Previous studies have shown that postural orientations of the neck, such as flexed or forward head postures, are associated with heightened activity of the dorsal neck muscles. While these studies describe the impact of variations in neck posture alone, there is scant literature regarding the effect of neck posture on muscle activity when combined with upper limb activities such as lifting. The purpose of this study was to evaluate the effect of three different neck postures on the activity of the different layers of the dorsal neck muscles during a lifting task. Ultrasound measurements of dorsal neck muscle deformation were compared over two time points (rest, during lift) during a lifting task performed in three different neck postural conditions (neutral, flexed and forward head posture) in 21 healthy subjects. Data were analysed by post-process speckle tracking analysis. Results demonstrated significantly greater muscle deformation induced by flexed and forward head postures, compared to the neutral posture, for all dorsal neck muscles at rest (pless than. 0.05). Significant condition by time interactions associated with the lift was observed for four out of the five dorsal muscles (pless than. 0.02). These findings demonstrate that posture of the cervical spine influenced the level of muscle deformation not only at rest, but also when lifting. The findings of the study suggest that neck posture should be considered during the evaluation or design of lifting activities as it may contribute to excessive demands on dorsal neck muscles with potential detrimental consequences.

This study investigates the interactions between self-efficacy–including subcomponents–and symptoms (pain, depression, and anxiety), catastrophizing, disability, quality of life, and health in a population of chronic pain patients. The study used 433 chronic pain patients including 47 patients with spinal cord injuryrelated pain, 150 with chronic whiplash-associated disorders, and 236 with fibromyalgia. The participants answered a postal questionnaire that provided background data, pain intensity and duration, and psychological- and health-related items. In the multivariate context, depression, anxiety, catastrophizing, and disability were intercorrelated. Self-efficacy correlated positively with variables of quality of life and general health. These two groups of variables were negatively correlated. The pain variables–duration of pain, pain intensity, and spreading of pain–formed a third group of variables. Self-efficacy function was negatively correlated to these three pain variables. When regressing disability, quality of life, and health, we found that self-efficacy had a positive impact whereas symptoms, catastrophizing, and pain had a negative influence on these aspects. Different patterns of influencing variables were discerned for the three different analyses, and specific patterns of the subscales of self-efficacy corresponded to specific patterns of negative factors for the outcome of disability, quality of life, and health.

Perspective: This article presents the complex interaction of psychological factors and symptoms and their positive and negative influence on disability, quality of life, and health. The results indicate that it might be important to assess and influence both enhancing and detoriating factors to ensure an effective pain management programme.

Purpose: To identify subgroups of chronic pain patients based on the occurrence of depression, anxiety, and catastrophizing and the duration of pain and pain intensity. In addition to this, to investigate the relationship between the subgroups with respect to background variables, diagnosis, pain-related disability, and perceived quality of life.

Methods: This study used 433 chronic pain patients including 47 patients with spinal cord injury related pain, 150 with chronic whiplash associated disorders, and 236 with fibromyalgia. The participants answered a postal questionnaire that provided background data, pain intensity and duration and psychological and health related items.

Results: Based on depression, anxiety, catastrophizing, pain intensity and duration, we identified subgroups of chronic pain patients that differed with respect to perceived quality of life, disability and diagnosis. The psychological factors, especially depression, significantly influenced perceived quality of life and disability. Pain intensity and duration play a minor role with respect to quality of life although pain intensity is associated contributes more to perceived disability.

Conclusions: The results of this study highlight the importance of not looking at chronic pain patients as a homogenous entity. A detailed assessment, including psychological factors with emphasis on depressive symptoms, might be essential for planning and carrying through treatment and rehabilitation.

Background. Different research techniques indicate alterations in muscle tissue and in neuromuscular control of aching muscles in patients with chronic localized pain. Ultrasound can be used for analysis of muscle tissue dynamics in clinical practice. Aim. This study introduces a new muscle tissue sensitive ultrasound technique in order to provide a new methodology for providing a description of local muscle changes. This method is applied to investigate trapezius muscle tissue response - especially with respect to specific regional deformation and deformation rates - during concentric shoulder elevation in patients with chronic trapezius myalgia and healthy controls before and after pain provocation. Methods. Patients with trapezius myalgia and healthy controls were analyzed using an ultrasound system equipped with tissue velocity imaging (TVI). The patients performed a standardized 3-cm concentric shoulder elevation before and after pain provocation/exercise at a standardized elevation tempo (30 bpm). A standardized region of interest (ROI), an ellipsis with a size that captures the upper and lower fascia of the trapezius muscle (4 cm width) at rest, was placed in the first frame of the loop registration of the elevation. The ROI was re-anchored frame by frame following the same anatomical landmark in the basal fascia during all frames of the concentric phase. In cardiac measurement, tissue velocities are measured in the axial projection towards and against the probe where red colour represents shortening and red lengthening. In the case of measuring the trapezius muscle, tissue deformation measurements are made orthogonally, thus, indirectly. Based on the assumption of muscle volume incompressibility, blue represents tissue contraction and red relaxation. Within the ROI, two variables were calculated as a function of time: deformation and deformation rate. Hereafter, max, mean, and quadratic mean values (RMS) of each variable were calculated and compared before and after pain provocation/ exercise. Results. This new methodology seems valuable when looking at local muscle changes and studying the mechanism behind chronic muscle pain. The univariate analyses indicate that patients with chronic trapezius myalgia after pain provocation due to exercise at group level showed decreased strain and unchanged strain rate while healthy controls had unchanged strain and increased strain rate. However, the multivariate analysis indicates that most patients showed lower levels according to both strain and strain rate after exercise compared to most controls. Conclusion. Tissue velocity imaging can help describe musculoskeletal tissue activity and dynamics in patients with chronic pain conditions. An altered muscle tissue dynamic after pain provocation/exercise among the majority of trapezius myalgia patients compared with the healthy controls was found. © 2008 Peolsson et al, licensee BioMed Central Ltd.

The mechanisms behind the development of chronic trapezius myalgia in patients with whiplash associated disorders (WAD) appear to involve both peripheral and central components, but the specific contribution of alterations in muscle is not clear. Female patients with WAD and involvement of trapezius (N = 22) and female controls (N = 20; CON) were studied during an experiment compromised of rest (baseline), 20 min repetitive low-force exercise and 120 min recovery. Their interstitial concentrations of serotonin (5-HT), glutamate, lactate, pyruvate, potassium, interleukin-6 (IL-6), and blood flow were determined in the trapezius muscle using a microdialysis technique. Pressure pain thresholds (PPT) over trapezius and tibialis anterior muscles were also assessed. In WAD, we found signs of generalized hypersensitivity according to PPT. The WAD group had significantly higher interstitial [IL-6] and [5-HT] in the trapezius than the CON. [Pyruvate] was overall significantly lower in WAD, and with lactate it showed another time-pattern throughout the test. In the multivariate regression analysis of pain intensity [5-HT] was the strongest regressor and positively correlated with pain intensity in WAD. In addition, blood flow, [pyruvate], and [potassium] influenced the pain intensity in a complex time dependent way. These findings may indicate that peripheral nociceptive processes are activated in WAD with generalized hypersensitivity for pressure and they are not identical with those reported in chronic work-related trapezius myalgia, which could indicate different pain mechanisms.

Objective: The aims of this study were: (i) to classify subgroups according to the degree of pain intensity, depression, and catastrophizing, and investigate distribution in a group of patients with chronic whiplash-associated disorders; and (ii) to investigate how these subgroups were distributed and inter-related multivariately with respect to consequences such as health and quality of life outcome measures.

Design: Descriptive cross-sectional study.

Patients: A total of 275 consecutive chronic pain patients with whiplash-associated disorders who were referred to a university hospital.

Methods: The following data were obtained by means of self-report questionnaires: pain intensity in neck and shoulders, background history, Beck Depression Inventory, the catastrophizing scale of Coping Strategy Questionnaire, Life Satisfaction Checklist, the SF-36 Health Survey, and the EuroQol.

Results: Principal component analysis was used to recognize subgroups according to the degree of pain intensity, depression, and catastrophizing. These subgroups have specific characteristics according to perceived health and quality of life, and the degree of depression appears to be the most important influencing factor.

Conclusion: From a clinical point of view, these findings indicate that it is important to assess patients for intensity of pain, depression, and catastrophizing when planning a rehabilitation programme. Such an evaluation will help individualize therapy and intervention techniques so as to optimize the efficiency of the programme.

Objectives: This study analyses the relationships between pain intensity and other aspects of health commonly used to assess disease activity and disability in early rheumatoid arthritis and examines whether such relationships were different between women and men.

Subjects and methods: This study included the 189 patients (69% women) with early RA (symptoms <12 months at diagnosis) still remaining in the Swedish TIRA cohort 5 years after inclusion. Disease activity and disability was assessed 3, 6, 12, 18, 24, 36, 48, and 60 months (M0-M60) after inclusion by erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), number of swollen and tender joints, physicians global assessment of disease activity (PGA), grip force average over 10 seconds (Grippit), Grip Ability Test (GAT), Signals of Functional Impairment (SOFI) in hand, lower limb and upper limb, Health Assessment Questionnaire (HAQ), and pain intensity measured with a visual analogue scale (VAS). The variables were divided into meaningful blocks according to the correlation structure in a principal component analysis (PCA) at M60. Using hierarchical partial least squares (PLS) analyses, this study investigated the blocks cross-sectionally to test for correlations with pain intensity at M0 and M60. The blocks at M0 were also used as predictors of pain intensity at M60 in a hierarchical PLS.

Results: The strongest relationship was found between pain intensity and the second block, consisting of HAQ and SOFI-lower limb at the cross-sectional analyses in both women and men. The block representing disease activity (i.e., ESR, CRP, PGA, and swollen and tender joints) had the weakest relation to pain intensity. According to the longitudinal analyses, the disease activity variables (block 1) at M0 had the strongest relationship to pain intensity at M60 in men. In contrast, HAQ and SOFI-lower limb (block 2) at M0 had a strong relation to pain intensity in women.

We conducted a prospective randomized study to investigate predictive factors for short- and long-term outcome of anterior cervical decompression and fusion (ACDF) as measured by current pain intensity on the Visual Analogue Scale (VAS) and by disability using the Neck Disability Index (NDI). Current understanding about how preoperative and short-term outcome data predict long-term outcome is sparse, and there are few studies involving analysis of short-term follow-up using multivariate approaches with quantification of the relative importance of each variable studied. A total of 95 patients were randomly allocated for ACDF with the cervical intervertebral fusion cage or the Cloward procedure. The mean follow-up time was 19 months (range 12-24) for short-term follow-up and 76 months (range 56-94 months) for long-term. Background factors, radiologically detected findings, physiological measurements, treatment type, pain, and disability were used as potential predictors. Multivariate statistical analysis by projection to latent structures was used to investigate predictors of importance for short- and long-term outcome of ACDF. A "preoperative" low disability and pain intensity, non-smoking status, male sex, good hand strength, and an active range of motion (AROM) in the neck were significant predictors for good short- and long-term outcomes. The short-term outcome data were better at predicting long-term outcome than were baseline data. Radiologically detected findings and surgical technique used were mainly insignificant as predictors. We suggest that the inclusion criteria for ACDF should be based on a bio-psycho-social model including NDI. NDI may also be regarded as an important outcome measurement in evaluation of ACDF.

Objective: The main aims of this study were: (i) to determine, for chronic whiplash-associated disorders, whether widespread pain has more severe consequences for other symptoms and different aspects of perceived health than does local/regional pain; (ii) to investigate whether pain, depression, and symptoms not directly related to pain are intercorrelated and to what extent these symptoms correlate with catastrophizing according to the Coping Strategy Questionnaire.

Design: Descriptive cross-sectional study.

Patients: A total of 275 consecutive chronic pain patients with whiplash-associated disorders who were referred to a university hospital.

Methods: Background history, Beck Depression Inventory, Coping Strategy Questionnaire, Life Satisfaction Checklist, the SF-36 Health Survey and EuroQol were used to collect data.

Results: Spreading of pain was associated with negative consequences with respect to pain intensity and prevalence of other symptoms, life satisfaction/quality and general health. The subjects differ with respect to the presence of symptoms not directly related to pain. A minor part of the variation in Back Depression Inventory was explained by direct aspects of pain, indicating that, to some extent, generalization of pain is related to catastrophizing thoughts.

Conclusion: Widespread pain was associated with negative consequences with respect to pain intensity, prevalence of other symptoms including depressive symptoms, some aspects of coping, life satisfaction and general health.

The mechanisms behind the development of work-related trapezius pain are suggested to involve both peripheral and central components, but the specific contribution of alterations in muscle nociceptive and other substances is not clear. Female patients with chronic trapezius myalgia (N=19, TM) and female controls (N=20, CON) were studied at rest, during 20 min repetitive low-force exercise and recovery, and had their interstitial concentrations of potassium (K+), lactate dehydrogenase (LDH), interleukin-6 (IL-6) and collagen turnover determined in the trapezius muscle by the microdialysis technique. K+ levels were at all time points higher in TM than in CON (P<0.0001). Baseline levels of LDH and IL-6 were similar in both groups. In response to exercise pain intensity, rated perceived exertion, and the concentrations of K+, LDH and IL-6 increased significantly in both groups. [K+] immediately decreased to baseline levels in CON but remained elevated during the first 20 min of recovery in TM (P<0.01) whereafter it returned to baseline level. In all subjects taken together mean [K+] correlated negatively with pressure pain threshold of trapezius (P<0.001), positively with mean pain intensity VAS (P<0.001) and mean perceived exertion (P<0.001). Rises in muscle LDH and IL-6 as well as the anabolic ratio for collagen type I was not significantly different between groups. In conclusion, patients with chronic pain in the trapezius muscle had increased levels of interstitial potassium. This finding could be causally related to myalgia or secondary to pain due to deconditioned muscle or altered muscle activity pattern. © 2005 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.