Indication for spinal sensitization in chronic low back pain: mechanical hyperalgesia adjacent to but not within the most painful body area.

Introduction: In 85% of patients with chronic low back pain (CLBP), no specific pathoanatomical cause can be identified. Besides primary peripheral drivers within the lower back, spinal or supraspinal sensitization processes might contribute to the patients' pain. Objectives: The present study conceptualized the most painful area (MP) of patients with nonspecific CLBP as primarily affected area and assessed signs of peripheral, spinal, and supraspinal sensitization using quantitative sensory testing (QST) in MP, a pain-free area adjacent to MP (AD), and a remote, pain-free control area (CON). Methods: Fifty-nine patients with CLBP (51 years, SD = 16.6, 22 female patients) and 35 pain-free control participants individually matched for age, sex, and testing areas (49 years, SD = 17.5, 19 female participants) underwent a full QST protocol in MP and a reduced QST protocol assessing sensory gain in AD and CON. Quantitative sensory testing measures, except paradoxical heat sensations and dynamic mechanical allodynia (DMA), were Z-transformed to the matched control participants and tested for significance using Z-tests (α = 0.001). Paradoxical heat sensations and DMA occurrence were compared between cohorts using Fisher's exact tests (α = 0.05). The same analyses were performed with a high-pain and a low-pain CLBP subsample (50% quantile). Results: Patients showed cold and vibration hypoesthesia in MP (all Ps < 0.001) and mechanical hyperalgesia (P < 0.001) and more frequent DMA (P = 0.044) in AD. The results were mainly driven by the high-pain CLBP subsample. In CON, no sensory alterations were observed. Conclusion: Mechanical hyperalgesia and DMA adjacent to but not within MP, the supposedly primarily affected area, might reflect secondary hyperalgesia originating from spinal sensitization in patients with CLBP.

Lunar and mars gravity induce similar changes in spinal motor control as microgravity.

Introduction: Once more, plans are underway to send humans to the Moon or possibly even to Mars. It is therefore, important to know potential physiological effects of a prolonged stay in space and to minimize possible health risks to astronauts. It has been shown that spinal motor control strategies change during microgravity induced by parabolic flight. The way in which spinal motor control strategies change during partial microgravity, such as that encountered on the Moon and on Mars, is not known. Methods: Spinal motor control measurements were performed during Earth, lunar, Mars, and micro-gravity conditions and two hypergravity conditions of a parabola. Three proxy measures of spinal motor control were recorded: spinal stiffness of lumbar L3 vertebra using the impulse response, muscle activity of lumbar flexors and extensors using surface electromyography, and lumbar curvature using two curvature distance sensors placed at the upper and lower lumbar spine. The participants were six females and six males, with a mean age of 33 years (standard deviation: 7 years). Results: Gravity condition had a statistically significant (Friedmann tests) effect spinal stiffness (p < 0.001); on EMG measures (multifidus (p = 0.047), transversus abdominis (p < 0.001), and psoas (p < 0.001) muscles) and on upper lumbar curvature sensor (p < 0.001). No effect was found on the erector spinae muscle (p = 0.063) or lower curvature sensor (p = 0.170). Post hoc tests revealed a significant increase in stiffness under micro-, lunar-, and Martian gravity conditions (all p's < 0.034). Spinal stiffness decreased under both hypergravity conditions (all p's ≤ 0.012) and decreased during the second hypergravity compared to the first hypergravity condition (p = 0.012). Discussion: Micro-, lunar-, and Martian gravity conditions resulted in similar increases in spinal stiffness, a decrease in transversus abdominis muscle activity, with no change in psoas muscle activity and thus modulation of spinal motor stabilization strategy compared to those observed under Earth's gravity. These findings suggest that the spine is highly sensitive to gravity transitions but that Lunar and Martian gravity are below that required for normal modulation of spinal motor stabilization strategy and thus may be associated with LBP and/or IVD risk without the definition of countermeasures.

Responsiveness of the German version of the Neck Disability Index in chronic neck pain patients: a prospective cohort study with a seven-week follow-up.

BACKGROUND: The need for an efficient and feasible strategy to deal with neck pain has a high priority for many countries. Validated assessment tools like the Neck Disability Index (NDI) to evaluate the functional status of a neck pain patient are urgently needed to treat and to follow-up patients purposefully. A German version (NDI-G) was shown to be valid and reliable, but has so far not been tested for responsiveness. The aim of this study was to evaluate the NDI-G`s responsiveness. METHODS: This was a prospective cohort study with a seven-week follow-up. Fifty chronic neck pain patients filled out NDI-G twice. Additionally, the Patients' Global Impression of Change score (PGIC) was assessed at follow-up. Wilcoxon and Spearman tests were used to assess direction and strength of the association between the change in NDI-G and PGIC. The receiver operating characteristics method and the area under the curve (AUC) were calculated to assess sensitivity and specificity of the NDI-G change over time. RESULTS: The Wilcoxon test showed statistically significant differences for NDI-G at baseline and follow-up in the total sample, the "clinically improved" and "clinically not improved" subgroups as indicated in the PGIC. Spearman test resulted in a moderate correlation between the NDI-G and the PGIC (rS = -0.53, p = 0.01) at follow-up. AUC showed an acceptable discrimination [AUC = 0.78 (95% confidence interval 0.64 - 0.91)] of the NDI-G, with a cutoff score of 1.5, between clinically improved and clinically not improved patients, based on the PGIC. CONCLUSIONS: The NDI-G is responsive to change in chronic neck pain. Together with the results of a previous study on its validity and reliability, the NDI-G can be recommended for research and clinical settings in patients with neck pain in German speaking countries. TRIAL REGISTRATION: NCT02676141. February 8, 2016.

No alteration of back muscle oxygenation during isometric exercise in individuals with non-specific low back pain.

The aim of our study was (I) To compare back muscle oxygenation and perfusion as well as Biering-Sorensen muscle endurance (BSME) test holding times between chronic non-specific low back pain (CNSLBP) patients and asymptomatic controls matched for age, body mass index (BMI), sex and physical activity, and (II) to investigate factors associated with BSME holding times. Muscle perfusion (tHb) and oxygenation (SmO2) were measured by near-infrared spectroscopy (NIRS) based oximetry in three back muscles during the BSME. Reliability of tHb and SmO2 was assessed in a separate sample. BSME holding time and SmO2 were compared between patients (n = 45) and controls (n = 45) and factors associated with BSME holding time were assessed using multiple linear regression. Reliability for SmO2 was excellent (ICC = 0.87-0.99). THb showed poor to moderate reliability and was not further used. Groups differed for BSME holding time (P = 0.03), pain intensity (P ≤ 0.0005) and subcutaneous tissue thickness (P = 0.01) but not for NIRS measures. Physical activity and BMI were associated with BSME holding times. Insufficient muscle oxygenation does not seem to be a major factor contributing to CNSLBP. Future investigation should evaluate other determinants of BSME holding times, such as motivation and recruitment of auxiliary muscles.

Microgravity and Hypergravity Induced by Parabolic Flight Differently Affect Lumbar Spinal Stiffness.

The objective of this study was to determine the response of the lumbar spinal motor control in different gravitational conditions. This was accomplished by measuring indicators of lumbar motor control, specifically lumbar spinal stiffness, activity of lumbar extensor and flexor muscles and lumbar curvature, in hypergravity and microgravity during parabolic flights. Three female and five male subjects participated in this study. The mean age was 35.5 years (standard deviation: 8.5 years). Spinal stiffness of the L3 vertebra was measured using impulse response; activity of the erector spinae, multifidi, transversus abdominis, and psoas muscles was recorded using surface electromyography; and lumbar curvature was measured using distance sensors mounted on the back-plate of a full-body harness. An effect of gravity condition on spinal stiffness, activity of all muscles assessed and lumbar curvature (p's < 0.007) was observed (Friedman tests). Post hoc analysis showed a significant reduction in stiffness during hypergravity (p < 0.001) and an increase in stiffness during microgravity (p < 0.001). Activity in all muscles significantly increased during hypergravity (p's < 0.001). During microgravity, the multifidi (p < 0.002) and transversus abdominis (p < 0.001) increased significantly in muscle activity while no significant difference was found for the psoas (p = 0.850) and erector spinae muscles (p = 0.813). Lumbar curvature flattened in hypergravity as well as microgravity, albeit in different ways: during hypergravity, the distance to the skin decreased for the upper (p = 0.016) and the lower sensor (p = 0.036). During microgravity, the upper sensor showed a significant increase (p = 0.016), and the lower showed a decrease (p = 0.005) in distance. This study emphasizes the role of spinal motor control adaptations in changing gravity conditions. Both hypergravity and microgravity lead to changes in spinal motor control. The decrease in spinal stiffness during hypergravity is interpreted as a shift of the axial load from the spine to the pelvis and thoracic cage. In microgravity, activity of the multifidi and of the psoas muscles seems to ensure the integrity of the spine. Swiss (BASEC-NR: 2018-00051)/French "EST-III" (Nr-ID-RCB: 2018-A011294-51/Nr-CPP: 18.06.09).

Cervical Spine Disability in Correlation with Subjective Voice Handicap in Patients With Voice Disorders: A Retrospective Analysis.

OBJECTIVE: Neck muscle dysfunction has been considered as risk factor or consequence of voice disorders. This study investigates the correlation between neck and voice-related subjective symptoms in patients with voice disorders. STUDY DESIGN: Retrospective case-control study. METHODS: 100 adult patients (59 female and 41 male) over 18 years with a mean age of 50.01 years (SD 16, range 24-87), of which 68 were under 60 years, were included. 50 patients had organic voice pathologies and 50 functional dysphonia. Outcome measures were the Voice Handicap Index 9 international (VHI-9i) and the Neck Disability Index (NDI-G). Spearman rank order coefficient was applied to determine the correlation between overall and single item VHI and NDI results. Subanalyses were done for functional vs. organic disorder, gender and age ± 60 years. RESULTS: Mean overall VHI-9i (13.93, SD = 7.81, range = 0-31) and mean NDI-G (6.07, SD = 7.71, range = 0-43) showed a significant mild correlation (rs = 0.220, P = 0.02). Split into subgroups the relation was stronger in patients with organic pathologies (rs = 0.297, P = 0.03), but not significant in functional disorders (r = 0.148, P = 0.30). There was a moderate relation in men (rs = 0.317, P = 0.04). Single item correlation was highest between VHI-9i item P4 (physiological) and NDI-G item reading (cognitive functioning) (rs = 0.480, P = 0.002). CONCLUSION: Specifically patients with organic voice disorders showed increased voice symptoms with the presence of neck dysfunction. This indicates a risk for a functional imbalance of the muscles surrounding the larynx, which in extreme cases may hinder functional voice rehabilitation even after phonosurgery. Therefore, neck dysfunction should be considered in voice diagnostics.

Spinal Stiffness in Prone and Upright Postures During 0-1.8 g Induced by Parabolic Flight.

INTRODUCTION: The purpose of this study was to analyze posterior-to-anterior spinal stiffness in Earth, hyper-, and microgravity conditions during both prone and upright postures. CASE REPORT: During parabolic flight, the spinal stiffness of the L3 vertebra of a healthy 37-yr-old man was measured in normal Earth gravity (1.0 g), hypergravity (1.8 g), and microgravity (0.0 g) conditions induced in the prone and upright positions. Differences in spinal stiffness were significant across all three gravity conditions in the prone and upright positions. Most effect sizes were large; however, in the upright posture, the effect size between Earth gravity and microgravity was medium. Significant differences in spinal stiffness between the prone and upright positions were found during Earth gravity and hypergravity conditions. No difference was found between the two postures during microgravity conditions. DISCUSSION: Based on repeated measurements of a single individual, our results showed detectable changes in posterior-to-anterior spinal stiffness. Spinal stiffness increased during microgravity and decreased during hypergravity conditions. In microgravity conditions, posture did not impact spinal stiffness. More data on spinal stiffness in variable gravitational conditions is needed to confirm these results.Swanenburg J, Meier ML, Langenfeld A, Schweinhardt P, Humphreys BK. Spinal stiffness in prone and upright postures during 0-1.8 g induced by parabolic flight. Aerosp Med Hum Perform. 2018; 89(6):563-567.

Development and validation of a self-administered neck mobility assessment tool (S-ROM-Neck) in chronic neck pain patients.

BACKGROUND: Cervical spine (CS) range of motion (ROM) is commonly used to assess neck pain. However, this measurement is often limited by the clinician's experience and perception. Therefore, the integration of perceptual feedback of the patient can optimize and personalize treatment. OBJECTIVE: Develop and validate a questionnaire (S-ROM-Neck) to evaluate ROM of the CS from the patient's perspective. DESIGN: Validation study. METHODS: The assessment tool was developed and optimized during pretest sessions. Reliability and construct validity of the questionnaire were tested. 50 participants (age >18 years) with neck pain for >90 days, able to fluently speak, read, and write in German were included. Exclusion criteria included any condition that limited manual therapy to the CS. Participants completed S-ROM-Neck twice within seven days, along with the visual analogue scale (VAS) for pain intensity and the German version of the Neck Disability Index (NDI-G). The relative reliability, internal consistency, and absolute reliability were analyzed, and Bland-Altman plots were generated. Construct validity was established by correlating the total score of S-ROM-Neck with VAS and NDI-G based on pre-set hypotheses. RESULTS: S-ROM-Neck demonstrated moderate reliability with an intraclass correlation coefficient of 0.718 (Cronbach's alpha of 0.83). There was a medium negative correlation between VAS and S-ROM-Neck [Spearman's rank correlation coefficient (rs) = -0.30, p = 0.031] and the NDI-G and S-ROM-Neck (rs = -0.40, p = 0.002). CONCLUSIONS: These results indicate the reliability and internal consistency of S-ROM-Neck. This scale provides patient feedback and perspectives to optimize assessment of neck pain.

Validation of the Orebro musculoskeletal pain screening questionnaire in patients with chronic neck pain.

OBJECTIVES: To validate the German version of OMPSQ (OMPSQ-G) for patients with chronic neck pain. RESULTS: After translating OMPSQ to German, we assessed the discriminant validity between patients and healthy adults. Convergent validity was assessed using Pearson's correlation coefficients between domains of OMPSQ-G and the German version of neck disability index (NDI-G) and visual analogue scale (VAS) of neck pain intensity. Floor and ceiling effects, internal consistency, test-retest and relative reliability were assessed. Fifty patients with chronic neck pain (mean age, 43.6 years; 34 females) and 24 healthy adults (mean age, 50.4 years; 18 females) participated. Mann-Whitney U tests showed significant differences in OMPSQ scores between both groups at the baseline (z = - 4.6; p < 0.001) and second time point (z = - 4.8; p < 0.001). OMPSQ-G scores highly and moderately correlated with NDI-G (ρ = 0.70) and VAS (ρ = 0.41) scores, respectively. There were no floor or ceiling effects. Cronbach's alpha was 0.94. OMPSQ-G showed high reliability (intraclass correlation 2.1: 0.93; standard error of measurement, 6.9; smallest detectable change, 20 points). The Bland-Altman plot indicated no systematic error. OMPSQ-G showed good validity and reliability in patients with neck pain. Trial registration NCT02540343.

Patient's Subjective Impression of Cervical Range of Motion: A Mixed-methods Approach.

STUDY DESIGN: Mixed-method. OBJECTIVE: To evaluate the association between objective and subjective cervical range of motion (ROM) among patients with neck pain, and to assess the awareness of impairments. SUMMARY OF BACKGROUND DATA: Cervical ROM is frequently used to evaluate neck pain, but it is also important to know what a patient expects from treatment, because this can profoundly affect treatment outcomes and patient satisfaction. METHODS: We used a cervical ROM instrument, the Neck Disability Index (NDI), and a self-administered ROM questionnaire for the neck (S-ROM-Neck). Ten patients took part in semi-structured interviews. Correlations were analyzed using Spearman rank order correlations (rs). Differences between patient and assessor were evaluated by the Mann-Whitney U test. Qualitative data were analyzed by content analysis. RESULTS: Thirty participants (mean age 43.80 years; 21 females) were included. The correlation (rs) for the S-ROM-Neck between patient and assessor was 0.679 [95% confidence interval (95% CI) 0.404-0.884; P = 0.000]. The correlation between the NDI and S-ROM-Neck was 0.178 (95% CI -0.233 to -0.533; P = 346) for the assessor and -0.116 (95% CI -0.475 to -0.219, P = 0.541) for the patient (U = 448, z = -0.030, P = 0.976). Qualitative analysis revealed that patients had general restrictions in daily life and with specific movements, but that they adjusted their behavior to avoid impairment. CONCLUSION: There was a significant correlation between patient and therapist ratings of cervical spine mobility. Although patients experience restriction while moving and are impaired in specific activities, they adjust their lifestyle to accommodate their limitations. LEVEL OF EVIDENCE: 4.

Prognostic factors for recurrences in neck pain patients up to 1 year after chiropractic care.

OBJECTIVE: Information about recurrence and prognostic factors is important for patients and practitioners to set realistic expectations about the chances of full recovery and to reduce patient anxiety and uncertainty. Therefore, the purpose of this study was to assess recurrence and prognostic factors for neck pain in a chiropractic patient population at 1 year from the start of the current episode. METHODS: Within a prospective cohort study, 642 neck pain patients were recruited by chiropractors in Switzerland. After a course of chiropractic therapy, patients were followed up for 1 year regarding recurrence of neck pain. A logistic regression analysis was used to assess prognostic factors for recurrent neck pain. The independent variables age, pain medication usage, sex, work status, duration of complaint, previous episodes of neck pain and trauma onset, numerical rating scale, and Bournemouth questionnaire for neck pain were analyzed. Prognostic factors that have been identified in previous studies to influence recovery of neck pain are psychologic distress, poor general health at baseline, and a previous history of pain elsewhere. RESULTS: Five hundred forty five patients (341 females), with a mean age of 42.1 years (SD, 13.1) completed the 1-year follow-up period. Fifty-four participants (11%) were identified as "recurrent." Prognostic factors associated with recurrent neck pain were previous episodes of neck pain and increasing age. CONCLUSION: The results of this study suggest that recurrence of neck pain within 1 year after chiropractic intervention in Swiss chiropractic patients presenting from varied onsets is low. This study found preliminary findings that older age and a previous episode of neck may be useful predictors of neck pain recurrence within 1 year.

Effect of manual versus mechanically assisted manipulations of the thoracic spine in neck pain patients: study protocol of a randomized controlled trial.

BACKGROUND: Neck pain is a common musculoskeletal condition with a point prevalence of around 15% in males and 23% in females that often presents in physiotherapy practice. Physical therapy and/or manipulation therapy is generally the first management option for patients with mechanical neck pain. Physical therapists treat mechanical neck pain with a number of interventions including joint mobilization and/or manipulation, therapeutic exercises or education. However, manipulation of the cervical spine carries some risks. Treating the thoracic spine for neck pain is an alternative approach. Emerging evidence suggests that it may be effective for treating neck pain without the risks associated with cervical spine manipulation. A new electromechanical device has recently been developed and tested for delivering multiple high velocity, low amplitude thrust manipulations to the spine. This device incorporates both auditory and visual systems that provide real time feedback on the applied treatment. The objective of this study is to compare the short- and long-term effects of manual versus mechanically assisted manipulations of the thoracic spine for neck pain patients. METHODS/DESIGN: A 6-month, randomized controlled trial consisting of 54 patients with acute or chronic neck pain patients will be conducted. Patients with no signs of major pathology and with little or no interference with daily activities will be recruited. Three treatment sessions with 4-day intervals will be carried out. The patients will be randomly assigned to receive either manually performed manipulations or electromechanical manipulations at the thoracic spine. The primary outcome is pain intensity as measured by the Visual Analogue Pain Rating Scale. The secondary outcome measures are neck physical disability using the Neck Disability Index, quality of life measured by the European Quality of Life 5 Dimensions 5 Levels and patients' improvement using the Patient's Global Impression of Change Scale. DISCUSSION: It is expected that both interventions will improve neck pain. This would be a significant finding, as thoracic spine manipulation for neck pain does not carry the same risk of injury as cervical spine manipulation. In addition, the results may provide useful information about therapeutic options for health care providers and patients for the problem of neck pain. TRIAL REGISTRATION: Current Controlled Trials ISRCTN88585962, registered January 2013.

Validity and reliability of a German version of the Neck Disability Index (NDI-G).

The Neck Disability Index (NDI) is a widely used questionnaire in the assessment of disability of neck patients. The aim of this study was to translate the NDI according to established guidelines into German (NDI-G) and to test the psychometric properties. Patients with acute (ACU) and chronic neck pain (CHR) and a healthy control group (HCG) completed the NDI-G twice with a mean test-retest interval of 3 days. The total score of NDI-G showed high reliability (Intraclass correlation coefficient (ICC2,1) = 0.92) and a high Cronbach's alpha (α = 0.96). The minimal detectable change was 7 points. The Bland-Altman plot revealed a small positive systematic error of 1.02 points. The Kruskal-Wallis test showed significant differences in the NDI-G total score among the three groups (χ(2) = 29.77, p < 0.001). Mann-Whitney U tests showed significant differences in the total score between ACU and HCG (p < 0.001), and CHR and HCG (p < 0.001). The factor analysis of NDI-G yielded 2 factors that together explained 67% of the variance. Spearman's phi coefficients showed no correlation between the NDI-G total score and the visual analogue scale (VAS) in the ACU group (phi = 0.23, p = 0.40), and a moderate correlation in the CHR group (phi = 0.55, p = 0.03). The item analysis of the NDI-G revealed moderate to good reliability for all items. Only the item 'work' could differentiate between the ACU and CHR group. The NDI-G emerged from this study as a valid and reliable assessment. Its psychometric properties are comparable with the original version. Thus, the NDI-G is recommended for research and clinical settings in neck pain in German speaking countries.