From: Work. 2012 Jan 1;41(0):2535-8

The aim was to analyze the relationship between periods with uninterrupted neck muscle activity for ≥4 min and neck and shoulder pain. The trapezius muscle activity was recorded bilaterally on 40 young workers and students during a full shift. Neck and shoulder pain, mechanical work load and decision control were reported at the same time as the muscle activity recording and 6 months later. A dose-response relationship was found between uninterrupted muscle activity and neck and shoulder pain, with a ten-fold higher risk for the group with more than half, compared to less than a third, of the shift with uninterrupted muscle activity. Self-reported mechanical work load showed a small but protective effect related to pain. Gender and decision control did not emerge as important risk factors in this model. In conclusion, this study indicates that work or other exposures that contains long periods with uninterrupted neck muscle activity of 4 min duration or longer should be minimized to reduce risk of neck and shoulder pain.

Long periods with uninterrupted muscle activity related to neck and shoulder pain

From: J Orthop Sci. 2011 Nov 18. [Epub ahead of print]

The characteristics of neck and shoulder pain, called katakori in Japanese, have not been well documented to date. The aim of this study was to clarify the characteristics of neck and shoulder pain through a questionnaire survey of members of the nursing staff.

The study population consisted of 484 nursing staff members of Gunma University Hospital in Japan. The questionnaire involved information on age, body mass index (BMI), gender, psychological stress at work, musculoskeletal pain at other anatomic sites (elbow/wrist, lumbar and knee), smoking history, and hypertension. If subjects had neck and shoulder pain, they were asked about any coexisting symptoms, the utilization of health services, and the precise location of neck and shoulder pain.

The total study population included 393 persons after 91 persons were excluded for various reasons. The point prevalence of neck and shoulder pain was 68.1% (268 of 393). Age, BMI, smoking history, and hypertension showed no significant trend for the prevalence of neck and shoulder pain in the univariate analyses.

The occurrence of neck and shoulder pain was significantly higher in subjects with psychological stress, elbow/wrist pain, lumbar pain, and knee pain, respectively. A multivariate logistic regression analysis showed that gender, psychological stress, elbow/wrist pain, and lumbar pain were significantly associated with the occurrence of neck and shoulder pain. One hundred fifty-eight of those with neck and shoulder pain (58.9%) reported coexisting symptoms, and the most common was headache. Fifty-seven (21.2%) of the subjects with neck and shoulder pain had consulted medical or health practitioners, and bone setting was the most common service provider. The most common area of neck and shoulder pain was the superior part of the trapezius.

This study confirmed that neck and shoulder pain, katakori in Japanese, is a prevalent problem in a nursing staff, and several factors associated with neck and shoulder pain were identified.

From: BMC Musculoskelet Disord. 2011 Oct 12;12(1):230

Neck shoulder pain remains a major problem in work tasks with high exposure to awkward working positions, repetitive movements and movements with high precision demands. The trapezius muscle is considered particularly affected. The prevalence of chronic neck shoulder pain appears to be higher in women than in men. It causes high socioeconomic costs and significant loss of quality of life for the individual. Because of limited knowledge of the mechanisms involved in transition from acute to chronic pain, attempts to develop effective treatments have had limited success. The clinical manifestations of chronic pain conditions include both somatic (e.g., sensory disturbances, facilitated pain responses in association with movements, tense muscles with hyperalgesia for mechanical pressure/manual palpation) and psychological symptoms (e.g., sleeping problems, anxiety, and depressive symptoms).

Sensory hypersensitivity (central sensitization is sometimes used as a synonym while others use central sensitization as a term for specific mechanisms in the central nervous system (CNS)) is a common feature of several chronic neck shoulder pain conditions, particularly those with higher levels of pain intensity and disability. At the clinical examination, this can be manifested as increased sensitivity to manual palpation (i.e., pressure), but increased sensitivity to other sensory modalities, e.g., heat or cold, have also been described. Hypersensitivity to mechanical pressure or thermal pain is sometimes confined to the neck shoulder area but may also be present in remote pain-free areas, even though the clinical routine examination does not reveal clinical anatomical widespread pain and/or generalized hyperalgesia for different types of stimuli. Widespread deep tissue hyperalgesia has been found in patients with fibromyalgia, tension–type headache, whiplash associated disorders, idiopathic neck pain, epicondylalgia, low back pain, pelvic pain syndrome, and osteoarthritis.

It is generally acknowledged that the presence of widespread sensory hypersensitivity provides indication of augmented central pain processing mechanisms. Peripheral and central sensitization and alterations in descending inhibition mechanisms of nociception have been suggested as three of the underlying mechanisms of chronic musculoskeletal pain in general. It the context of muscle pain it has been suggested that neurobiological sensitization operating at somatic, cognitive and behavioral levels may increase the prevalence of e.g., sleeping problems, anxiety and depressive symptoms. Another explanation may be that such symptoms are secondary consequences of living with chronic pain.

Pain induction in an anatomical region distant from the clinical pain region is a common strategy to investigate signs of central sensitization and/or alterations in descending inhibition of neural activity and nociception at the spinal cord level. Assessments of pain sensitivity in deep tissue of non-painful regions of the body may be of importance for better understanding of the development of widespread hypersensitivity. Pressure pain thresholds using algometry have been used extensively to map mechanical sensitivity of mainly deep tissues such as muscles. Another modality (i.e., chemical) of the pain sensitivity of muscle can be investigated using the intramuscular hypertonic saline model with the opportunity to assess both aspects of sensitization and referred pain. The hypertonic saline model has been used extensively to characterize the sensory and motor effects involved in muscle pain, as the quality of the induced pain is comparable to acute clinical muscle pain and shows both localized and referred pain characteristics.

The anatomical spreading of experimentally induced muscle pain seems to alter in chronic musculoskeletal pain conditions; for example, patients with fibromyalgia experience stronger pain and larger primary and referred pain areas after hypertonic saline-evoked muscle pain compared with pain free controls. Such manifestations were present in the lower limb muscles, where these patients typically do not experience ongoing pain. Extended referred pain areas from the tibialis anterior muscle have also been found in patients with chronic whiplash associated disorders.

Both algometry and pain induction using the intramuscular saline model are psychophysical tests; i.e., an objective stimuli but a subjectively reported response by the tested subject. Noxious psychophysical tests require cooperation from the subject and attention, concentration, motivation and mood can reasonably affect the reports of the subjects tested. A bio-psycho-social model is preferred in clinical management of chronic pain since a blend of factors – neurobiological, psychological, coping styles, and contextual factors – contributes to the development and maintenance of chronic pain. Moreover, psychological factors, e.g., anxiety, depressive symptoms and fear, appear to play prominent roles in maladaptive responses to pain and in pain perpetuation. Hence, it is reasonable to assume that the psychological status can influence the reports of pain thresholds during psychophysical tests in chronic pain conditions.

Chronic whiplash associated disorders has been relatively extensively investigated concerning spreading of hyperalgesia as mentioned above. Studies of how widespread sensory hypersensitivity is in non-traumatic neck shoulder pain disorders, e.g., chronic neck shoulder pain, are, however, sparse and inconclusive and psychological aspects have not been extensively investigated in relation to pain responses to sensory tests in these patients.

The aim of this explorative study was to further investigate signs of sensory hypersensitivity, in terms of lowered pressure pain thresholds and more intense responses to painful hypertonic saline infusion, and the possible relationships to different psychological factors (sleeping problems, depression, anxiety, catastrophizing, and fear-avoidance beliefs) in women with chronic neck shoulder pain, and various extent of regional pain, compared with healthy controls.

Major results of the present study were:

The present study suggests that central sensitization mechanisms are involved in chronic nontraumatic neck shoulder pain without simultaneous clinical widespread pain since sensory hypersensitivity was found in areas distant to the region of clinical pain. A long history of chronic pain and high neck shoulder pain intensities were associated with low pressure pain thresholds both in the region of clinical pain and in distant pain free areas. Both pressure pain thresholds and chemically induced pain intercorrelated with intensity and area size of the clinical pain. Only the sensitivity to chemically induced pain was associated with the psychological status of the chronic non-traumatic neck shoulder pain but without simultaneous anatomically widespread clinical pain subjects.

From: J Bodyw Mov Ther. 2011 Jul;15(3):391-4. Epub 2011 May 28

Shoulder and neck problems frequently persist even after rest, physical therapy, medication, injections and even surgery. One of the great misunderstandings about musculoskeletal pain is that it is due to some injury or
structural pathology seen on an MRI or X-Ray. In spite of more and more structural imaging pain problems are becoming more persistent and chronic!

Over the past few years a new more functional approach has come into focus. Modern assessment of musculoskeletal pain has shifted from diagnosis of structural pathology to functional pathology. Dysfunction is nowrealized to be the“missing link” in the management of persistent musculoskeletal pain. In particular, the assessment and correction of faulty movement patterns which are the real source of biomechanical overload in the kinetic chain.

It is typical to have shoulder or neck pain without any relevant structural pathology on an MRI or X-Ray. Many
people have also been shown to have arthritis, or other structural problems such as a rotator cuff tear without
having any symptoms whatsoever. What then is it that predisposes one person to have pain or loss of physical capacity in one’s sport or activity?

A recent Stanford University study found that over 20% of their NCAA collegiate volleyball players WITHOUT shoulder problems had either tears or arthritic degeneration in their shoulders. The authors concluded that IF someone with pain has such structural abnormalities it should not be automatically assumed that they need surgery or need to live with the pain. Instead the real source of pain usually lies elsewhere.

The answer lies in what is called functional pathology of the motor system or dysfunctional movement. The most
important type of dysfunction is a faulty movement pattern. In the upper back, shoulder girdle or neck area the
key faulty movement pattern is an abnormal scapulohumeral rhythm. This causes the shoulder girdle to shrug up towards the ear(s) and results in increased neck/shoulder muscle tension, rounded shoulders, and forward head posture. These are the hallmarks of dysfunction which predispose to either pain or loss of athletic performance.

Once identified this faulty scapulo-humeral movement pattern or shrugged shoulder(s) should be the first goal of
treatment for musculoskeletal pain or training to build physical capacity for athletic development. A simple training method called the Y exercise which can be used to both identify and correct such a dysfunctional movement pattern.

The Y exercise involves testing and training with the arms in an overhead position making a letter Y shape. Some
clinicians or trainers will also use the T or W position.

Y exercises for correcting the most common faulty movement pattern of the shoulder/neck region

BMC Musculoskelet Disord. 2011 Sep 21;12(1):205. [Epub ahead of print]

Musculoskeletal disorders comprise a major burden on individuals and public health systems in North America and Europe. Neck and shoulder pains are among the most frequent health complaints among adults. Physical workplace factors such as repetitive work tasks, static contractions, and tiring postures are related to neck and shoulder pain. Studies have evaluated different types of physical exercise for treating neck and shoulder pain. While moderate to strong evidence for the effectiveness of strength training for relieving neck pain among office workers exists, evidence lacks among other occupational groups. Laboratory technicians – commonly exposed to high levels of strain in the neck and shoulders due to prolonged static loadings – show high prevalence of neck and shoulder pain. Based on previous research among office workers, investigating the effect of strength training on neck and shoulder pain among laboratory technicians is therefore relevant.

A British health survey reported that among the general population only 37% of men and 24% of women fulfilled public recommendations of physical activity. Thus, regular physical exercise is challenging for many people. In consequence, low adherence to exercise programs can negatively affect the outcome of randomized controlled trials, even in high quality studies. The major reason for not adhering to physical exercise is “lack of time”. Thus, workplace interventions with physical exercise during work hours and together with colleagues may reach people with low motivation for leisure physical exercise.

The present study has two major aims: Firstly, to evaluate the effect of strength training intervention at the workplace on non-specific neck and shoulder pain among industrial workers. Secondly, to describe the implementation process and adherence to the program.

The authors study showed that specific strength training reduced the overall level of neck pain among industrial workers. Among cases in the training group, the decrease in pain intensity of approximately 3 on a scale of 0-9 was considered clinically important. The industrial workers in the present study were highly exposed to known risk factors for development of musculoskeletal pain. Thus, a high percentage of daily activities were performed with static work postures and bent neck. In spite of the high physical occupational strain, high intensity strength training was effective in reducing neck pain in this job group.

The authors program, which effectively reduced neck and shoulder pain in laboratory technicians, involved dynamic muscle contractions with a high intensity (8-15 RM) and a high volume (6-12 sets per session) performed in a progressive manner with both linear and undulating periodization strategies throughout the training program. A variety of strength training protocols for decreasing neck pain have been described in the literature – i.e. low intensity training, high intensity concentric contractions, high intensity isometric contractions, low total training volume, and non-periodized training. The referred studies had in common that the effect of strength training was examined in selected symptomatic groups. In contrast, the finding of the present study is translational to the working population with repetitive work exposure and a high prevalence of neck and shoulder pain symptoms.

Chronic neck pain symptoms are known to display seasonal variation, worsening in the autumn and decreasing in the spring. Thus, a general decrease in neck pain symptoms could be expected as the study ran from January to June. Despite the well-known seasonal variation and thus a decrease of pain in the control group, we found a significantly better rehabilitative effect of strength training than control.

In contrast to the evidence on neck pain, only few high quality studies on training have been able to provide evidence for the effectiveness on shoulder symptoms. Among workers with shoulder pain at baseline, the odds ratio for being a non-case – i.e. having a pain intensity less than 3 at follow-up – were 3.9 in the training group compared with the control group. Thus, the present protocol provides a promising tool for treating pain in the shoulders among industrial workers. The preventative effect of training on development of pain symptoms – i.e. for non-cases at baseline – was negligible in the present study regardless of body part. A previous study showed that strength training performed for a one-year period had a small but statistically significant preventative effect on development of neck-shoulder symptoms among office workers. Thus, 20-week intervention duration may be insufficient to detect similar preventative effect.

A major strength of the present study is that regular adherence to training was achieved by 85% of the participants. Thus, the high adherence allowed us to investigate the actual effect of the intended intervention. Training facilities located within meters from the work station combined with a training program that could be conducted without changing clothes or subsequently needing a shower, allowed the participants to train whenever it matched into daily work activities. These factors combined with high availability of well educated training instructors may explain the high adherence. Overall, the high adherence shows that the workplace adjusted intervention model used in the present study can be successfully implemented at industrial workplaces.

Adverse events due to overload or incorrect strength training technique were minor and transient. Altogether, fifteen participants consulted the authors physiotherapist solely due to complaints from previous musculoskeletal injuries. All fifteen participants completed the 20-week training intervention, and showed – based on the baseline and follow-up questionnaire – a reduction in pain symptoms. However, four participants in the training group, who did not consult the authors physiotherapist, withdrew from the study and gave musculoskeletal pain as their reason. Thus, training may have provoked an adverse effect in the four participants mentioned, corresponding to approximately one percent of the participants of the training group.

The authors also compared baseline characteristics of those agreeing and declining, respectively, participation in the study. This comparison showed that employees with higher pain levels were more interested in participating than those with lower pain levels. Thus, pain per se is not a hindrance for participating in intensive strength training, rather on the contrary.

High-intensity strength training relying on principles of progressive overload can be implemented at industrial worksites with high adherence, and results in significant and clinically important reductions of neck and shoulder pain.

Related Neck Strengthening Exercises

From: Environ Health. 2011 Aug 4;10(1):70. [Epub ahead of print]

Complaints of arms, neck and shoulders is defined as the presence of musculoskeletal complaints of the said region not caused by acute trauma or by any systemic disease. complaints of arms, neck and shoulders is common among computer office workers worldwide and is a well recognized cause of occupational illness leading to frequent absenteeism from work, reduction in overall productivity, poor quality of life and escalating medical expenses. In the United States, complaints of arms, neck and shoulders is a leading cause of occupational illness with annual costs related to absenteeism from work and treatment being $45-54 billion. The recent increase in computer-related work as a consequence of rapid industrialization has considerably increased the prevalence of complaints of arms, neck and shoulders among computer office workers not only in western developed countries but also in developing countries such as Sudan and Sri Lanka.

The aetiology of complaints of arms, neck and shoulders among computer office workers is complex and poorly defined. Recently several studies have defined and identified potential risk factors for complaints of arms, neck and shoulders, such as physical exposure resulting from static body postures, repetitive tasks and workplace design. In addition, psychosocial factors such as high quantitative job demands, minimal autonomy and limited peer support have also been implicated. Thus, it is important that an aetiological model for complaints of arms, neck and shoulders, consider both physical and psychosocial factors. A significant majority of risk factor studies are from western developed countries and at present there are no studies from developing countries in the South-Asian region. Sri Lanka is a rapidly developing nation in South Asia having a population of about 19 million people.

Computer systems are being increasingly utilized to support the rapid industrial development, while ten percent of Sri Lankan households are known to be using personal computers. The estimated one-year prevalence of complaints of arms, neck and shoulders in Sri Lanka is 63.6%, which is comparable to the prevalence in developed countries. Hence, complaints of arms, neck and shoulders among computer office workers in Sri Lanka is likely to be causing a significant personal, industrial and economical impact. However, in order to design preventive strategies, identification of high risk sub-groups and an aetiological model needs to be defined with the recognition and quantification of risk factors and their interactions.

The present study is the first comprehensive report on the prevalence and risk factors of complaints of arms, neck and shoulders among computer office workers from a developing South-Asian county. The observed prevalence of complaints of arms, neck and shoulders among the Sri Lankan computer office workers was 56.9%, we also found that the reported complaints in the forearm and hand region was much higher than neck and shoulder complaints. The observed prevalence was similar to the prevalence reported from other developed countries. However, there is a scarcity of data from other similar developing countries in the region. In addition, we also demonstrate that complaints of arms, neck and shoulders in Sri Lanka has a potential to compromise workers quality-of-life and increase medical expenses as 22.7% had taken treatment from health care professionals for their ailments, while 9.3% reported complaints of arms, neck and shoulders-related absenteeism from work, and 15.4% reported complaints of arms, neck and shoulders causing disruption of their normal activities.

Upper musculoskeletal extremity complaints among computer office workers are known to be associated with both work-related psychosocial and physical factors. The present study shows that among the work related physical factors irregular body posture at work (twisted head and body, bent head and asymmetrical trunk) and bad work habits (sitting for long hours in one position, working with lifted shoulders and performing repetitive tasks) were significantly associated with complaints of arms, neck and shoulders. These factors were also determinants of the severity of complaints of arms, neck and shoulders among the study population, suggesting a dose-response relationship. However, the present study is not a prospective study and it is also possible that these factors could have exacerbated non-work related symptoms. Increasing hours of daily computer usage was also consistently associated with complaints in all regions and severity. In addition a majority of the workstations in the present study were ergonomically poorly designed and symptoms were more prevalent in those with poorly designed workstations.

In the scientific literature there is consensus that poor ergonomic conditions at workstations contributes to musculoskeletal symptoms. Studies have shown that holding the neck in a bent posture and working in the same posture for prolonged periods of time were both significantly associated with neck pain. The findings of the present study suggests that modification of incorrect postures at work and improvements in the ergonomic designs of workstations could be important not only as primary preventive strategies but also as a secondary preventive measure in those with symptoms. However the economic burden to employers, especially in developing countries like Sri Lanka hinders the complete improvements to workstation design. In such instances simple tools such as the OSHA VDT workstation checklist could be effectively utilized by employers in prioritizing issues.

Psychosocial factors are also important determinants of complaints of arms, neck and shoulders among computer office workers. In a systematic review it has been found that high job demand, low decision autonomy, time pressure, mental stress, job dissatisfaction, high workload, and lack of support from colleagues and superiors are risk factors for complaints of arms, neck and shoulders. The present study evaluated variables of the Karasek model in several domains (job demands, job control, social support and break time). Work overload (speeding to finish tasks on time, finding work tasks difficult and having too many tasks), poor social support (colleagues and superiors) and lack of autonomy (participation in decision making, deciding own task changes and determining time & speed job tasks) were associated with complaints of arms, neck and shoulders and also determined its’ severity. The similarity between odds ratios of the identified psychosocial factors and physical factors might suggest an equal contribution by both in the pathogenesis of complaints of arms, neck and shoulders. However strategies aimed at modification of psychosocial factors such as social support could be economically more efficient in an employers’ perspective.

The study participants also demonstrated relatively poor knowledge and awareness pertaining to ergonomics. In addition in those who were aware of ‘Ergonomics’, a majority lacked specific knowledge necessary for proper implementation. Poor ergonomic knowledge was also a significant predictor of complaints in the neck, forearm and hand regions. Implementation of a worksite ergonomics programs are known to be effective in reducing work-related complaints in the workforce. In addition, awareness programmes are also known to be cost-effective investments for employers’, as it reduces the occurrence of symptoms, improves productivity and reduces medical expense. The other potential barrier to successful primary and secondary prevention of this common problem in Sri Lanka is the relative lack of awareness related to the issue shown by health care professionals. The probable causes could be; the underestimation of the extent and common nature of the problem, lack of awareness on cause-effect relationship and hence non-attribution of symptoms to an occupational cause, ignorance of occupational history and the lack of appreciation of the effect of work place modification on symptoms.

The prevalence of work-related complaints of arms, neck and shoulders among computer office workers in Sri Lanka, a developing, South Asian country is high and comparable to prevalence in developed countries. Work-related physical factors, psychosocial factors and lack of awareness were all important associations of complaints of arms, neck and shoulders. Hence effective preventive strategies need to address all three areas. Further, studies on different interventional models are required to develop an effective preventive strategy for this relatively common and underestimated problem.

From: BMC Musculoskelet Disord. 2011 Jul 22;12(1):169.

A high prevalence of upper extremity pain exists among adults working in sedentary occupations. Neck and shoulder pain is a risk factor for long-term sickness absence among whitecollar workers, and every other office worker experience neck and shoulder pain on a weekly basis. Pain symptoms are believed to worsen in response to prolonged static muscle activity and/or repetitive job tasks, causing muscle metabolic disturbances.

There is a strong correlation between reported neck and shoulder pain and clinically verified muscle tenderness. Especially, tenderness of the upper trapezius muscle often co-exists with neck and shoulder pain. The upper trapezius muscle is – due to its bulky and superficial nature – well suited for clinical research, and displays clear physiological differences between symptomatic and non-symptomatic individuals regarding electromyographic activity, muscle strength, muscle fiber morphology, stem cell content, and intramuscular metabolites. In spite of the inordinate focus on the upper trapezius, other muscles of the neck and shoulder complex may be affected as well and should therefore not be overlooked when treating neck and shoulder pain.

A clinical protocol for diagnosing disorders of the neck, shoulder and arm – e.g. tension neck syndrome, frozen shoulder and lateral epicondylitis has been extended to include the diagnosis of trapezius myalgia – frequent neck pain with co-existing tenderness and tightness of the upper trapezius muscle. The overall prevalence of these disorders is low to modest and many people experience non-specific neck and shoulder pain, i.e. pain in absence of the aforementioned clinically diagnosed disorders.

This study shows a high prevalence of tenderness in several anatomical locations of the neck and shoulder complex among generally healthy adults with nonspecific neck and shoulder pain. Tenderness scores were highest in the levator scapulae and neck extensors in women, and highest in the levator scapulae in men.

The upper trapezius is a large superficial muscle extending from the occipital bone and cervical vertebraes to the acromion and lateral part of the clavicle. Much research on neck and shoulder pain has focused on the upper trapezius muscle. Although trapezius myalgia – chronic tenderness and tightness of the upper trapezius muscle – is the most common clinical diagnosis in adults with self-reported neck and shoulder pain, the results of this study show that severe tenderness more commonly occurs in the levator scapulae, neck extensors and infraspinatus. Although the levator scapulae, neck extensors and infraspinatus are smaller than the trapezius, research should focus also on these muscles and not only the upper trapezius.

The levator scapulae origins from the upper cervical vertebraes, extend along the back of the neck and inserts at the medial angle of scapulae. The neck extensor muscles – e.g. semispinalis and splenius – extend along the back of the neck. Together the levator scapulae and neck extensor muscles provide stability and prevent forward flexion and rotation of the neck during static work positions, e.g. at the computer. Although this study did not investigate the underlying mechanisms of tenderness, prolonged muscle fiber activation of the levator scapulae and neck extensors during long hours of computer work may lead to development of pain and tenderness.

This study shows that a high prevalence of infraspinatus tenderness also exists in adults with nonspecific neck and shoulder pain. The infraspinatus externally rotates the shoulder and provides stability and motion of the arm during many work tasks. During most types of computer work, e.g. when using the mouse or typing at the keyboard, the humerus is slightly externally rotated, which may put excessive stress on the infraspinatus and potentially lead to development of tenderness.

Although more sophisticated methods for research studies exists, e.g. digitalized pressure algometry, physical therapists primarily rely on their hands for manually diagnosing upper extremity disorders. As many of the investigated neck and shoulder muscles overlap anatomically – e.g. the trapezius muscles covers both the suprasinatus and levator scapulae – completely differentiating tenderness between muscles may not be possible. Nevertheless, the low kappa coefficients between the investigated anatomical neck and shoulder locations suggest that using the present method of manual palpation only minor overlap of tenderness exists. The weighted kappa coefficients show no systematic clustering of tenderness among the different anatomical locations of the neck and shoulder complex. As the method of manual palpation using a pre-learned pressure provides quick and reliable information on muscle tenderness, therapists may use the present screening tool to determine specific muscle tenderness in patients with neck and shoulder pain and thereby more efficiently target rehabilitation exercises.

This study is the first to report on the prevalence and anatomical location of palpable muscle tenderness among men with neck and shoulder pain. In spite of the limited male sample size, the authors showed clear gender differences for the prevalence of examiner-verified tenderness in spite of comparable subjective pain symptoms. While many women suffered from severe tenderness in several of the investigated muscles, the levator scapulae was the primary source of severe tenderness in men. Women generally have lower pressure pain thresholds than men, likely due to more potent neural inhibitory control mechanisms. Thus, using a standardized finger pressure of 2 kg may lead to stronger sensitivity of pain in women than men in spite of comparable questionnaire replies on neck and shoulder pain intensity. This suggests that application of these results to the general population should take gender into account.

The multiple regression analysis showed that tenderness of the levator scapula, infraspinatus and deltoid were significantly related to perceived neck and shoulder pain intensity. While this finding was not surprising regarding the infraspinatus and levator scapulae (i.e. both showed a high prevalence of tenderness), the significant influence of deltoid tenderness on perceived pain intensity was unexpected. Speculatively, tenderness of the deltoid muscle may reflect referred pain from undiagnosed progressing disease, e.g. shoulder joint osteoarthritis. Altogether, tenderness of the levator scapulae, infraspinatus and deltoid appears to be interesting areas for neck and shoulder research.

A high prevalence of tenderness in several anatomical locations of the neck and shoulder complex among adults with nonspecific neck and shoulder pain exists. These results indicate that research on neck and shoulder pain should focus on several muscles, including the levator scapulae, neck extensors and infraspinatus, and not only the upper trapezius.

From: Int J Occup Saf Ergon. 2011;17(2):195-205

Persisting neck pain is common in society. It has been reported that the prevalence of neck pain in office workers is much higher than in the general population. The costs to the worker, employer and society associated with work-related neck pain are known to be considerable and are escalating.

Neck and upper limb symptoms are frequently reported by computer workers. More than 50% of the computer workers report symptoms in neck, shoulders, arms, wrists or fingers. In the year 2002, 28% of the general Dutch working population suffered from pain or stiffness in the neck, shoulder, arms, hands or wrists in the previous 12 months. In Europe the prevalence for work-related neck/shoulder pain was 25% and 15% for work-related arm pain. The total yearly costs of neck and upper limb symptoms in the Netherlands due to decreased productivity, sick leave, chronic disability for work and medical costs were recently estimated at 2.1 billion euros.

The increase in computer and mouse use has been associated with an increased prevalence of disorders in the neck and upper extremities. Poor workstation design, continuous computer use for the entire workday and repetitive computer work, such as data entry, were associated with an increased risk of developing symptoms. It has also been shown that the musculoskeletal disorders associated with computer mouse use are increasing.

A positive relation has been found between various neck disorders and work related risk factors, such as static neck and arm postures, duration of sitting, as well as workplace design. Among other job characteristics, high quantitative job demands, having little influence on one’s work situation, and limited rest break opportunities have been found as predictors of neck pain.

Concerning video display unit work, the evidence of risk factors is based mainly on cross sectional studies. Increasing hours of computer use and incomplete work–rest cycle control, have been associated with musculoskeletal discomfort in the neck and shoulder area and upper extremities, especially when using input devices, such as a keyboard or a mouse. Computer use in sustained non-neutral postures, such as neck rotation and shoulder abduction, have been identified as risk factors for neck and shoulder symptoms. Postural stress caused by poor workstation ergonomics, such as inappropriate location of the screen, keyboard, or mouse, have been associated with musculoskeletal problems. By ergonomic interventions, such as supporting the forearm on the tabletop, a reduction of postural load, discomfort, or neck pain has been achieved. Work organizational factors, such as increasing work pressure or hurry and lack of job security or decision making opportunities, as well as problems in work atmosphere, may contribute to an increased occurrence of work related musculoskeletal complaints.

This study was to determine the prevalence and work-related risk factors of neck and upper extremity musculoskeletal disorders among video display terminal users. Methods. A comparative cross-sectional study was conducted; there were 60 video display terminal users and 35 controls. The participants filled in a structured questionnaire, had electrophysiological tests and an X-ray of the neck.

Among individual factors, female gender and older age have been found to be associated with a more frequent report of neck pain. Among health behavioural factors, smoking has been found as a risk factor, whereas the evidence on physical exercise has been inconsistent. A low frequency of exercise has been found preventive in some studies. Among sedentary workers a low physical activity has been a risk factor in some studies, whereas no effect has been found in some other studies. The role of psychosocial and psychological factors, such as stress, tension, depression, and job satisfaction has been frequently observed in the occurrence of various neck disorders.

The prevalence of neck and upper extremity musculoskeletal disorders was higher (28.3%) among video display terminals users compared to controls (14.3%) with no statistically significant difference. The prevalence of neck disorders with or without radiculopathy (18.3%) was the most common disorder followed by carpal tunnel syndrome (6.6%). The mean age of neck and upper extremity musculoskeletal disorder cases (51 ± 7.2 years) was statistically significantly higher than of the controls (42.8 ± 9). Physical exposure to prolonged static posture, awkward posture and repetitive movements increased risk of neck and upper extremity musculoskeletal disorders with a statistically significant difference for static posture only.

Video display terminal users experienced more job dissatisfaction, work-overload and limited social support from supervisors and colleagues. Video display terminal use did not increase the risk of neck and upper extremity musculoskeletal disorders. The risk increased with older age and static posture.

Prevention of neck disorders in office work with a high frequency of visual display unit tasks, attention should be given to the work environment in general and to the more specific aspects of visual display unit workstation layout. In addition, physical exercise may be preventive of neck disorders among sedentary employees.

Related Source:

Work related and individual predictors for incident neck pain among office employees working with video display units

From: Am J Epidemiol. 2011 Jun 1. [Epub ahead of print]

Chronic musculoskeletal complaints are among the major health problems in Western society, and the most frequent cause of long-term sickness leave in Norway. Chronic musculoskeletal complaints is associated with several negative determinants of health, such as smoking, overweight, and low socio-economic status. Increased risk of cancer and higher mortality have also been reported among individuals with chronic widespread musculoskeletal complaints, which further emphasizes that this group of patients may constitute an important public health problem.

Physical inactivity is, like chronic musculoskeletal complaints, associated with e.g. more sick leave, overweight, low socio-economic status, increased risk of cancer, and increased mortality.

It is well established that regular physical exercise has a primary preventive effect on several chronic diseases, such as cardiovascular diseases, hypertension, and
type 2 diabetes mellitus. For localized musculoskeletal disorders, prospective studies have provided evidence that regular physical exercise can prevent the development of symptoms in the neck/shoulder and low back. Moreover, longitudinal studies have shown that physical exercise is associated with less musculoskeletal pain and stiff or painful joints among aging women.

Chronic musculoskeletal pain constitutes a large socioeconomic challenge, and preventive measures with documented effects are warranted. The authors’ aim in this study was to prospectively investigate the association between physical exercise, body mass index, and risk of chronic pain in the low back and neck/shoulders.

The study comprised data on approximately 30,000 women and men in the Nord-Trøndelag Health Study (Norway) who reported no pain or physical impairment at baseline in 1984-1986. Occurrence of chronic musculoskeletal pain was assessed at follow-up in 1995-1997. A generalized linear model was used to calculate adjusted risk ratios.

For both females and males, hours of physical exercise per week were linearly and inversely associated with risk of chronic pain in the low back and neck/shoulders. Obese women and men had an approximately 20% increased risk of chronic pain in both the low back and the neck/shoulders. Exercising for 1 or more hours per week compensated, to some extent, for the adverse effect of high body mass index on risk of chronic pain.

The authors conclude that physical inactivity and high body mass index are associated with an increased risk of chronic pain in the low back and neck/shoulders in the general adult population.

Therefore, community-based measures aimed at reducing the incidence of chronic musculoskeletal complaints should emphasize the importance of regular physical exercise and maintenance of normal body weight.

From: Arch Phys Med Rehabil. 2011 Jun;92(6):849-58.

The study objective was to compare the effects of biofeedback with those of active exercise and passive treatment in treating work-related neck and shoulder pain in a randomized controlled trial with 3 intervention groups and a control group.

Participants were recruited from outpatient physiotherapy clinics and a local hospital. All participants reported consistent neck and shoulder pain related to computer use for more than 3 months in the past year and no severe trauma or serious pathology. A total of 72 potential participants were recruited initially, of whom a smaller group of individuals (n=60) completed the randomized controlled trial.

The 3 interventions were applied for 6 weeks. In the biofeedback group, participants were instructed to use a biofeedback machine on the bilateral upper trapezius muscles daily while performing computer work. Participants in the exercise group performed a standardized exercise program daily on their own. In the passive treatment group, interferential therapy and hot packs were applied to the participants’ necks and shoulders. The control group was given an education booklet on office ergonomics.

Pain (visual analog scale), neck disability index, and surface electromyography were assessed preintervention and postintervention. Pain and neck disability were reassessed after 6 months.
Postintervention, average pain and neck disability scores were reduced significantly more in the biofeedback group than in the other 3 groups, and this was maintained at 6 months. Cervical erector spinae muscle activity showed significant reductions postintervention in the biofeedback group, and there were consistent trends of reductions in the upper trapezius muscle activity.

Six weeks of biofeedback training produced more favorable outcomes in reducing pain and improving muscle activation of neck muscles in patients with work-related neck and shoulder pain.