Decision Support for Managing Common Musculoskeletal Pain Disorders: Development of a Case-Based Reasoning Application.

BACKGROUND: Common interventions for musculoskeletal pain disorders either lack evidence to support their use or have small to modest or short-term effects. Given the heterogeneity of patients with musculoskeletal pain disorders, treatment guidelines and systematic reviews have limited transferability to clinical practice. A problem-solving method in artificial intelligence, case-based reasoning (CBR), where new problems are solved based on experiences from past similar problems, might offer guidance in such situations. OBJECTIVE: This study aims to use CBR to build a decision support system for patients with musculoskeletal pain disorders seeking physiotherapy care. This study describes the development of the CBR system SupportPrim PT and demonstrates its ability to identify similar patients. METHODS: Data from physiotherapy patients in primary care in Norway were collected to build a case base for SupportPrim PT. We used the local-global principle in CBR to identify similar patients. The global similarity measures are attributes used to identify similar patients and consisted of prognostic attributes. They were weighted in terms of prognostic importance and choice of treatment, where the weighting represents the relevance of the different attributes. For the local similarity measures, the degree of similarity within each attribute was based on minimal clinically important differences and expert knowledge. The SupportPrim PT's ability to identify similar patients was assessed by comparing the similarity scores of all patients in the case base with the scores on an established screening tool (the short form Örebro Musculoskeletal Pain Screening Questionnaire [ÖMSPQ]) and an outcome measure (the Musculoskeletal Health Questionnaire [MSK-HQ]) used in musculoskeletal pain. We also assessed the same in a more extensive case base. RESULTS: The original case base contained 105 patients with musculoskeletal pain (mean age 46, SD 15 years; 77/105, 73.3% women). The SupportPrim PT consisted of 29 weighted attributes with local similarities. When comparing the similarity scores for all patients in the case base, one at a time, with the ÖMSPQ and MSK-HQ, the most similar patients had a mean absolute difference from the query patient of 9.3 (95% CI 8.0-10.6) points on the ÖMSPQ and a mean absolute difference of 5.6 (95% CI 4.6-6.6) points on the MSK-HQ. For both ÖMSPQ and MSK-HQ, the absolute score difference increased as the rank of most similar patients decreased. Patients retrieved from a more extensive case base (N=486) had a higher mean similarity score and were slightly more similar to the query patients in ÖMSPQ and MSK-HQ compared with the original smaller case base. CONCLUSIONS: This study describes the development of a CBR system, SupportPrim PT, for musculoskeletal pain in primary care. The SupportPrim PT identified similar patients according to an established screening tool and an outcome measure for patients with musculoskeletal pain.

Acceptance and use of a clinical decision support system in musculoskeletal pain disorders - the SupportPrim project.

BACKGROUND: We have developed a clinical decision support system (CDSS) based on methods from artificial intelligence to support physiotherapists and patients in the decision-making process of managing musculoskeletal (MSK) pain disorders in primary care. The CDSS finds the most similar successful patients from the past to give treatment recommendations for a new patient. Using previous similar patients with successful outcomes to advise treatment moves management of MSK pain patients from one-size fits all recommendations to more individually tailored treatment. This study aimed to summarise the development and explore the acceptance and use of the CDSS for MSK pain patients. METHODS: This qualitative study was carried out in the Norwegian physiotherapy primary healthcare sector between October and November 2020, ahead of a randomised controlled trial. We included four physiotherapists and three of their patients, in total 12 patients, with musculoskeletal pain in the neck, shoulder, back, hip, knee or complex pain. We conducted semi-structured telephone interviews with all participants. The interviews were analysed using the Framework Method. RESULTS: Overall, both the physiotherapists and patients found the system acceptable and usable. Important findings from the analysis of the interviews were that the CDSS was valued as a preparatory and exploratory tool, facilitating the therapeutic relationship. However, the physiotherapists used the system mainly to support their previous and current practice rather than involving patients to a greater extent in decisions and learning from previous successful patients. CONCLUSIONS: The CDSS was acceptable and usable to both the patients and physiotherapists. However, the system appeared not to considerably influence the physiotherapists' clinical reasoning and choice of treatment based on information from most similar successful patients. This could be due to a smaller than optimal number of previous patients in the CDSS or insufficient clinical implementation. Extensive training of physiotherapists should not be underestimated to build understanding and trust in CDSSs.

SupportPrim-a computerized clinical decision support system for stratified care for patients with musculoskeletal pain complaints in general practice: study protocol for a randomized controlled trial.

BACKGROUND: Musculoskeletal disorders represented 149 million years lived with disability world-wide in 2019 and are the main cause of years lived with disability worldwide. Current treatment recommendations are based on "one-size fits all" principle, which does not take into account the large degree of biopsychosocial heterogeneity in this group of patients. To compensate for this, we developed a stratified care computerized clinical decision support system for general practice based on patient biopsychosocial phenotypes; furthermore, we added personalized treatment recommendations based on specific patient factors to the system. In this study protocol, we describe the randomized controlled trial for evaluating the effectiveness of computerized clinical decision support system for stratified care for patients with common musculoskeletal pain complaints in general practice. The aim of this study is to test the effect of a computerized clinical decision support system for stratified care in general practice on subjective patient outcome variables compared to current care. METHODS: We will perform a cluster-randomized controlled trial with 44 general practitioners including 748 patients seeking their general practitioner due to pain in the neck, back, shoulder, hip, knee, or multisite. The intervention group will use the computerized clinical decision support system, while the control group will provide current care for their patients. The primary outcomes assessed at 3 months are global perceived effect and clinically important improvement in function measured by the Patient-Specific Function Scale (PSFS), while secondary outcomes include change in pain intensity measured by the Numeric Rating Scale (0-10), health-related quality of life (EQ-5D), general musculoskeletal health (MSK-HQ), number of treatments, use of painkillers, sick-leave grading and duration, referral to secondary care, and use of imaging. DISCUSSION: The use of biopsychosocial profile to stratify patients and implement it in a computerized clinical decision support system for general practitioners is a novel method of providing decision support for this patient group. The study aim to recruit patients from May 2022 to March 2023, and the first results from the study will be available late 2023. TRIAL REGISTRATION: The trial is registered in ISRCTN 11th of May 2022: 14,067,965.

Group-delivered cognitive behavioural therapy versus waiting list in the treatment of insomnia in primary care: study protocol for a pragmatic, multicentre randomized controlled trial.

BACKGROUND: Insomnia is common in the general population and is a risk factor for ill-health, which highlights the importance of treating insomnia effectively and cost-efficiently. Cognitive-behavioural therapy for insomnia (CBT-I) is recommended as first-line treatment due to its long-term effectiveness and few side-effects, but its availability is limited. The aim of this pragmatic, multicentre randomized controlled trial is to investigate the effectiveness of group-delivered CBT-I in primary care compared to a waiting-list control group. METHODS: A pragmatic multicentre randomized controlled trial will be conducted with about 300 participants recruited across 26 Healthy Life Centres in Norway. Participants will complete online screening and provide consent before enrolment. Those who meet the eligibility criteria will be randomized to a group-delivered CBT-I or to a waiting list according to a 2:1 ratio. The intervention consists of four two-hour sessions. Assessments will be performed at baseline, 4 weeks, 3- and 6 months post-intervention, respectively. The primary outcome is self-reported insomnia severity at 3 months post-intervention. Secondary outcomes include health-related quality of life, fatigue, mental distress, dysfunctional beliefs and attitudes about sleep, sleep reactivity, 7-day sleep diaries, and data obtained from national health registries (sick leave, use of relevant prescribed medications, healthcare utilization). Exploratory analyses will identify factors influencing treatment effectiveness, and we will conduct a mixed-method process evaluation to identify facilitators and barriers of participants' treatment adherence. The study protocol was approved by the Regional Committee for Medical and Health Research ethics in Mid-Norway (ID 465241). DISCUSSION: This large-scale pragmatic trial will investigate the effectiveness of group-delivered cognitive behavioural therapy versus waiting list in the treatment of insomnia, generating findings that are generalizable to day-to-day treatment of insomnia in interdisciplinary primary care services. The trial will identify those who would benefit from the group-delivered therapy, and will investigate the rates of sick leave, medication use, and healthcare utilization among adults who undergo the group-delivered therapy. TRIAL REGISTRATION: The trial was retrospectively registered in the ISRCTN registry (ISRCTN16185698).

The joint effect of sleep duration and insomnia symptoms on the risk of recurrent spinal pain: The HUNT study.

Although sleep quantity and quality appear to be interrelated, most previous studies have considered sleep duration and insomnia symptoms as distinct entities. We therefore examined whether there is a joint effect of sleep duration and long-term changes in insomnia symptoms on the risk of recurrent chronic spinal pain. We performed a prospective study of 8,788 participants who participated in three surveys over ∼22 years and reported chronic spinal pain at the first, second, or both surveys. Adjusted risk ratios (RRs) were calculated for the risk of recurrent spinal pain at the last survey associated with self-reported sleep duration at the first survey and changes in insomnia symptoms between the two first surveys. Compared to participants with normal sleep duration (7-9 h) and no insomnia symptoms at the two first surveys, participants with insomnia symptoms over the same period had RRs of spinal pain of 1.33 (95% CI 1.26-1.41) in the last survey if they reported normal sleep duration and 1.50 (95% CI 1.34-1.67) if they reported short sleep (≤6 h). The corresponding RRs for spinal pain for participants who improved their sleep symptoms were 1.09 (95% CI 1.00-1.19) for those with normal sleep and 1.13 (95% CI 0.88-1.45) for those with short sleep. In conclusion, people who reported insomnia symptoms over ∼10 years in combination with short sleep had a particularly increased risk of recurrent spinal pain. Improvement in insomnia symptoms was associated with a favorable prognosis.

Patient characteristics and outcome in three different working models of home-based rehabilitation: a longitudinal observational study in primary health care in Norway.

BACKGROUND: The organisation of health care services for older adults varies within and between countries. In Norway, primary care physiotherapy services offer home-based rehabilitation to older adults. The aim of this study was to compare patients' characteristics and treatment outcomes in three working models of home-based rehabilitation. METHODS: Patients referred to home-based rehabilitation in a large municipality in Norway were invited to participate in this prospective observational study. The three working models, early intervention, reablement and regular physiotherapy, were organised according to the patients' function and degree of independence. The older adults (≥ 65 years) were allocated to the different models by either a multidisciplinary group of health care personnel or by direct referral. Patients' demographic and clinical characteristics, including physical function (Patient-specific functional scale, PSFS), physical performance (Short Physical Performance Battery, SPPB) and health-related quality of life (EQ-5D) were registered at baseline and follow-up (maximum 6 months after baseline). One-way ANOVA was used to analyse group differences in clinical characteristics and paired t-tests to analyse changes from baseline to follow-up. RESULTS: In total, 603 and 402 patients (median (interquartile range) age: 84 (77-88) years) completed baseline and follow-up assessments, respectively. Patients in all three working models had an increased risk for functional decline. Patients receiving early intervention (n = 62) had significantly (p < 0.001) better physical performance and health-related quality of life (SPPB mean 7.9, SD 2.7; EQ-5D:mean 0.59, SD 0.19), than patients receiving reablement (n = 132) (SPPB: mean 5.5, SD 2.6; EQ-5D: mean 0.50, SD 0.15) and regular physiotherapy (n = 409) (SPPB: mean 5.6, SD 2.8; EQ-5D: mean 0.41, SD 0.22). At follow-up, the three working models showed significantly improvements in physical function (PSFS: mean change (95 % CI): 2.5 (1.9 to 3.2); 1.8 (0.5 to 3.1); 1.7 (0.8 to 2.6), for regular physiotherapy, reablement, and early intervention, respectively). Patients receiving regular physiotherapy and reablement also significantly improved physical performance and health-related quality of life. CONCLUSIONS: While older adults receiving reablement and regular physiotherapy showed similar patient characteristics and treatment outcomes, early intervention identified older patients at risk of functional decline at an earlier stage. These results are relevant for policy makers when designing and improving prevention and rehabilitation strategies in primary health care.

Subtypes of insomnia and the risk of chronic spinal pain: the HUNT study.

OBJECTIVE: To examine the association between subtypes of insomnia and the risk of chronic spinal pain. METHODS: The study comprised 16,401 participants without chronic spinal pain at baseline who were followed for ∼11 years. People were categorized into 'no insomnia symptoms', 'subthreshold insomnia', and 'insomnia'. Insomnia was defined according to the diagnostic classification system requiring both daytime and nighttime symptoms, and further categorized into subtypes based on nighttime symptoms (ie, sleep onset latency [SOL-insomnia], wake after sleep onset [WASO-insomnia], early morning awakening [EMA-insomnia], or combinations of these). Subthreshold insomnia comprised those with only daytime impairment or one or more nighttime symptoms. Chronic spinal pain was defined as pain in either 'neck', 'low back', or 'upper back', or a combination of these. RESULTS: In multivariable regression analysis using people without insomnia as reference, people with subthreshold insomnia or insomnia had relative risks (RRs) of chronic spinal pain of 1.29 (95% confidence interval [CI] 1.21-1.38) and 1.50 (95% CI 1.34-1.68), respectively. The RRs for people with one nighttime symptom were 1.30 (95% CI 0.83-2.05) for WASO-insomnia, 1.32 (95% CI 1.06-1.65) for EMA-insomnia, and 1.70 (95% CI 1.32-2.18) for SOL-insomnia, respectively. Combinations of nighttime insomnia symptoms gave RRs from 1.45 (95% CI 1.08-1.94) for WASO + EMA-insomnia to 1.72 (95% CI 1.36-2.19) for all nighttime symptoms (SOL + WASO + EMA-insomnia). CONCLUSIONS: These findings suggest that the risk of chronic spinal pain is highest among persons with insomnia subtypes characterized by sleep onset latency or among those having insomnia symptoms in all parts of the sleep period.

Prognostic ability of STarT Back Screening Tool combined with work-related factors in patients with low back pain in primary care: a prospective study.

OBJECTIVE: Primary care screening tools for patients with low back pain may improve outcome by identifying modifiable obstacles for recovery. The STarT Back Screening Tool (SBST) consists of nine biological and psychological items, with less focus on work-related factors. We aimed at testing the prognostic ability of SBST and the effect of adding items for future and present work ability. METHODS: Prospective observational study in patients (n=158) attending primary care physical therapy for low back pain. The prognostic ability of SBST and the added prognostic value of two work items; expectation for future work ability and current work ability, were calculated for disability, pain and quality of life outcome at 3 months follow-up. The medium and high-risk group in the SBST were collapsed in the analyses due to few patients in the high-risk group. The prognostic ability was assessed using the explained variance (R2) of the outcomes from univariable and multivariable linear regression and beta values with 95% CIs were used to assess the prognostic value of individual items. RESULTS: The SBST classified 107 (67.7%) patients as low risk and 51 (32.3%) patients as medium/high risk. SBST provided prognostic ability for disability (R2=0.35), pain (R2=0.25) and quality of life (R2=0.28). Expectation for return to work predicted outcome in univariable analyses but provided limited additional prognostic ability when added to the SBST. Present work ability provided additional prognostic ability for disability (ß=-2.5; 95% CI=-3.6 to -1.4), pain (ß=-0.2; 95% CI=-0.5 to -0.002) and quality of life (ß=0.02; 95% CI=0.001 to 0.04) in the multivariable analyses. The explained variance (R2) when work ability was added to the SBST was 0.60, 0.49 and 0.47 for disability, pain and quality of life, respectively. CONCLUSIONS: Adding one work ability item to the SBST gives additional prognostic information across core outcomes. Clinical trial number: NCT03626389.

Recovery trajectories in common musculoskeletal complaints by diagnosis contra prognostic phenotypes.

BACKGROUND: There are large variations in symptoms and prognostic factors among patients sharing the same musculoskeletal (MSK) diagnosis, making traditional diagnostic labelling not very helpful in informing treatment or prognosis. Recently, we identified five MSK phenotypes across common MSK pain locations through latent class analysis (LCA). The aim of this study was to explore the one-year recovery trajectories for pain and functional limitations in the phenotypes and describe these in relation to the course of traditional diagnostic MSK groups. METHODS: We conducted a longitudinal observational study of 147 patients with neck, back, shoulder or complex pain in primary health care physiotherapy. Data on pain intensity and function were collected at baseline (week 0) and 1, 2, 3, 4, 6, 8, 12, 26 and 52 weeks of follow up using web-based questionnaires and mobile text messages. Recovery trajectories were described separately for the traditional diagnostic MSK groups based on pain location and the same patients categorized in phenotype groups based on prognostic factors shared among the MSK diagnostic groups. RESULTS: There was a general improvement in function throughout the year of follow-up for the MSK groups, while there was a more modest decrease for pain intensity. The MSK diagnoses were dispersed across all five phenotypes, where the phenotypes showed clearly different trajectories for recovery and course of symptoms over 12 months follow-up. This variation was not captured by the single trajectory for site specific MSK diagnoses. CONCLUSION: Prognostic subgrouping revealed more diverse patterns in pain and function recovery over 1 year than observed in the same patients classified by traditional diagnostic groups and may better reflect the diversity in recovery of common MSK disorders.

Associations between treatment goals, patient characteristics, and outcome measures for patients with musculoskeletal disorders in physiotherapy practice.

BACKGROUND: Goal setting is linked to person-centred care and is a core component in physiotherapy, but the associations between goal classes, patient characteristics and outcome measures for musculoskeletal disorders has not been investigated. The study's purpose was to examine 1) how goals used in clinical practice for patients with musculoskeletal disorders (MSD) are distributed in classes based on ICF, 2) if goal classes were associated with patient characteristics and 3) whether goal classes were associated with treatment outcome. METHODS: Data analysis from a longitudinal observational study (N = 2591). Goals were classified in symptom, function/structure, activity/participation and non-classifiable. Associations between patient characteristics and goal classes were examined using x2 and one-way ANOVA. Association between goal classes and outcomes were examined using multiple logistic and linear regression models. Outcomes are reported at 3 months or end of treatment if prior to 3 months. RESULTS: There was a high variability in goals used for patients with MSD. 17% had symptom goals, 32.3% function/structure, 43.4% activity/participation and 7.4% non-classifiable goals. We found significant associations between goal classes and age, gender, severity, region of pain/diagnosis and emotional distress (all p < .001). Activity/participation goals were associated with better outcomes on GPE (OR 1.80, 95% CI 1.23-2.66). Non-classifiable goal was associated with poorer outcomes on pain intensity (B .87, 95% CI .32-1.43). CONCLUSION: There is an association between goal classes and patient characteristics. Including activity/participation in the main goal was associated with better outcomes for GPE and having a non-classifiable goal was associated with poorer outcomes for pain intensity. TRIAL REGISTRATION: The project is approved by the Regional committee for Medical and Health Research Ethics in Norway (REC no. 2013/2030).  https://clinicaltrials.gov/ct2/show/NCT03626389 .

Genetic variants related to physical activity or sedentary behaviour: a systematic review.

BACKGROUND: Research shows that part of the variation in physical activity and sedentary behaviour may be explained by genetic factors. Identifying genetic variants associated with physical activity and sedentary behaviour can improve causal inference in physical activity research. The aim of this systematic review was to provide an updated overview of the evidence of genetic variants associated with physical activity or sedentary behaviour. METHODS: We performed systematic literature searches in PubMed and Embase for studies published from 1990 to April 2020 using keywords relating to "physical activity", "exercise", "sedentariness" and "genetics". Physical activity phenotypes were either based on self-report (e.g., questionnaires, diaries) or objective measures (e.g., accelerometry, pedometer). We considered original studies aiming to i) identify new genetic variants associated with physical activity or sedentary behaviour (i.e., genome wide association studies [GWAS]), or ii) assess the association between known genetic variants and physical activity or sedentary behaviour (i.e., candidate gene studies). Study selection, data extraction, and critical appraisal were carried out by independent researchers, and risk of bias and methodological quality was assessed for all included studies. RESULTS: Fifty-four out of 5420 identified records met the inclusion criteria. Six of the included studies were GWAS, whereas 48 used a candidate gene approach. Only one GWAS and three candidate gene studies were considered high-quality. The six GWAS discovered up to 10 single nucleotide polymorphisms (SNPs) associated with physical activity or sedentariness that reached genome-wide significance. In total, the candidate gene studies reported 30 different genes that were associated (p < 0.05) with physical activity or sedentary behaviour. SNPs in or close to nine candidate genes were associated with physical activity or sedentary behaviour in more than one study. CONCLUSION: GWAS have reported up to 10 loci associated with physical activity or sedentary behaviour. Candidate gene studies have pointed to some interesting genetic variants, but few have been replicated. Our review highlights the need for high-quality GWAS in large population-based samples, and with objectively assessed phenotypes, in order to establish robust genetic instruments for physical activity and sedentary behaviour. Furthermore, consistent replications in GWAS are needed to improve credibility of genetic variants. TRIAL REGISTRATION: Prospero CRD42019119456 .

Profile of children referred to primary health care physiotherapy: a longitudinal observational study in Norway.

BACKGROUND: Physiotherapy services are an important part of the primary health care services for children, serving a broad spectrum of children referred from different sources and for a variety of reasons. There is limited knowledge about their characteristics and outcome. The aim of this study was to describe the profile, i.e. referral patterns, baseline demographical and clinical characteristics, as well as treatment outcome at follow-up 6 months after baseline, of children receiving physiotherapy in primary health care. METHODS: Children referred to primary health care physiotherapy in a large municipality in Norway were invited to participate in this longitudinal observational study. The children's demographics, referral sources, causes of referral, functional diagnoses, influence on their daily activities, main goals and planned treatments were registered at baseline. Goal attainment and treatment compliance were registered at follow-up maximum 6 months after baseline. RESULTS: The physiotherapists registered baseline characteristics for 148 children. Parent-reported data at baseline were available for 101 (68.2%) of these children. Children were mainly referred from child health care centres (n = 74; 50.0%), hospital (n = 25; 16.9%) and kindergarten (n = 22; 14.9%). The most frequent causes of referral were concerns for motor development (n = 50; 33.8%), asymmetry (n = 40; 27.0%) and orthopaedic conditions (n = 25; 16.9%). Eighty-one (54.7%) children were below the age of 1 year. There was partly agreement between causes of referral and the physiotherapists' functional diagnoses. Parents of 69 (71.1%) children reported that their child's daily activities were little to not at all affected by the problem or complaint for which they were referred. Follow-up data were registered for 64 children. The main treatment goal was achieved in 37 (57.8%) and partly achieved in 26 (40.6%) children and the treatment was carried out as planned in 55 (87.3%) children. CONCLUSIONS: The large variation in the profile of children receiving physiotherapy in a primary health care setting in Norway shows how primary health care physiotherapists can contribute to fulfil the broad purpose of the primary health care services. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03626389 . Registered on August 13th 2018 (retrospectively registered).

Subgroups of Long-Term Sick-Listed Based on Prognostic Return to Work Factors Across Diagnoses: A Cross-Sectional Latent Class Analysis.

Comorbidity is common among long-term sick-listed and many prognostic factors for return to work (RTW) are shared across diagnoses. RTW interventions have small effects, possibly due to being averaged across heterogeneous samples. Identifying subgroups based on prognostic RTW factors independent of diagnoses might help stratify interventions. The aim of this study was to identify and describe subgroups of long-term sick-listed workers, independent of diagnoses, based on prognostic factors for RTW. Latent class analysis of 532 workers sick-listed for eight weeks was used to identify subgroups based on seven prognostic RTW factors (self-reported health, anxiety and depressive symptoms, pain, self-efficacy, work ability, RTW expectations) and four covariates (age, gender, education, physical work). Four classes were identified: Class 1 (45% of participants) was characterized by favorable scores on the prognostic factors; Class 2 (22%) by high anxiety and depressive symptoms, younger age and higher education; Class 3 (16%) by overall poor scores including high pain levels; Class 4 (17%) by physical work and lack of workplace adjustments. Class 2 included more individuals with a psychological diagnosis, while diagnoses were distributed more proportionate to the sample in the other classes. The identified classes illustrate common subgroups of RTW prognosis among long-term sick-listed individuals largely independent of diagnosis. These classes could in the future assist RTW services to provide appropriate type and extent of follow-up, however more research is needed to validate the class structure and examine how these classes predict outcomes and respond to interventions.

Rigid head-neck responses to unpredictable perturbations in patients with long standing neck pain does not change with treatment.

In a previous study we have shown that patients with long standing non-specific neck-pain display more rigid neck movement behavior than controls in response to unpredictable perturbations. In the present study we investigated head/neck motor control in patients with neck-pain during a course of physiotherapy intervention and the associations with pain, neck disability and kinesiophobia. In this longitudinal observational study, 72 patients with non-specific neck-pain were exposed to unpredictable horizontal rotations by means of an actuated chair in three conditions; with a visual reference, and without vision with and without a cognitive task before first consultation with physiotherapist, after 2 weeks and 2 months of intervention. The neck movements were analyzed in the frequency domain to cover voluntarily and reflex controlled responses. Questionnaires encompassed Neck Disability Index, Tampa Scale of Kinesiophobia, and the Numerical Rating Scale for current pain. The results showed that the response pattern for the amplitudes of movement between head and trunk across frequencies did not change over time, whereas some changes in timing were found for some frequencies. Pain, neck disability, and kinesiophobia improved after intervention, but were not significantly associated with neck movement responses to perturbations across time or condition. Although physiotherapy intervention improved self-reported function, the rigid responses to unpredictable perturbations remained unchanged. This indicates altered function in reflex mediated control mechanisms, i.e., the vestibulocollic and the cervicocollic reflex systems that control the head in space and on the trunk. Future research should further investigate pain related changes in reflex systems and whether alterations in these systems are modifiable.

Novel approach towards musculoskeletal phenotypes.

BACKGROUND: The multidimensional array of clinical features and prognostic factors makes it difficult to optimize management within the heterogeneity of patients with common musculoskeletal pain. This study aimed to identify phenotypes across prognostic factors and musculoskeletal complaints. Concurrent and external validity were assessed against an established instrument and a new sample, respectively, and treatment outcome was described. METHODS: We conducted a longitudinal observational study of 435 patients (aged 18-67 years) seeking treatment for nonspecific complaints in the neck, shoulder, low back or multisite/complex pain in primary health care physiotherapy in Norway. Latent class analysis was used to identify phenotypes based on 11 common prognostic factors within four biopsychosocial domains; pain, beliefs and thoughts, psychological and activity and lifestyle. RESULTS: Five distinct phenotypes were identified. Phenotype 1 (n = 77, 17.7%) and 2 (n = 142, 32.6%) were characterized by the lowest scores across all biopsychosocial domains. Phenotype 2 showed somewhat higher levels of symptoms across the biopsychosocial domains. Phenotype 3 (n = 89, 20.5%) and 4 (n = 78, 17.9%) were more affected across all domains, but phenotype 3 and 4 had opposite patterns in the psychological and pain domains. Phenotype 5 (n = 49, 11.3%) were characterized by worse symptoms across all domains, indicating a complex phenotype. The identified phenotypes had good external and concurrent validity, also differentiating for the phenotypes in function and health-related quality of life outcome at 3-month follow-up. CONCLUSION: The phenotypes may inform the development of targeted interventions aimed at improving the treatment efficiency in patients with common musculoskeletal disorders. SIGNIFICANCE: This observational prospective study identified five distinct and clinically meaningful phenotypes based on biopsychosocial prognostic factors across common musculoskeletal pain. These phenotypes were independent of primary pain location, showed good external validity, and clear variation in treatment outcome. The findings are particularly valuable as they describe the heterogeneity of patients with musculoskeletal pain and points to a need for more targeted interventions in common musculoskeletal disorders to improve treatment outcome.

Longitudinal associations of kinematics and fear-avoidance beliefs with disability, work ability and pain intensity in persons with low back pain.

BACKGROUND: Impaired lumbar movement has cross-sectionally been associated with low back pain (LBP); however, the consequence of impaired movement on disability and pain in persons with LBP is poorly understood. Furthermore, fear-avoidance beliefs (FAB) may influence spinal movement, but the relation between fear-avoidance and kinematics is unclear. OBJECTIVES: To investigate the longitudinal associations of kinematics and FAB with disability, work ability and pain in patients with LBP. Further, to explore associations between FAB and kinematics. DESIGN: Prospective observational study. METHOD: Kinematic measures were performed on 44 persons with LBP at baseline, three and nine months. Motion sensors identified range-of-motion and velocity during a spinal flexion/extension. FAB, disability, work ability and pain were reported at all time points using questionnaires. RESULTS: Increased range-of-motion was weakly associated with less disability (-0.14 points, 95% CI -0.22 to -0.06). Velocity was not associated with disability, work ability or pain. Higher FAB of physical activity were associated with more disability (1.50 points, 95% CI 0.51 to 2.49) and pain (0.37 points, 95% CI 0.11 to 0.62). Higher work-related FAB was associated with lower work ability (-0.37 points, 95% CI -0.68 to -0.05). Moreover, higher FAB showed weak associations with lower velocity in the initial movement phase (-3.3°/s, 95% CI -6.1 to -0.5). CONCLUSIONS: Of the kinematic measures, only range-of-motion was related to disability. Higher FAB was weakly associated with all self-reported outcomes and with lower velocity only at the initial flexion phase. However, the magnitude of these associations suggest marginal clinical importance.

Frequency-dependent deficits in head steadiness in patients with nonspecific neck pain.

Motor control impairments are reported in patients with nonspecific neck pain but the particular deficits in underlying regulatory systems are not known. Head steadiness is controlled both by voluntary and reflex systems that are predominantly effective within different frequency intervals. The aim of the present study was to investigate within which frequency range(s) potential motor control deficits may reside. The ability to keep the head stationary in space in response to unpredictable perturbations was tested in 71 patients with nonspecific neck pain and 17 healthy controls. Participants were exposed to pseudorandom horizontal rotations across 10 superimposed frequencies (0.185-4.115 Hz) by means of an actuated chair in three conditions; with a visual reference, and without vision with, and without a cognitive task. Below 1 Hz, patients kept the head less stable in space compared to healthy controls. Between 1 and 2 Hz, the head was stabilized on the trunk in both groups. Patients kept the head more stable relative to the trunk than relative to space compared to healthy controls. This was interpreted as higher general neck muscle co-activation in patients, which may be explained by altered voluntary control, or/and upregulated gamma motor neuron activity which increases the contribution of reflex-mediated muscle activation. Alternatively, increased muscle activity is secondary to vestibular deficits.

Improvement in Work Ability, Psychological Distress and Pain Sites in Relation to Low Back Pain Prognosis: A Longitudinal Observational Study in Primary Care.

STUDY DESIGN: Prospective observational study pooled from two clinical cohorts. OBJECTIVE: To investigate the longitudinal relation between multisite pain, psychological distress, and work ability with disability, pain, and quality of life. SUMMARY OF BACKGROUND DATA: Knowledge of prognostic factors is essential for better management of patients with low back pain (LBP). All domains of the biopsychosocial model have shown prognostic value; however, clinical studies rarely incorporate all domains when studying treatment outcome for patients with LBP. METHODS: A total of 165 patients with nonspecific LBP seeking primary care physiotherapy were included. Mixed-effects models were used to estimate longitudinal relations between the exposure variables and concurrent measures of outcomes at baseline and 3 months. Logistic regression was used to estimate odds ratios for minimal important difference in outcome. RESULTS: Higher work ability was associated with less disability -2.6 (95% confidence interval [CI]: -3.3, -2.0), less pain: -0.4 (95% CI: -0.5, -0.3), and higher quality of life 0.03 (95% CI: 0.02, 0.04). Higher psychological distress and number of pain sites were associated with higher disability: 10.9 (95% CI: 7.7, 14.1) and 2.3 (95% CI: 1.4, 3.2) higher pain: 1.9 (95% CI: 1.3, 2.5) and 0.4 (95% CI: 0.2, 0.5), and lower quality of life: -0.1 (95% CI: -0.2, -0.1) and -0.02 (95% CI: -0.03, -0.01), respectively. Improvement in work ability showed consistent associations with successful outcome for disability (odds ratio [OR]: 4.8, 95% CI: 1.3, 18.1), pain (OR: 3.6, 95% CI: 1.1, 12.1), and quality of life (OR: 4.5, 95% CI: 1.4, 15.1) at 3 months. Reduced psychological distress was associated with improvement in pain only (OR 4.0, 95% CI: 1.3, 12.3). CONCLUSION: More pain sites, higher psychological distress, or lower work ability showed higher disability, more pain, and lower quality of life in patients with LBP. Only improvement in work ability was consistently related to successful outcomes. LEVEL OF EVIDENCE: 2.