Ottar Vasseljen

• PhD
• Professor at Norwegian University of Science and Technology

BACKGROUND: Specific stabilizing exercises activating deep local muscles in coordination with global muscles are recommended in the treatment of pregnancy-related lumbopelvic pain. Some studies have suggested that recruitment of the deepest abdominal muscle, transversus abdominis, is crucial in the development and improvement of lumbopelvic pain.OB...

We developed the SupportPrim PT clinical decision support system (CDSS) using the artificial intelligence method case-based reasoning to support personalised musculoskeletal pain management. The aim of this study was to evaluate the effectiveness of the CDSS for patients in physiotherapy practice. A cluster randomised controlled trial was conducted...

Objectives Previously, we reported that an inpatient multimodal occupational rehabilitation program (I-MORE) was more effective than outpatient Acceptance and Commitment Therapy (O-ACT) in reducing sickness absence and was cost-effective over a 24-month period. Here we present 7-years of follow-up on sick leave and the cost of lost production. Met...

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 recommendat...

This is a statistical Analysis Plan (SAP) for “SupportPrim – A computerized clinical decision support system for stratified care for patients with musculoskeletal pain complaints in general practice”. The SAP elaborates the statistics described in the published study protocol. The structure of this SAP follows the guidelines provided by Gamble et a...

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 recommendat...

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...

Purpose: To evaluate the cost-effectiveness and cost-benefit of inpatient multimodal occupational rehabilitation (I-MORE) compared to outpatient acceptance and commitment therapy (O-ACT) for individuals sick listed due to musculoskeletal- or common mental disorders during two-years of follow-up. Methods: We conducted an economic evaluation with...

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 o...

Background: Chronic musculoskeletal pain (CMP) is characterised by pain related to the muscles or the joints with a duration of three months or more and is associated with high symptomatic burden in patients in primary health care. CMP is commonly associated with impaired mental health, which may affect the rehabilitation process. The primary aim...

BACKGROUND Applying group-level evidence from guidelines to individual patients is challenging due to the great variation in symptoms in patients with musculoskeletal (MSK) pain complaints. A problem-solving method in artificial intelligence (AI), case-based reasoning (CBR), where new problems are solved based on experiences from past similar probl...

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 i...

Purpose There is a lack of results on long-term effects of return to work interventions. We previously reported that an inpatient multimodal occupational rehabilitation program (I-MORE) was more effective in reducing sickness absence and facilitating return to work (RTW) at 12 months follow-up compared to an outpatient program that consisted mainly...

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 it...

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...

Background Chronic musculoskeletal pain (CMP) affects daily life function and is the most prevalent disorder in primary health care. The primary objective was to examine demographic factors and pain characteristics associated with reduced health-related quality of life (HRQoL) among patients in primary care reporting CMP. Our secondary objective wa...

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...

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...

Objectives This study aimed to investigate whether inpatient multimodal occupational rehabilitation (I-MORE) reduces sickness absence (SA) more than outpatient acceptance and commitment therapy (O-ACT) among individuals with musculoskeletal and mental health disorders. Methods Individuals on sick leave (2-12 months) due to musculoskeletal or commo...

Objectives To assess changes in participants’ expectations about length of sick leave during Acceptance and Commitment Therapy (ACT)-based occupational rehabilitation, and whether the change in expectations was associated with future work participation. Methods Cohort study with 9 months follow-up including sick listed workers who took part in one...

This paper presents a method for developing case-based reasoning (CBR) application for discovering similar patients with non-specific musculoskeletal disorders (MSDs) and recommending treatment plans using previous experiences. From a medical perspective, MSD is a complex disorder as its cause is often bounded to a combination of physiological and...

This paper presents a method for developing case-based reasoning (CBR) application for discovering similar patients with non-specific musculoskeletal disorders (MSDs) and recommending treatment plans using previous experiences. From a medical perspective, MSD is a complex disorder as its cause is often bounded to a combination of physiological and...

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 whi...

Table S1. Data corresponding to the statistics and to the right axis in Figure 3 for gain according to the decimal logarithm on a linear scale.

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 unclea...

Objectives: To assess: (i) whether changes in the Fear-Avoidance Beliefs Questionnaire (FABQ) were greater for multicomponent inpatient rehabilitation vs outpatient cognitive behavioural therapy, and (ii) whether baseline scores and changes (pre- to post-intervention) in FABQ were associated with future work-participation. Methods: Individuals sick...

Background Physiotherapists (PTs) in primary health care manage patients with large variation in medical diagnosis, age, functional status, disability and prognosis. Lack of knowledge and systematically collected data from patients treated by PTs in primary health care has prompted this longitudinal observational physiotherapy project. This paper a...

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...

Objective: To investigate whether progressive resistance training using elastic resistance bands improves neck-related disability more than general physical exercise in multidisciplinary rehabilitation of chronic neck pain. Design: Researcher-blinded, randomized controlled trial. Methods: A total of 59 patients with non-specific, chronic neck...

As many similar symptoms are reported in fibromyalgia (FM) and chronic fatigue syndrome (CFS), underlying defcits may potentially also be similar. Postural disequilibrium reported in both conditions may thus be explained by similar deviations in postural control strategies. 75 females (25/group FM, CFS and control, age 19–49 years) performed 60 s o...

Processed data for quiet standing on amplitude (AMP) and frequency (MF) for the slow (RM) and fast (TR) components in the anteroposterior (AP) and mediolateral (ML) directions for the three conditions: with vision (QO), without vision (QCL), and with vision standing on a compliant surface (QP) for the three groups: control (0), chronic fatigue synd...

Purpose To explore the usefulness of the Readiness for return to work scale in individuals participating in occupational rehabilitation, by assessing the association between the scale and return to work (RTW), and comparing the scale to a question assessing individuals’ expectations about length of sick leave. Method Prospective cohort study with 9...

Purpose To assess effects of an inpatient multicomponent occupational rehabilitation program compared to less comprehensive outpatient rehabilitation on sickness absence in persons with musculoskeletal- or mental health disorders. Methods Randomized clinical trial with parallel groups. Participants were individuals 18–60 years old on sick-leave for...

Multidisciplinary biopsychosocial rehabilitation has been recommended for chronic low back pain (LBP), including physical exercise. However, which exercise‐modality that is most advantageous in multidisciplinary biopsychosocial rehabilitation is unclear. In this study, we investigated whether multidisciplinary biopsychosocial rehabilitation could b...

Purpose To evaluate effects on somatic and mental health of a multicomponent inpatient occupational rehabilitation program compared to a less comprehensive outpatient program in individuals on sick leave for musculoskeletal complaints or mental health disorders. Methods A randomized clinical trial with parallel groups. Participants were individuals...

Previous studies indicate that elastic resistance bands (ERB) can be a viable option to conventional resistance-training equipment (CRE) during single-joint resistance exercises, but their efficacy has not been established for several commonly used multiple-joint resistance exercises. Thus, we compared muscular activation levels in four popular mul...

Background Low back pain (LBP) is a common cause of disability and is ranked as the most burdensome health condition globally. Self-management, including components on increased knowledge, monitoring of symptoms, and physical activity, are consistently recommended in clinical guidelines as cost-effective strategies for LBP management and there is i...

Objectives This study aimed to investigate the prospective influence of multisite pain, depression, anxiety, self-rated health and pain-related disability on recovery from chronic low back pain (LBP). Setting The data is derived from the second (1995–1997) and third (2006–2008) wave of the Nord-Trøndelag Health Study (HUNT) in Norway. Participant...

Multidisciplinary biopsychosocial rehabilitation has been recommended for chronic low back pain (LBP), including physical exercise. However, which exercise modality that is most advantageous in multidisciplinary biopsychosocial rehabilitation is unclear. In this study, we investigated whether multidisciplinary biopsychosocial rehabilitation could b...

Introduction Chronic low back pain (LBP) is a major health problem worldwide. Multidisciplinary rehabilitation and exercise is recommended for the management of chronic LBP. However, there is a need to investigate effective exercise interventions that is available in clinics and as home-based training on a large scale. This article presents the des...

Objective To investigate the prognostic importance of a number of sensorimotor and psychological factors for global perceived effect (GPE) after physiotherapy in patients with neck pain. In addition to baseline values, change scores were used as independent variables to identify treatment-modifiable factors. Design Clinical cohort study. Setting...

Objectives: The aim of this study was to investigate whether sonography is a reliable tool for measuring deep abdominal muscle activation in different static arm positions while standing. Methods: Sonographic recordings were made of the transversus abdominis and obliquus internus abdominis in 4 different static arm positions that varied with reg...

Video S1. Test situation with actuated chair.

Video S2. Animation from real data of response to sinusoidal input signals in ascending frequency. Magnitudes are exaggerated for visualization and do not correspond to magnitudes of chair motion in the experiment.

This study repeats the experimental protocol for investigation of head stabilization in healthy humans, described by Keshner and Peterson (1995) but with a modification of the analysis. Head movements were considered with respect to the room instead of relative to the trunk. The aim was to investigate the approximate contribution of reflex and volu...

Background Low back and neck pain are commonly reported in the general population and represent frequent causes for health care consultations. The main aim of this study was to describe the determinants of health care contact during a 1-year period in a general population with recent onset spinal pain. Methods From 9056 participants in a general h...

Neck pain is associated with several alterations in neck motion and motor control. Previous studies have investigated single constructs of neck motor control, while few have applied a comprehensive set of tests to investigate cervical motor control. This comparative cross- sectional study aimed to investigate different motor control constructs in n...

Background: Neck pain is associated with several alterations in neck motion and motor control, but most of the findings are based on cross-sectional studies. Objective: The aim of this study was to investigate associations between changes in neck motion and motor control, and changes in neck pain and disability in physiotherapy patients during a...

Laser beams have been applied in many human motion research contexts to project movements in specific motor tasks. Currently, there are no objective analysis methods for laser projection recordings. The principal aim of this study was to investigate the feasibility of quantifying motion by applying frame differencing and image analysis methods to v...

Question: Are there different effects of home exercises and supervised exercises on pain and disability for people with subacromial impingement? Design: Randomised trial with two treatment arms, concealed allocation, blinded assessment of some outcomes, and intention-to-treat analysis. Participants: Forty-six patients with subacromial impingem...

Artus M, van der Windt DA, Jordan KP, Hay EM: Low back pain symptoms show a similar pattern of improvement following a wide range of primary care treatments: a systematic review of randomized clinical trials. Rheumatology 49(12), 2346-56, 2010 Participants General population (GP): As part of a large Norwegian population survey we screened 9056 pers...

Aerobic endurance is an important aspect of physical fitness that enables individuals living with HIV to endure in the work place as well as in agricultural operations in order to earn a living and improve their quality of life. However, despite high HIV prevalence rates, the aerobic endurance status of young Malawians living with HIV remains unkno...

Background Chronic pain in the neck and low back is highly prevalent. Although heritable components have been identified, knowledge about generational transmission of spinal pain between parents and their adult offspring is sparse.Methods This study examined the intergenerational association of spinal pain using data from 11,081 parent–offspring tr...

Background: Long-term sick leave has considerably negative impact on the individual and society. Hence, the need to identify effective occupational rehabilitation programs is pressing. In Norway, group based occupational rehabilitation programs merging patients with different diagnoses have existed for many years, but no rigorous evaluation has be...

Background and purpose: Activation of transversus abdominis and fear avoidance beliefs have both been related to low back pain (LBP). This exploratory study aims to investigate associations between fear avoidance beliefs at baseline and deep abdominal muscle activation after an 8-week period of supervised exercises for chronic LBP. Methods: A co...

In this prospective cohort study we aimed to describe the natural course of acute neck and low back pain in a general population of Norway. We screened 9056 subjects aged 20-67years who participated in a general health survey for a new episode of neck or low back pain the previous month. The screening identified 219 subjects who formed the cohort f...

Objectives: To evaluate two different therapeutic exercise regimens in patients with patellofemoral pain syndrome (PFPS). Design: Multicentre, randomised controlled clinical trial. Setting: Three primary healthcare physiotherapy clinics. Participants: Forty-two patients with PFPS were assigned at random to an experimental group or a control...

To examine if pre-injury health-related factors are associated with the subsequent report of whiplash, and more specifically, both whiplash and neck pain. Longitudinal population study of 40,751 persons participating in two consecutive health surveys with 11 years interval. We used logistic regression to estimate odds ratio (OR) for reporting whipl...

A randomized controlled trial. To investigate feed-forward activation or timing of abdominal muscle activation in response to rapid shoulder flexion after 8 weeks with core stability exercises, sling exercises, or general exercises in chronic nonspecific low back pain (LBP) patients. Delayed onset in abdominal muscles has been associated with LBP....

To investigate associations between deep abdominal muscle activation and long-term pain outcome in chronic non-specific low back pain (LBP). Recruitment of transversus abdominis and obliquus internus abdominis during the abdominal drawing-in manoeuvre was recorded by B-mode ultrasound and anticipatory onset of deep abdominal muscle activity with M-...

Is there any difference between the effect of therapeutic ultrasound and antibiotics (amoxicillin) on pain and congestion for acute bacterial rhinosinusitis in the short-term? Is there any difference in patient satisfaction, preferred future intervention, side-effects and relapses in the long-term? A randomised trial with concealed allocation and i...

The aim of this study was to assess changes in deep abdominal muscle function after 8 weeks of exercise in chronic low back pain patients. Patients (n = 109) were randomized to specific ultrasound guided, sling or general exercises. Contraction thickness ratio in transversus abdominis (TrA), obliquus internus (OI) and externus (OE), and TrA lateral...

Exercise benefits patients with chronic nonspecific low back pain; however, the most effective type of exercise remains unknown. This study compared outcomes after motor control exercises, sling exercises, and general exercises for low back pain. This was a randomized controlled trial with a 1-year follow-up. The study was conducted in a primary ca...

To examine the association between leisure time physical exercise, body mass index (BMI), and risk of fibromyalgia (FM). A longitudinal study with baseline assessment of physical exercise (frequency, duration, and intensity) and BMI was used to explore the risk of having FM at 11-year followup in a large, unselected female population (n = 15,990) w...

While sensorimotor alterations have been observed in patients with neck pain, it is uncertain whether such changes distinguish whiplash-associated disorders from chronic neck pain without trauma. The aim of this study was to investigate head steadiness during isometric neck flexion in subjects with chronic whiplash-associated disorders (WAD), those...

Patients with whiplash associated disorders (WAD) have shown less accuracy in trajectory head motion compared to asymptomatic controls, which comply with clinical observations. The aim of this study was to investigate whether a trajectory head movement task can differ between WAD patients, chronic non-traumatic neck pain (CNP) patients and asymptom...

Persistent whiplash associated disorders (WAD) have been associated with alterations in kinesthetic sense and motor control. The evidence is however inconclusive, particularly for differences between WAD patients and patients with chronic non-traumatic neck pain. The aim of this study was to investigate motor control deficits in WAD compared to chr...

Delayed onset of muscle activity in abdominal muscles has been related to low back pain. To investigate this in larger clinical trials it would be beneficial if non-invasive and less cumbersome alternatives to intramuscular electromyography (EMG) were available. This study was designed to compare onset of muscle activity recorded by intramuscular E...

Question What is the effect of physiotherapy compared with a wait and see approach or corticosteroid injections for tennis elbow? Design Randomised controlled trial with concealed allocation, assessor blinding, and intention-totreat analysis. Setting Community setting in Australia. Participants 198 respondents to advertisements of the trial, age...

Background: Delayed anticipatory muscle activity response in deep abdominal and back muscles has been observed in patients with low back pain, indicative of a pathological condition. Muscle activity onset is traditionally recorded by intramuscular electromyography, but there is a need for a non-invasive and less cumbersome recording method in larg...

Unlabelled: This study extends the concept of tension, in part by observing changes in tension during the workday, to identify episodes causing elevated tension and relate them to bodily responses. Methods Both questionnaires and qualitative interviews were used to describe the tension concept. Tension was scored on a visual analogue scale (VAS) e...

Study Design. A multicenter, randomized, controlled trial with 1-year follow-up. Objectives. To compare the effect of manual therapy to exercise therapy in sick-listed patients with chronic low back pain ( > 8 wks). Summary and Background Data. The effect of exercise therapy and manual therapy on chronic low back pain with respect to pain, function...

A multicenter, randomized, controlled trial with 1-year follow-up. To compare the effect of manual therapy to exercise therapy in sick-listed patients with chronic low back pain (>8 wks). The effect of exercise therapy and manual therapy on chronic low back pain with respect to pain, function, and sick leave have been investigated in a number of st...

The study describes the patient population in private physiotherapy practice in a Norwegian urban community. All private practicing physiotherapists (n=87) in the area were sent a questionnaire and asked to fill in information about their patients per ultimo March 1998. Completed questionnaires were returned by 78 therapists (90 percent) and provid...

Perceived psychosocial and biomechanical exposures, individual factors and pain in the shoulder and neck were recorded in two groups of female service workers (healthcare and shopping centre workers). The jobs investigated were characterized by 'much' direct human relations, 'little' sitting and 'much' standing, and were light work by physiological...

Electromyographic activity of the upper trapezius muscles was recorded over the workday for two groups of service workers, shopping centre (n = 22) and healthcare workers (n = 44), both with low observed biomechanical exposure. Static and median EMG activity level, number of EMG gaps and gap time were determined. The variability of these variables...

OBJECTIVE: To investigate work technique in relation to work-related shoulder and neck pain (SNP) and upper trapezius muscle activity. DESIGN: A matched pair, case-control field study of female employees with and without SNP. BACKGROUND: It has proved difficult to distinguish subjects with SNP from those without by vocational electromyographic reco...

The amplitude of electromyographic (EMG) surface recordings on the upper trapezius muscle and its reproducibility during maximal voluntary contractions were examined. At different electrode positions 1.5-3.0 cm lateral to the midpoint between the seventh cervical vertebra (C7) and the acromion the mean maximal EMG amplitude estimates were within 90...

A case-control designed was used to investigate associations and interactions between muscle activity measured by surface electromyography (EMG) in the upper trapezius muscle and subjectively reported risk factors in workers with and without shoulder and neck pain. EMG data were collected both in the workplace (indicating vocational muscle activity...