Introduction: Musculoskeletal discomfort in the neck and shoulders is common among workers performing visually demanding near work, e.g., on a computer screen, and sustained low-level muscle activity during such work can lead to work-related pain. The relationships between visual demands and muscle activity and discomfort in the neck/shoulder region are at present unclear. Aim: The aims of this thesis were to determine whether neck/shoulder discomfort and trapezius muscle activity increases during visually demanding experimental near work, and to investigate whether eye-lens accommodation is a mediating mechanism behind increased trapezius muscle activity. Methods: The four papers included are based on two experiments with different visually demanding near work tasks (duration 5 and 7 min). Trial lenses of different diopters were used to manipulate the visual demands (i.e., induce more or less accommodation) and thereby create different viewing conditions. Monocular viewing, which does not require active convergence, was used to examine the isolated effect of accommodation. Eye-lens accommodation and trapezius muscle activity were measured continuously during the visual tasks, and in one experiment the participants rated their eye and neck/shoulder discomfort at baseline and after each visual task. Results: Neck/shoulder discomfort and trapezius muscle activity increased during the visually demanding near work and participants experiencing a greater increase in eye discomfort (compared with baseline) also developed more neck/shoulder discomfort with time. There were no significant differences in muscle activity among the viewing conditions, and no effect of isolated accommodation response within the monocular viewing conditions. Conclusion: These findings indicate that accommodation per se is unlikely to mediate trapezius muscle activity. Instead, the increase in trapezius muscle activity observed here may be due to a combination of high visual attention and enhanced requirement for eye-neck (head) stabilisation. Since these results suggest that neck/shoulder discomfort may aggravate with time when the visual demands are high, it is important to provide good visual conditions in connection with visually demanding occupations. / Introduktion: Muskelrelaterade besvär i nack- och skulderområdet är vanligt förekommande, framförallt hos individer som utför synkrävande datorarbete. En orsak till sådana besvär anses vara långvarig lågintensiv aktivitet i dessa muskler. Det är i dagsläget oklart om de belastningar som synsystemet utsätts för vid synkrävande arbete bidrar till ökad muskelaktivitet i nack/skulderregionen. Syfte: Syftet var att undersöka om experimentellt synkrävande närarbete påverkar muskelaktivitet och besvär i nack/skulderregionen, och att undersöka om aktivitet i trapezius muskeln (kappmuskeln) påverkas av ögats ackommodation, d.v.s. när linsens brytkraft förändras för att se skarpt på nära håll. Metod: De fyra delstudierna baseras på två laborativa experiment där försökspersoner (66 respektive 26 stycken) genomförde olika synkrävande uppgifter (fem och sju minuter långa). För att göra synuppgifterna mer eller mindre ansträngande för synsystemet användes linser med olika grad av brytkraft (dioptrier). Dessutom, eftersom monokulärt seende inte kräver aktiv konvergens, genomfördes tre av de fyra synuppgifterna i ena experimentet med ett öga för att undersöka den enskilda effekten av ackommodation. En autorefraktor mätte ögats ackommodation under synuppgifterna och aktiviteten i trapeziusmuskeln registreades kontinuerligt med elektromyografi (EMG). I samband med det ena experimentet skattade deltagarna sina upplevda ögon- och nack/skulderbesvär, både före experimentet (baslinje) och efter varje synuppgift. Resultat: Det synkrävande arbetet ökade både de självskattade nack/skulderbesvären och muskelaktiviteten i trapezius. De personer som upplevde en högre ökning av ögonbesvär (i förhållande till baslinjen), rapporterade också mer nack/skulderbesvär över tid. Det var varken någon signifikant skillnad i grad av muskelaktivitet mellan synuppgifterna, eller något signifikant samband mellan monokulär ackommodation och muskelaktivitet. Slutsats: Resultaten indikerar att ögats ackommodation, i sig, inte påverkar muskelaktiviteten i trapezius. Ökad muskelaktivitet i nack/skulderregionen i anslutning till synkrävande arbete kan istället bero på en kombination av höga krav på visuell uppmärksamhet och ett ökat behov av att stabilisera ögonen (huvudet) i förhållande till objektet i fokus (t.ex. texten på en bildskärm). Eftersom resultaten tyder på att synkrävande närarbete leder till ökade besvär i nack/skuldraregionen över tid, är det viktigt att utforma arbetsplatser och synkrävande arbetsuppgifter (t.ex. vid datorn) på ett sätt som främjar visuell hälsa.

Thesis (MScPhysio)--Stellenbosch University, 2015 / ENGLISH ABSTRACT: Background: The use of computers at school, university, work and for social media is growing and whilst neck pain is common in the general population, computer users have an even higher prevalence. Incorrect workstation ergonomics have been identified as a risk factor for the development of neck pain in computer workers. Aims: To assess the effect of adjusting chair and monitor height of a female office worker’s computer workstation on work related neck and upper back pain intensity, comfort of her sitting posture and disability. Methods: An N=1 study was conducted using the A-B-C design consisting of a computer workstation adjustment involving chair and monitor height of a female office worker. The effect of the intervention was evaluated using the Visual Analogue Scale (VAS) to measure neck and upper back pain intensity and comfort of sitting position, and the Neck Disability Index to measure disability. The effect of the intervention was assessed over the three phases, consisting of four weeks each. During these phases, the participant could continue with her usual computer work. The results were compiled and tabulated. Results: A reduction in neck and upper back pain intensity as well as an increase in sitting comfort position were found. However these improvements were not statistically or clinically significant. The effect size for pain intensity was 0.76 and for sitting comfort 0.21. The participant reported no disability as measured by the Neck Disability Index, at the start and at the end at the end of the study. Conclusion: The vertical adjustment of this female office worker’s chair and monitor height according to her anthropometrics improved neck and upper back pain intensity and comfort of sitting position. This ergonomic workstation intervention could form part of a practical management option for computer users with neck and upper back pain. Further research is recommended to establish whether these findings are generalizable to the wider community of computer users. / AFRIKAANSE OPSOMMING: Probleemstelling: Die gebruik van rekenaars by skole, universiteite, werksplekke en vir sosiale doeleindes neem toe. Nek pyn kom dikwels in die algemene bevolking voor, maar dit is meer prevalent in rekenaargebruikers. ‘n Werkstasie wat nie ergonomies korrek opgestel is nie, is geidentifiseer as ‘n risikofaktor vir die ontwikkeling van nekpyn in rekenaar werkers. Doelwitte: Om te bepaal of aanpassings in die stoel- en beeldskerm hoogte van ‘n vroulike kantoor werker se rekenaar werkstasie, ‘n effek het op werksverwante nek en boonste rug pyn, sitgemak en funksionele vermoë. Methode: Die N=1 studie met ‘n A-B-C ontwerp is onderneem en het bestaan uit n rekenaar werkstasie aanpassing waarby die hoogte van die stoel en beeldskerm van ‘n vroulike relenaargebruiker aangepas is. Die effek van die intervensie is ge-evalueer deur middle van die visueel analoogskaal (VAS) om pyn en sitgemak te bepaal; en die Nek Ongeskiktheids Indeks (NOI) om gestremtheid te bepaal. Die effek van die intervensie is oor drie fases, wat elk bestaan het uit vier weke, evalueer. Gedurende die fases, kon die deelnemer met haar gewone rekenaarwerk voortgaan. Die resultate is saamgestel en getabuleer. Resultate: Daar was ‘n vemindering in die intensiteit van nekpyn, boonste rug pyn en die sitgemak van die individu het ook verbeter. Hierdie verbeteringe was egter nie statisties of klinies betekenisvol nie. Die effek grootte vir pyn intensiteit was 0.76 en vir sitgemak was 0.21. Die deelnemer het geen gestremdheid gerapporteer, soos gemeet met die NOI met aanvangs van die studie of teen die einde van die studie nie. Gevolgtrekking: Die vertikale hoogte-aanpassing van die stoel en beeldskerm van hierdie vroulike rekenaar werker volgens haar antropometrie het bygedra tot ‘n verbetering in nek en boonste rug pyn, asook sitgemak. Hierdie ergonomiese werkstasie intervensie kan deel vorm van die praktiese hantering van nek en boonste rug pyn in rekenaargebruikers. Verdere navorsing wod aanbeveel om te bepaal of hierdie bevindinge veralgemeenbaar is na die wyer gemeenskap van rekenaarverbruikers.

Submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic, Durban University of Technology, Durban, South Africa, 2016. / Background: Musculoskeletal disorders (MSDs) are a significant and common occupational health concern, consequently impacting work attendance and performance. High prevalence rates of MSDs have been reported amongst school teachers. Studies have linked these higher prevalence rates to typical daily teaching activities including prolonged standing, awkward postures, heavy lifting, bending and repetitive movements. Objectives: To determine the prevalence of neck, shoulder and low back pain among primary school teachers in the Central Durban area; to identify any risk factors associated with neck, shoulder and low back pain; and to establish the relationship, if any, between the prevalence and risk factors of neck, shoulder and low back pain among primary school teachers. Methods: This was a quantitative, descriptive and cross-sectional study, conducted in 12 selected public primary schools within the Central Durban area. Volunteers who met the inclusion criteria (n = 97) were invited to complete self-administered questionnaires. Results: Of the 97 completed questionnaires 83.1 percent (%) reported neck and shoulder pain and 71.0% low back pain. Neck and shoulder pain were significantly associated with a forward-bent head posture (p = 0.001), ethnicity (p = 0.001), and history of a severe trauma/injury (p = 0.006). Similarly, significant associations were noted with regards to medical conditions (p = 0.006), a backward-bent head posture (p = 0.016), lifting of heavy loads (p = 0.045) and treatment for severe injury (p = 0.047). Associations were also noted between low back pain and prolonged standing (p = 0.000), ethnicity (p = 0.008), transportation methods (p = 0.023), medical conditions (p = 0.031) and a history of a severe trauma/injury (p = 0.049). Conclusion: This is a first South African study, to our knowledge that highlights increased prevalence rates for both neck and shoulder pain and low back pain amongst teachers, with a variety of associated risk factors. This draws attention to the urgent need for intervention programs to be implemented to prevent/reduce the development of musculoskeletal pain amongst teachers. / M

Background: Pain associated with the spine (PAWS) refers to pain in the neck, thorax, lower back or sacrum. It impacts on patients' Quality of Life (QoL), including working ability, daily functioning, sleep and psychological well-being. A number of clinical trials have demonstrated that acupuncture was beneficial for patients with PAWS. However the overall effect of acupuncture on these patients' QoL is unknown. Aims: The current study aimed to conduct a systematic review (SR) of clinical trials to determine the effect of acupuncture on QoL and pain for patients with PAWS. In addition, a narrative review (NR) was conducted to compare patients' perceived changes (PCC) with the standard QoL instruments used in acupuncture clinical trials for pain. Methods: For the SR, PubMed, Embase (via ScienceDirect), CINAHL (Via EBSCO) and Cochrane Central Register of Controlled Trials were searched. Randomised controlled trials (RCTs) of acupuncture for PAWS condition(s) that include both QoL and pain assessments with a Jadad score of three or greater were included. For the NR, PubMed was searched to identify studies reporting PPC after acupuncture and/or traditional Chinese medicine. Extracted data were grouped and compared with domains of the QoL instruments. Results: In total, 21 RCTs were included and 17 of them had sufficient data for analysis. QoL was measured using 15 different instruments. Randomisation procedures and dropouts were adequately reported in all 17 studies. Four studies compared acupuncture with wait-list or usual-care. Two demonstrated that acupuncture had a superior effect on improving physical and mental components of QoL measured by Short Form-36 health survey questionnaire and pain at the three month follow-up. Studies comparing acupuncture with sham/placebo acupuncture or placebo-TENS found either no difference between the treatments or conflicting results. When acupuncture was compared with active interventions, there was no difference except that at the intermediate-term follow-up massage was better for disability and pain and physiotherapy was better for Northwick Park Neck Pain Questionnaire. Acupuncture was also better than TENS for pain. The combined therapy of acupuncture and an active intervention showed a superior result than the latter alone in the short-term. Six studies were identified for the NR. Patients reported 11 categories of changes after acupuncture, such as reduced reliance on other therapies, enhanced spirituality, prevention of disease. However, these clinical outcomes were not included in any of the QoL instruments used in the included RCTs. Conclusion: There is moderate to strong evidence that acupuncture is more effective than wait-list or usual-care at the short-term follow-up in improving QoL of patients with PAWS. When acupuncture is combined with another therapy, the combined therapy seems to produce a better outcome. Acupuncture is not better than sham/placebo acupuncture or placebo-TENS. Surprisingly, the commonly used QoL instruments do not measure all the changes perceived by patients as a result of acupuncture and/or traditional Chinese medicine. There is a pressing need to design QoL assessments that are suitable for acupuncture research. Further studies should have larger sample sizes and additional validated outcome assessments are required to detect effects of acupuncture.

ABSTRACT Whiplash associated disorders (WAD) is one of the most debated musculoskeletal conditions. Sensory disturbances including hypersensitive responses to mechanical, thermal and electrical stimulation have been consistently shown to be a feature of both the acute and chronic stages of the whiplash condition. More importantly, such dysfunctions have also been found to be associated with higher risk of poor functional recovery. It is apparent that better understanding of the sensory disturbances in WAD is needed in order to elucidate mechanisms underlying the pain and disability of this recalcitrant condition and to facilitate the development of more effective management strategies. Comprehensive Quantitative Sensory Testing (QST) combining sensory detection and pain threshold measures is proving to be a valuable tool to advance the classification and illuminating the underlying mechanisms of an array of musculoskeletal pain disorders but such protocol has never been undertaken in a WAD cohort. In order to fill this gap in knowledge, the series of studies in the thesis aimed to utilize comprehensive QST to investigate the presence of somatosensory dysfunction in chronic WAD and to compare the somatosensory profile of WAD to cervical radiculopathy and idiopathic (non-traumatic) neck pain. Once a better understanding of the potential underlying mechanisms in chronic WAD was established, the research then focused on documenting the presence of such somatosensory disturbances soon after whiplash injury and its temporal development over a 6 months period. The results have provided a number of significant insights into some of the potential underlying mechanisms of the somatosensory dysfunction in WAD as well as other neck pain conditions of different aetiology. It is clear that generalised sensory hypoaesthesia coexisted with sensory hypersensitivity in chronic WAD and a combination of pain and detection measures best discriminated patients with WAD and controls. Similar sensory presentation was also found in patients with cervical radiculopathy but not in idiopathic neck pain patients. This finding indicates that different mechanisms underlie various musculoskeletal conditions with disordered central processes contributing to a greater degree in some conditions. Patients with whiplash and those with cervical radiculopthy may share similar underlying pain mechanisms involving the central nervous system and the discrepant findings in the idiopathic neck pain group may be due to the magnitude of nociceptive input required to induce/maintain altered central adaptive changes. Another important observation from the studies was that sensory hypoaesthesia was present in the majority of patients with whiplash injury in the acute stage. However, it persisted only in individuals who initially reported higher levels of pain and disability levels and sign of hypersensitivity. It was this group of individuals who predominantly developed persistent symptoms at six months post injury. The longitudinal findings indicate that such sensory impairments can be identified very early on and treatment interventions directed at these sensory disturbances (both sensory hypersensitivity and hypoaesthesia) should aim to reduce the nociceptive input and this may improve recovery post whiplash injury. The findings in this thesis demonstrated the clear association between sensory hypersensitivity and other sensory disturbances and their potential influence on recovery. Furthermore, the heterogeneity of the whiplash condition highlighted the importance of the early identification of “low-risk and “high-risk” patients in order to assist the clinicians to make clinical decisions on the best management approach. It cannot be overemphasised that the early assessment of whiplash injured patients should aim to identify features associated with poor recovery and a better classification system will be an important step. Implications for assessment and management of whiplash are vital in the acute stage of injury and may well go some way toward preventing the transition to chronicity, particularly in those with a more complex clinical presentation involving somatosensory disturbances. Further research directions have also been identified in order to improvement management of this complex clinical condition.

Neck-shoulder pain is common in the general population and causes individual suffering as well as large costs for the society. Despite substantial efforts, there is still a shortage of methods for objective diagnosis and effective rehabilitation of such disorders. Thus, there is a great need to develop and evaluate new methods for these purposes. From clinical observations and recent research it has become evident that sensorimotor control can be impaired in people with neck-shoulder pain and may play a role in the pathogenesis of these disorders. In this thesis, precision of goal-directed arm movements, a previously unstudied class of movements in neck-shoulder pain, was studied. The main aim of the thesis was to investigate if people with chronic neck-shoulder pain have a reduced acuity of goal-directed movements of the upper extremity. A second aim was to study associations between reduced movement acuity and symptoms and self-rated characteristics. Upper limb repositioning acuity was assessed in blindfolded subjects performing tests of active, ipsilateral position-matching of two target positions (long and short) in movements constrained to horizontal-adduction of the shoulder. Reduced repositioning acuity, suggesting impaired shoulder proprioception, was found for both subjects with whiplash associated disorders (WAD) and non-specific neck-shoulder pain (NS). The degree of reduced acuity was shown to correlate with self-ratings of various health concepts, functioning and pain. A conspicuous finding was that there was lack of correlation between short and long target errors, along with the fact that associations between repositioning acuity and symptoms and self-rated characteristics was primarily found for the short target position. To further investigate the possible mechanisms underlying the disassociation between long and short target movement control, the association pattern between the outcome of several variants of ipsilateral position matching and velocity-discrimination tests, were studied. It was found that the perception of limb position in position-matching of short target locations appears to be predominantly based on movement velocity, whereas perception of limb position in movements to longer target locations may rely on a location-based perception mechanism. To extend the research on reduced upper extremity proprioception in neck-shoulder pain to a more natural movement situation, acuity of goal-directed pointing including full vision and 3D multi-joint movements was investigated in WAD, NS and healthy controls subjects. The results revealed a reduced acuity for both neck-pain groups. Moreover, distinct associations between end-point acuity and neck movement problems, limitations of some physical functions and, in WAD; some aspects of pain, were revealed. The findings demonstrate that the precision of upper limb movements can be reduced in chronic neck-shoulder pain. Substantial associations with symptoms and self-rated functioning suggest a clinical relevance of acuity measures of goal-directed arm movements. The findings indicate that tests of sensorimotor control can provide objective measures that may be useful in biopsychosocial profiling and characterization of subgroups of patients with chronic neck-shoulder pain, and that training target control of goal-directed movements should be considered in rehabilitation programs of people with these disorders.

The overall aim of this thesis was to evaluate effects of a multi-component pain and stress self-management group intervention (PASS) and to explore plausible predictors associated with short-term and long-term treatment effects among patients with persistent tension-type neck pain in primary health care (PHC). Study I was a pilot study in order to explore feasibility of the study design and methods. It included 37 participants randomly assigned to the intervention (n=18) or treatment-as-usual (n=19). Study II-III was a pragmatic randomized controlled trial that compared effects of the PASS and individually administered physiotherapy (IAPT) on patients with persistent tension-type neck pain in PHC. Study II evaluated short-term effects over a 20-week follow-up. Study III evaluated long-term effects on maintenance over a follow-up period of 2 years. Studies included 156 participants randomly assigned to PASS (n=77) or IAPT (n=79). Study IV explored predictive factors for favorable outcome in disability regarding participants assigned to PASS. The results showed that PASS had better effects than IAPT regarding coping with pain, in terms of patients’ ability to control pain, self-efficacy regarding activities interfered with by pain, disability and catastrophizing, over the 20-week follow-up, and treatment effects were largely maintained over a 2-year follow-up. Post-treatment scores in disability, self-efficacy and pain intensity were associated with long-term outcome in pain-related disability 2 years post-treatment following PASS. Pre-treatment characteristics explained only a minor proportion of variance in disability, and were assumed weakly associated with treatment success and long-term outcome. Key components for enhancement of long-term efficacy in pain self-management coping efforts were adequately targeted by PASS. It is suggested important to strengthen self-efficacy beliefs in regard to pain coping, to reduce disability and enhance pain self-management in the treatment of persistent neck pain, and to induce long-term maintenance of treatment gains on disability following a pain self-management intervention.

Människor med rygg- och nackvärk utgör en stor patientgrupp inom primärvården. Många blir inte hjälpta av de behandlingsmetoder som erbjuds. Samtidigt efterfrågas Komplementär och Alternativ Medicinska (KAM) behandlingar allt mer från allmänheten. Behovet att öka hälso- och sjukvårdens kunskap om KAM som behanlingsalternativ sågs. Studiens syfte var att beskriva människors erfarenheter i samband med rygg- och nackvärk och reflexologisk behandling. Metoden var kvalitativ ansats med semistrukturerade intervjuer som analyserades utifrån kvalitativ innehållsanalys. Urvalet omfattade sju klienter som sökt reflexologisk behandling pga rygg- och/eller nackvärk och identifierades genom tre olika reflexologer i Skåne län. I resultatet identifierades kategorin Vardagen med underkategorierna Smärta och värk, Försök till anpassning samt Söka vård och behandling. I Kategorin fysiska och psykiska sensationer sågs underkategorierna Personligt bemötande, Zonsmärta, Cirkulationsökning samt Avslappning. I Kategorin Förändring av vardagen ingick Symtomlindring, Hjälp till självhjälp samt Arbete och idrott. Slutsatsen dras att reflexologisk behandling kan erbjuda bra smärtlindring för människor med rygg- och nackvärk samt erbjuder en chans till avslappning, bättre sömn, vara aktiv i arbetslivet och få ny energi. Mer forksning inom reflexologisk behandling behövs. / People with back- and neck pain are common in primary care. Lot of patients don´t get the help needed. Meanwhile the public´s interest in Complementary Alternative Medicine (CAM) is growing. Need was identified to in the Healthcare system increase the knowledge about CAM´s options of treatment. The aim of this study was describing peoples experiences associated with back-and neck pain and reflexological treatment. The method was qualitative approach with semistructured interviews that analysed with contentanalysis. Sample included seven clients soughted reflexological treatment for back-and/or neck pain, wich identified through three flexologists in South Sweden. In The result the category Everyday life was identified with subcategories Pain and ache, Attempts to adapt and also Seek care and treatment. In the category Physically and mentally sensations subcategories Personal treatment, Zone pain, Increasing of circulation and also relaxation was identified. In the category Change in everyday life subcategories Symptom relief, Help to self-help and also work and sports were observed. Conclusion is that Reflexological treatment relief pain for people with back- and neck pain, it also provides chance for relaxation, better sleep, be able to work and to get new energy. More research about reflexological treatment is needed.

Chronic neck pain is a widespread problem that causes individual suffering as well as large costs for the society. The knowledge about the pathophysiology is poor and therefore specific diagnosis and causal treatment are rare. Important knowledge for characterization of the disorders has been gained from research on sensorimotor functions in people with neck pain. Moreover, rehabilitation regimes including sensorimotor exercises indicate promising results. The main objectives of this thesis were to extend the knowledge on sensorimotor dysfunctions in chronic neck pain, and to develop a new exercise method for improving sensorimotor functions of the neck. The studies focused on aspects of postural control and movements of the arm and neck. These are vital functions for many activities of daily living. People with chronic (>3 months) neck pain were compared to healthy controls (CON). Neck pain related to trauma was referred to as whiplash associated disorders (WAD), while neck pain without association to trauma was referred to as non-specific (NS). Arm-functioning was assessed in a pointing task. WAD and NS had reduced pointing precision compared to CON. The reduced precision was associated with self-rated difficulties performing neck movements, physical functioning, and in WAD, also pain and balance disturbances. Postural control was assessed in quiet standing on a force platform without vision. The center of pressure signal was decomposed into it’s slow and fast components. WAD and NS were compared to CON. The results revealed an effect of age on the magnitude of the fast sway component, but no effect of group. The magnitude of the slow component was elevated in both WAD and NS. This increase was associated with self-rated balance disturbance, arm-functioning, difficulties to run and sensory alterations in WAD, while in NS, the increase in the slow sway component was associated with concurrent low back pain. Neck movements were assessed in a cervical axial rotation test with maximal speed. In total 8 variables representing basic kinematics, including variables reflecting movement smoothness and conjunct motions were calculated. NS were compared to CON. Linear discriminant modelling indicated Peak Speed and conjunct motions as significant classification variables that together had a sensitivity of 76.3% and specificity of 77.6%. Retest reliability was good for Peak Speed but poor for the measure of conjunct motions. Peak Speed was slower in NS compared to CON, and even slower in a sub-group of NS with concurrent low back pain. Reduced Peak Speed was associated with self-rated difficulties performing neck movements, car driving, running, sleeping disturbances and pain. The clinical applicability of a novel method for neck coordination exercise was assessed in a pilot study on persons with NS. The results supported the applicability and indicated positive effects of the exercise: reduced postural sway in quiet standing and increased smoothness in cervical rotations. Indications on improvement in self-rated disability and fear of movement were seen at six months follow up. In conclusion, sensorimotor functions can be altered in chronic neck pain, particularly in neck disorders with concurrent low back pain and WAD. The discriminative ability and clinical validity displayed in pointing precision, postural sway and cervical axial rotation speed imply that such tests can be valuable tools in the assessment of chronic neck pain patients, and for selecting and evaluating treatment interventions. Indications of improvements seen in the pilot-study support a future RCT.

Introduction: Neck pain is a common problem in society and is more prevalent among women. The consequences of neck pain for the individual often include activity and participation limitations, thus affecting many dimensions of life. There is still a lack of understanding of the underlying mechanisms of the disorder and likewise of efficient rehabilitation for people with neck pain. However, coordination exercises have shown promising short-term effects. To carry this line of research forward, there is a need to improve methods for objective characterization of impairments and to investigate novel methods of rehabilitation. Aims: To characterize impairments of active cervical range of motion of the upper and lower cervical levels in women with chronic neck pain with a novel method (Study I and II) and identify the influence of head posture and movement strategies (Study II). Further, to investigate the effects of a novel method for neck coordination exercise on sensorimotor function and neck pain (study III) and the consistencies of motor variability metrics in a goal directed arm movement task to aid the design of future clinical research (Study IV). Methods: All studies were laboratory based with kinematic assessments of neck movements (Study I-III), balance (Study III) and goal directed arm movements (Study III, IV). The studies had designs that were: cross-sectional (I and II), randomized controlled trial (III) or test-retest reliability study (IV). Participants in Study I (n=135) and II (n=160) were women with chronic non-specific neck pain and healthy controls. In Study III, women with chronic non-specific neck pain (n=108) were randomized into three different individually supervised 11 week interventions. Study IV included healthy women (n=14). Results: It was found that cervical range of motion impairments in women with non-specific neck pain were direction- and level-specific; impairments were greater in extension in the upper and flexion in the lower levels of the cervical spine. The magnitude of impairments in range of motion was associated to self-ratings of functioning and health. Possible group differences in natural head posture were rejected as a cause for the direction specific effects. Neither could the effects be explained by a strategy to minimize torque in the cervical spine during movement execution. The neck coordination training was not superior to strength training (best-available) and massage treatment (sham) in improving sensorimotor functions or pain according to short-term and 6 months follow ups. The results from the study of the goal directed movement task showed that between and within-subject sizes of most motor variability metrics were too large to make the test suitable for application in clinical research. Conclusions: Women with chronic non-specific neck pain have direction- and level-specific impairments in cervical sagittal range of motion. The underlying causes of these specific impairments remains unresolved, but the direction specific impairments are not related to natural head posture. The clinical validity of the method of characterization of cervical range of motion was supported and it can be useful in future clinical research. The novel method of neck coordination exercise showed no advantages on sensorimotor functions or pain compared with best-available treatment in women with chronic non-specific neck pain. / Långvarig smärta i nacken är vanligt förekommande och orsakar både personligt lidande och stora kostnader för samhället. Långvariga nackbesvär är vanligare hos kvinnor än hos män. Det saknas kunskap om effektiva rehabiliteringsmetoder, men forskning har indikerat att träning som förbättrar nackens koordination kan vara effektivt. För att uppnå bättre rehabiliteringsresultat är det viktigt att utveckla metoder för att objektivt mäta funktionsnedsättningar och att utveckla samt utvärdera nya rehabiliteringsmetoder. Syftet med avhandlingen kan sammanfattas i tre delar: Att detaljerat mäta nedsättningar i nackens rörelseomfång hos kvinnor med långvarig nacksmärta; att utvärdera effekten av en ny metod för nackkoordinationsträning på rörelsefunktion och smärta hos kvinnor med långvarig nacksmärta; samt att utvärdera ett nytt test för att mäta precision och koordination vid målriktade armrörelser och ämnat för framtida klinisk forskning. Resultaten visade att kvinnor med långvarig nacksmärta hade specifika nedsättningar i nacken rörelseomfång; i övre nackregionen var bakåtböjning mer begränsad medan i nedre nackregionen var framåtböjning mer begränsad. Vi kunde utesluta att resultaten berodde på skillnader i huvudets normala hållning. Graden av rörelsebegränsning i nacken uppvisade samband med personernas självskattade funktion, symtom och hälsa. Nackkoordinationsträningen var inte var bättre än styrketräning eller massage för att förbättra rörelsefunktion eller för att minska smärta. Det nya testet för armrörelser var inte lämpat för kliniska studier av rörelseprecision. Slutsatserna från avhandlingsarbetet är att kvinnor med långvarig nacksmärta har begränsningar i nackens rörelseomfång vid framåt- och bakåtböjning av huvudet som är specifika vad gäller nivå i halsryggen och riktning. Att graden av rörelsebegränsning uppvisade samband med självskattad funktion, symtom och hälsa styrker testets kliniska validitet. Ytterligare forskning behövs för att förstå orsakerna bakom de specifika nedsättningarna. Nackkoordinationsträningen som utvärderades kan inte rekommenderas för kvinnor med långvarig nacksmärta eftersom korttidsuppföljning och 6-månadersuppföljning visade att träningsformen inte var bättre än styrketräning eller massage, vare sig när det gällde att förbättra sensomotorisk funktion eller att minska smärta.