review was registered prospectively on Prospero (CRD42020188715). It was designed using the COSMIN guidelines and reported in line with the PRISMA checklist. Two reviewers independently searched Medline, Embase, SportDiscus, and CINAHL Plus databases from inception to the 24th July 2022 with an update of the search conducted until 14th of October 2023. The COSMIN risk of bias checklist was used to assess the risk of bias in each study. The updated criteria for good measurement properties were used to rate individual studies and then the overall pooled results. The level of evidence was rated by two reviewers independently using a modified GRADE approach. RESULTS: Fifteen studies were included in this review, 13 reporting absolute JPE and 2 reporting constant JPE. The measurement properties assessed were reliability, measurement error, and validity. The measurement of JPE showed sufficient reliability and validity, however, the level of evidence was low/very low for both measurement properties, apart from convergent validity of the constant JPE, which was high. CONCLUSION: The measure of cervical JPE showed sufficient reliability and validity but with low/very low levels of evidence. Further studies are required to investigate the reliability and validity of this test as well as the responsiveness of the measure.

Low Back Pain-Induced Dynamic Trunk Muscle Control Impairments Are Associated with Altered Spatial EMG-Torque Relationships.

PURPOSE: We quantified the relationship between high-density surface electromyographic (HDsEMG) oscillations (in both time and frequency domains) and torque steadiness during submaximal concentric/eccentric trunk extension/flexion contractions, in individuals with and without chronic low back pain (CLBP). METHODS: Comparisons were made between regional differences in HDsEMG amplitude and HDsEMG-torque cross-correlation and coherence of the thoracolumbar erector spinae (ES), rectus abdominis (RA), and external oblique (EO) muscles between the two groups. HDsEMG signals were recorded from the thoracolumbar ES with two 64-electrode grids and from the RA and EO muscles with a single 64-electrode grid placed over each muscle. Torque signals were recorded with an isokinetic dynamometer. Coherence (δ band (0-5 Hz)) and cross-correlation analyses were used to examine the relationship between HDsEMG and torque signals. For this purpose, we used principal component analysis to reduce data dimensionality and improve HDsEMG-based torque estimation. RESULTS: We found that people with CLBP had poorer control during both concentric and eccentric trunk flexion and extension. Specifically, during trunk extension, they exhibited a higher HDsEMG-torque coherence in more cranial regions of the thoracolumbar ES and a higher HDsEMG cross-correlation compared with asymptomatic controls. During trunk flexion movements, they demonstrated higher HDsEMG amplitude of the abdominal muscles, with the center of activation being more cranial and a higher contribution of this musculature to the resultant torque (particularly the EO muscle). CONCLUSIONS: Our findings underscore the importance of evaluating torque steadiness in individuals with CLBP. Future research should consider the value of torque steadiness training and HDsEMG-based biofeedback for modifying trunk muscle recruitment strategies and improving torque steadiness performance in individuals with CLBP.

Outcome measures for young people with adolescent idiopathic scoliosis: A qualitative exploration of healthcare professionals' perceptions and practices.

BACKGROUND: Limited knowledge exists on current use of patient reported outcome measures (PROMs) and performance measures for adolescents with idiopathic scoliosis (AIS), as well as health care professionals' (HCPs) perceived barriers and facilitators towards their use. This study's objectives were: 1) to explore current practice of HCPs when assessing outcomes for AIS 2) to understand perceived barriers and facilitators of HCPs to use PROMs 3) to understand perceived barriers and facilitators of HCPs to use performance measures. METHODS: A qualitative study recruited a purposive sample of HCPs from a tertiary hospital in the United Kingdom. Mean years of experience managing individuals with AIS was 11.8 years; and included surgeons, physiotherapists and nurses, educated at Bachelor, Masters and Doctoral level. Consent to participate and demographic information were collected in advance of the interviews. In-depth, virtual semi-structured interviews were informed by a topic guide based on current evidence. Interviews of approximately 45 minutes were audio and video recorded and transcribed verbatim alongside written field notes. Data were coded and analysed using inductive thematic analysis, involving researchers with topic and methodological expertise and input from a patient representative. RESULTS: Two themes emerged regarding current practice of using PROMs routine practice and personal evaluations. Four themes emerged as barriers to using PROMs for individuals with AIS: priority and support (e.g., HCPs focus on providing care), practical challenges (e.g., inadequate PROMs), patient-related challenges (e.g., patient preferences) and knowledge, education, and perceived value. Two themes emerged as facilitators: quality existing measure (e.g., sufficient psychometric properties), and priority and support (e.g., research department/culture). Themes for barriers to use performance measures were practicality (e.g., need physical space) and perceived value and knowledge (e.g., PROMs are more important), while the one theme for facilitators was practical consideration (e.g., acceptability). CONCLUSIONS: Although HCPs perceived the value of using outcome measures, current practice indicates limited use for individuals with AIS. The findings revealed different barriers and facilitators to implement PROMs in practice. Adopting performance measure are limited due to lack of knowledge and perceived value alongside the practicality, while considering practical factors can improve the use of these measures in practice.

Reliability, Measurement Error, Responsiveness, and Minimal Important Change of the Patient-Specific Functional Scale 2.0 for Patients With Nonspecific Neck Pain.

OBJECTIVE: The Patient-Specific Functional Scale (PSFS) is a patient-reported outcome measure used to assess functional limitations. Recently, the PSFS 2.0 was proposed; this instrument includes an inverse numeric rating scale and an additional list of activities that patients can choose. The aim of this study was to assess the test-retest reliability, measurement error, responsiveness, and minimal important change of the PSFS 2.0 when used by patients with nonspecific neck pain. METHODS: Patients with nonspecific neck pain completed a numeric rating scale, the PSFS 2.0, and the Neck Disability Index at baseline and again after 12 weeks. The Global Perceived Effect (GPE) was also collected at 12 weeks and used as an anchor. Test-retest measurement was assessed by completion of a second PSFS 2.0 after 1 week. Measurement error was calculated using a Bland-Altman plot. The receiver operating characteristic method with the anchor (GPE) functions as the reference standard was used for calculating the minimal important change. RESULTS: One hundred patients were included, with 5 lost at follow-up. No floor and ceiling effects were reported. In the test-retest analysis, the mean difference was 0.15 (4.70 at first test and 4.50 at second test). The ICC (mixed models) was 0.95, indicating high agreement (95% CI = 0.92-0.97). For measurement error, the upper and lower limits of agreement were 0.95 and -1.25 points, respectively, with a smallest detectable change of 1.10. The minimal important change was determined to be 2.67 points. The PSFS 2.0 showed satisfactory responsiveness, with an area under the curve of 0.82 (95% CI = 0.70-0.93). There were substantial to high correlations between the change scores of the PSFS 2.0 and the Neck Disability Index and GPE (0.60 and 0.52, respectively; P < .001). CONCLUSION: The PSFS 2.0 is a reliable and responsive patient-reported outcome measure for use by patients with neck pain.

Effect of movement-evoked and tonic experimental pain on muscle force production.

INTRODUCTION: When performing an exercise or a functional test, pain that is evoked by movement or muscle contraction could be a stronger stimulus for changing how individuals move compared to tonic pain. We investigated whether the decrease in muscle force production is larger when experimentally-induced knee pain is directly associated to the torque produced (movement-evoked) compared to a constant painful stimulation (tonic). METHODS: Twenty-one participants performed three isometric knee extension maximal voluntary contractions without pain (baseline), during pain, and after pain. Knee pain was induced using sinusoidal electrical stimuli at 10 Hz over the infrapatellar fat pad, applied continuously or modulated proportionally to the knee extension torque. Peak torque and contraction duration were averaged across repetitions and normalized to baseline. RESULTS: During tonic pain, participants reported lower pain intensity during the contraction than at rest (p < 0.001), whereas pain intensity increased with contraction during movement-evoked pain (p < 0.001). Knee extension torque decreased during both pain conditions (p < 0.001), but a larger reduction was observed during movement-evoked compared to tonic pain (p < 0.001). Participants produced torque for longer during tonic compared to movement-evoked pain (p = 0.005). CONCLUSION: Our results indicate that movement-evoked pain was a more potent stimulus to reduce knee extension torque than tonic pain. The longer contraction time observed during tonic pain may be a result of a lower perceived pain intensity during muscle contraction. Overall, our results suggest different motor adaptation to tonic and movement-evoked pain and support the notion that motor adaptation to pain is a purposeful strategy to limit pain. This mechanistic evidence suggests that individuals experiencing prevalently tonic or movement-evoked pain may exhibit different motor adaptations, which may be important for exercise prescription.

Network analyses reveal the interaction between physical features, fear of movement and neck pain and disability in people with acute and chronic whiplash-associated disorders.

BACKGROUND AND OBJECTIVE: A network analysis can be used to quantitatively assess and graphically describe multiple interactions. This study applied network analyses to determine the interaction between physical and pain-related factors and fear of movement in people with whiplash-associated disorders (WAD) during periods of acute and chronic pain. METHODS: Physical measurements, including pressure pain-thresholds (PPT) over neural structures, cervical range of motion, neck flexor and extensor endurance and the cranio-cervical flexion test (CCFT), in addition to subjective reports including the Tampa Scale of Kinesiophobia (TSK-11), Neck Disability Index (NDI) and neck pain and headache intensity, were assessed at baseline in 47 participants with acute WAD. TSK-11, NDI and pain intensity were assessed for the same participants 6 months later (n = 45). Two network analyses were conducted to estimate the associations between features at baseline and at 6 months and their centrality indices. RESULTS: Both network analyses revealed that the greatest weight indices were found for NDI and CCFT at baseline and for neck pain and headache intensity and NDI and TSK-11 at both time points. Associations were also found betweeen cervical muscle endurance and neck pain intensity in the acute phase. Cervical muscle endurance assesssed during the acute phase was also associated with NDI after 6 months - whereas PPT measured at baseline was associsated with headache intensity after 6 months. CONCLUSION: The strongest associations were found for headache and neck pain intensity and neck disability and fear of movement, both during acute pain and when mesured 6 months later. The extent of neck endurance and measures of PPT at baseline may be associated with neck disability and headache, respectively, 6 months after a whiplash injury. SIGNIFICANCE: Through two network analyses, we evaluated the interaction between pain-related factors, fear of movement, neck disability and physical factors in people who had experienced a whiplash injury. We demonstrated that physical factors may be involved in the maintenance and development of chronic pain after a whiplash injury. Nevertheless, the strongest associations were found for headache and neck pain intensity and neck disability and fear of movement, both during acute and chronic phases.

Prognostic Factors of Perceived Disability and Perceived Recovery After Whiplash: A Longitudinal, Prospective Study With One-year Follow-up.

OBJECTIVES: The understanding of the role that cognitive and emotional factors play in how an individual recovers from a whiplash injury is important. Hence, we sought to evaluate whether pain-related cognitions (self-efficacy beliefs, expectation of recovery, pain catastrophizing, optimism, and pessimism) and emotions (kinesiophobia) are longitudinally associated with the transition to chronic whiplash-associated disorders in terms of perceived disability and perceived recovery at 6 and 12 months. METHODS: One hundred sixty-one participants with acute or subacute whiplash-associated disorder were included. The predictors were: self-efficacy beliefs, expectation of recovery, pain catastrophizing, optimism, pessimism, pain intensity, and kinesiophobia. The 2 outcomes were the dichotomized scores of perceived disability and recovery expectations at 6 and 12 months. Stepwise regression with bootstrap resampling was performed to identify the predictors most strongly associated with the outcomes and the stability of such selection. RESULTS: Baseline perceived disability, pain catastrophizing, and expectation of recovery were the most likely to be statistically significant, with an overage frequency of 87.2%, 84.0%, and 84.0%, respectively. CONCLUSION: Individuals with higher expectations of recovery and lower levels of pain catastrophizing and perceived disability at baseline have higher perceived recovery and perceived disability at 6 and 12 months. These results have important clinical implications as both factors are modifiable through health education approaches.

Reliability of the Pen-on-Paper Pain Drawing Analysis Using Different Scanning Procedures.

INTRODUCTION: Pen-on-paper pain drawing are an easily administered self-reported measure that enables patients to report the spatial distribution of their pain. The digitalization of pain drawings has facilitated the extraction of quantitative metrics, such as pain extent and location. This study aimed to assess the reliability of pen-on-paper pain drawing analysis conducted by an automated pain-spot recognition algorithm using various scanning procedures. METHODS: One hundred pain drawings, completed by patients experiencing somatic pain, were repeatedly scanned using diverse technologies and devices. Seven datasets were created, enabling reliability assessments including inter-device, inter-scanner, inter-mobile, inter-software, intra- and inter-operator. Subsequently, the automated pain-spot recognition algorithm estimated pain extent and location values for each digitized pain drawing. The relative reliability of pain extent analysis was determined using the intraclass correlation coefficient, while absolute reliability was evaluated through the standard error of measurement and minimum detectable change. The reliability of pain location analysis was computed using the Jaccard similarity index. RESULTS: The reliability analysis of pain extent consistently yielded intraclass correlation coefficient values above 0.90 for all scanning procedures, with standard error of measurement ranging from 0.03% to 0.13% and minimum detectable change from 0.08% to 0.38%. The mean Jaccard index scores across all dataset comparisons exceeded 0.90. CONCLUSIONS: The analysis of pen-on-paper pain drawings demonstrated excellent reliability, suggesting that the automated pain-spot recognition algorithm is unaffected by scanning procedures. These findings support the algorithm's applicability in both research and clinical practice.

Home-based arm cycling exercise improves trunk control in persons with incomplete spinal cord injury: an observational study.

Arm cycling is used for cardiorespiratory rehabilitation but its therapeutic effects on the neural control of the trunk after spinal cord injury (SCI) remain unclear. We investigated the effects of single session of arm cycling on corticospinal excitability, and the feasibility of home-based arm cycling exercise training on volitional control of the erector spinae (ES) in individuals with incomplete SCI. Using transcranial magnetic stimulation, we assessed motor evoked potentials (MEPs) in the ES before and after 30 min of arm cycling in 15 individuals with SCI and 15 able-bodied controls (Experiment 1). Both groups showed increased ES MEP size after the arm cycling. The participants with SCI subsequently underwent a 6-week home-based arm cycling exercise training (Experiment 2). MEP amplitudes and activity of the ES, and movements of the trunk during reaching, self-initiated rapid shoulder flexion, and predicted external perturbation tasks were measured. After the training, individuals with SCI reached further and improved trajectory of the trunk during the rapid shoulder flexion task, accompanied by increased ES activity and MEP amplitudes. Exercise adherence was excellent. We demonstrate preserved corticospinal drive after a single arm cycling session and the effects of home-based arm cycling exercise training on trunk function in individuals with SCI.

High-density surface electromyography allows to identify risk conditions and people with and without low back pain during fatiguing frequency-dependent lifting activities.

Low back pain (LBP) is a leading cause of disability in the workplace, often caused by manually lifting of heavy loads. Instrumental-based assessment tools are used to quantitatively assess the biomechanical risk of lifting activities. This study aims to verify that, during the execution of fatiguing frequency-dependent lifting, high-density surface electromyography (HDsEMG) allows the discrimination of healthy controls (HC) versus people with LBP and biomechanical risk levels. Fifteen HC and eight people with LBP performed three lifting tasks with a progressively increasing lifting index, each lasting 15 min. Erector spinae (ES) activity was recorded using HDsEMG and amplitude parameters were calculated to characterize the spatial distribution of muscle activity. LBP group showed a less ES activity than HC (lower root mean square across the grid and of the activation region) and an involvement of the same muscular area across the task (lower coefficient of variation of the center of gravity of muscle activity). The results indicate the usefulness of HDsEMG parameters to classify risk levels for both HC and LBP groups and to determine differences between them. The findings suggest that the use of HDsEMG could expand the capabilities of existing instrumental-based tools for biomechanical risk classification during lifting activities.

Shear Wave Tensiometry Can Detect Loading Differences Between Operated and Unaffected Achilles Tendon.

BACKGROUND: The clinically relevant healing process of a ruptured and repaired Achilles tendon (AT) can last more than a year. The purpose of this cross-sectional study was to test if shear wave tensiometry is able to detect AT loading changes between a surgically managed AT rupture versus the unaffected contralateral tendon. Our secondary aims were to evaluate differences in mechanical properties when measured with myotonometry and morphological properties of the tendons measured with ultrasonographic imaging. METHODS: Twenty-one patients with surgically treated AT ruptures were investigated 12-37 months after surgery. Tendon load was measured using a shear wave tensiometer composed of an array of 4 accelerometers fixed on the tendon. Shear wave speed along the Achilles tendon was evaluated at different levels of ankle torque for both the operated and the unaffected side. Mechanical properties of the tendons were evaluated using MyotonPRO and morphological properties using ultrasonographic imaging. Friedman test was used to assess differences in AT wave speed, stiffness, thickness, and cross-sectional area between the operated and the unaffected tendon. RESULTS: We found a significant shear wave speed difference between sides at every ankle joint torque (P < .05) with a large effect size for the lowest ankle torque and small to medium effect sizes for higher ankle torque. Stiffness, thickness, and cross-sectional area of the operated tendon remained significantly higher compared to the unaffected side. CONCLUSION: In this cohort, we found that shear wave tensiometry can detect differences between operated and unaffected AT during a standardized loading procedure. The shear wave speed along the operated tendon, as well as the mechanical and morphologic properties, remains higher for 1-3 years after a rupture. LEVEL OF EVIDENCE: Level III, case-control study.

Spinal kinematic variability is increased in people with chronic low back pain during a repetitive lifting task.

Changes in spinal kinematic variability have been observed in people with chronic non-specific LBP (CNSLBP) during the performance of various repetitive functional tasks. However, the direction of these changes (i.e., less or more kinematic variability) is not consistent. This study aimed to assess differences in kinematic variability of the 3D angular displacement of thoracic and lumbar spinal segments in people with CNSLBP compared to asymptomatic individuals during a repetitive lifting task. Eleven people with CNSLBP and 11 asymptomatic volunteers performed 10 cycles of multi-planar lifting movements while spinal kinematics were recorded. For the three planes of motion, point-by-point standard deviations (SDs) were computed across all cycles of lifting and the average was calculated as a measure of kinematic variability for both segments. People with CNSLBP displayed higher thoracic (F = 8.00, p = 0.010, ηp2 = 0.286) and lumbar kinematic variability (F = 5.48, p = 0.030, ηp2 = 0.215) in the sagittal plane. Moreover, group differences were observed in the transversal plane for thoracic (F = 7.62, p = 0.012, ηp2 = 0.276) and lumbar kinematic variability (F = 5.402, p = 0.031, ηp2 = 0.213), as well as in the frontal plane for thoracic (F = 7.27, p = 0.014, ηp2 = 0.267) and lumbar kinematic variability (F = 6.11, p = 0.022, ηp2 = 0.234), all showing higher variability in those with CNSLBP. A significant main effect of group was not detected (p > 0.05) for spinal range of motion (ROM). Thus, people with CNSLBP completed the lifting task with the same ROM in all three planes of motion as observed for asymptomatic individuals, yet they performed the lifting task with higher spinal kinematic cycle-to-cycle variation.