Repeatability and validity of an upper limb and neck discomfort questionnaire: the utility of the standardized Nordic questionnaire

The repeatability and validity of a questionnaire for upper limb and neck complaints were assessed in a population of 105 hospital outpatients with a range of upper limb and neck disorders (including cervical spondylosis, adhesive capsulitis, lateral epicondylitis, carpal tunnel syndrome and Raynaud's phenomenon). Subjects were asked to complete a modified Nordic-style upper limb and neck discomfort questionnaire on two occasions closely spaced in time. The repeatability of their responses was assessed by calculating a kappa coefficient (kappa), and the sensitivity and specificity of component items in the questionnaire were determined for specific diagnostic categories of upper limb and neck disorder. Symptom reports for pain in the upper limb and neck, pain interfering with physical activities, neurological symptoms and blanching were all found to be highly repeatable (kappa = 0.63-0.90). A number of regional pain reports proved to be very sensitive in relation to specific upper limb disorders, but, with the exception of reported finger blanching in patients with Raynaud's phenomenon, none proved to have a good specificity (range = 0.33-0.38). We conclude that a modified Nordic-style questionnaire is repeatable and sensitive, and is likely to have a high utility in screening and surveillance. However a complementary examination schedule of adequate specificity and repeatability is essential to establish a clinical diagnosis.     

Risk factors for specific upper limb disorders as compared with non-specific upper limb pain: assessing the utility of a structured examination schedule

BACKGROUND: Few community-based epidemiological investigations of upper limb disorders (ULDs) have classified cases by validated procedures involving a structured clinical examination. AIM: To compare risk factor profiles for different diagnostic categories of ULD using one such examination scheme. METHODS: A questionnaire about upper limb pain and demographic, occupational and psychosocial risk factors was mailed to 10,264 adults from two English general practices, followed by standardized physical examination in those with arm or neck pain. Logistic regression was used to compare those with specific ULDs and non-specific arm pain with those who had no neck or arm symptoms. RESULTS: There was a 59% response rate. A total of 1,197 subjects with arm or neck pain underwent standardized physical examination and were classified as having one or more of 11 specific ULDs or non-specific regional pain. Among these, 250 subjects with specific ULDs and 176 with only non-specific arm pain were compared with 2,248 subjects who had no neck or arm symptoms. Certain physical risk factors were more strongly associated with specific disorders than with non-specific pain. In comparison with pain-free subjects, the odds ratios (ORs) in keyboard users (>or=1 h versus <1 h/day) were 3.1 (95% CI 1.3, 7.8) for hand-wrist tendonitis but 1.3 (0.8, 2.1) for non-specific hand-wrist pain. Other differential associations were found with age, sex, manual versus non-manual employment and smoking. Unexpectedly, low vitality was similarly associated with both specific disorders and non-specific pain. CONCLUSION: These findings suggest that the schedule may usefully distinguish disorders that differ in their association with physical risk factors.     

Effect of work with visual display units on musculo-skeletal disorders in the office environment

Background The increase in computer and mouse use has been associatedwith an increased prevalence of disorders in the neck and upperextremities. Furthermore, poor workstation design has been associatedwith an increased risk of developing these symptoms. Aim The aims of this study were (i) to estimate the prevalenceof musculo-skeletal disorders among full-time visual displayunit (VDU) users; (ii) to examine how the prevalence variesby work environment; and (iii) to explore the association withwork factors. Method A survey was carried out on the effect of work with VDUson musculo-skeletal disorders in workers in the office environmentof 56 workplaces. Office workers (n = 298), customer serviceworkers (n = 238) and designers (n = 247) were studied. Results For all the occupations combined, the 12 month prevalencesof musculo-skeletal symptoms in the neck, shoulders, elbows,lower arms and wrists, and fingers were 63, 24, 18, 35 and 16%,respectively. The study indicated that musculo-skeletal painis common among computer workers in offices. There was no strongassociation between the duration of computer work and pain orbetween the duration of mouse use and pain, but workers' perceptionof their workstation as being poor ergonomically was stronglyassociated with an increased prevalence of pain. Conclusions Musculo-skeletal symptoms are common, but the durationof daily keyboard and mouse use had no connection with musculo-skeletalsymptoms. Instead, more consideration should be paid to theergonomics of workstations, the placing of the mouse, the posturesof the upper extremities and the handling of the mouse.     

Disabling musculoskeletal pain and its relation to somatization: a community-based postal survey

BACKGROUND: Somatization (a tendency to report distress from somatic symptoms) is a little studied, but potentially important, confounder and effect modifier in occupational studies of musculoskeletal disease. AIMS: To assess the role of somatization as a risk factor for disabling regional pain. METHODS: A questionnaire was mailed to 4998 subjects of working age. Questions were asked about chronic and disabling pain in the past 12 months affecting the arm, low back, knee or combinations of these sites. Distress from physical symptoms was assessed using elements of the Brief Symptom Inventory and mental well-being was assessed using the short-form 36 (SF-36). Associations were examined by modified Cox regression and expressed as hazard ratios (HRs) with 95% confidence intervals (CI). RESULTS: Among 2632 responders, 24% reported chronic pain and 25% disabling pain at one or several sites. Risk of chronic or disabling pain increased strongly according to the number of somatic symptoms reported as bothersome. For example, the HR for chronic upper limb pain in those distressed by > or =2 somatic symptoms in the past 7 days versus none was 3.9 (95% CI 2.9-5.3), and that of disabling upper limb pain was 5.8 (95% CI 4.1-8.3). Similar patterns were found for the low back and knee, and there was a gradient of increasing risk according to the number of sites with disabling pain. In comparison, associations with SF-36 mental well-being score were weaker. CONCLUSION: Somatizing tendency should be evaluated as a possible confounder or effect modifier in studies of occupational risk factors for musculoskeletal pain.     

Musculoskeletal disorders in farmers and farm workers

Farming is a physically arduous occupation and this places farm workers at potential risk of musculoskeletal disorders such as osteoarthritis (OA) of the hip and knee, low back pain (LBP), neck and upper limb complaints, and hand-arm vibration syndrome (HAVS). This review considers the epidemiological evidence concerning such risks. The strongest evidence relates to OA of the hip, for which the public health impact is likely to be considerable. There is also weaker, but suggestive evidence that farmers more often have knee OA and LBP than workers in occupations with fewer physical demands. Tractor drivers, in particular, seem to have more LBP. Relatively little information exists on the risks of soft tissue rheumatism in the limbs and neck. For some outcomes, the link with occupational risk factors (such as heavy loading of joints and whole-body vibration) is sufficient to suggest the course that future prevention should take, but for several outcomes more research is first needed.     

Do repetitive tasks give rise to musculoskeletal disorders?

Repetitive tasks can undoubtedly cause discomfort and pain, but whether they cause or worsen the pathology causing the pain is most uncertain. Research in this area is difficult as the 'work-related upper limb disorders' do not occur exclusively in workers and because there is no simple, reliable and reproducible test for most 'work-related upper limb disorders'. Furthermore many studies are difficult to interpret as they detect disease by the presence of symptoms: one would expect manual workers to complain of more symptoms than sedentary workers and symptom aggravation does not tell one anything about the causation of the underlying pathology.     

Voice recognition products-an occupational risk for users with ULDs?

BACKGROUND: Voice recognition systems (VRS) allow speech to be converted both directly into text-which appears on the screen of a computer-and to direct equipment to perform specific functions. Suggested applications are many and varied, including increasing efficiency in the reporting of radiographs, allowing directed surgery and enabling individuals with upper limb disorders (ULDs) who cannot use other input devices, such as keyboards and mice, to carry out word processing and other activities. Aim This paper describes four cases of vocal dysfunction related to the use of such software, which have been identified from the database of the Voice and Speech Laboratory of the Massachusetts Eye and Ear infirmary (MEEI). METHOD: The database was searched using key words 'voice recognition' and four cases were identified from a total of 4800. RESULTS: In all cases, the VRS was supplied to assist individuals with ULDs who could not use conventional input devices. Case reports illustrate time of onset and symptoms experienced. CONCLUSION: The cases illustrate the need for risk assessment and consideration of the ergonomic aspects of voice use prior to such adaptations being used, particularly in those who already experience work-related ULDs.     

Sensory neural processing in work-related upper limb disorders

Pain in the upper limb is a common complaint in adults, and is often attributed to or exacerbated by occupational activities. In many patients there is no demonstrable pathology in the neck or arm to account for the symptom, and this has prompted the hypothesis that such cases might arise through abnormal neural processing of sensory information with a lowering of pain thresholds. In this paper we review the evidence in support of this theory and suggest directions for future research.     

Prevalence and occupational associations of neck pain in the British population

OBJECTIVES: This study determined the prevalence of neck pain and its relation to occupation and occupational activities in the general population. METHODS: A questionnaire was mailed to 21 201 subjects aged 16-64 years, randomly selected from the patient registers of general practices in England, Scotland, and Wales, and to 993 subjects randomly selected from pay records of the armed services. Information was collected on occupation, workplace physical activities, neck pain in the past week and year, headaches, and feelings of tiredness or stress. Associations were explored by logistic regression, the resultant odds ratios being converted to prevalence ratios (PR). RESULTS: Among 12907 respondents, 4348 and 2528 reported neck pain in past year (1421 with pain interfering with normal activities) and week, respectively. Symptoms were the most prevalent among male construction workers [past week and year 24% and 38% (pain interfering with activities 11%), respectively], followed by nurses, armed services members, and the unemployed. Generally the age-standardized prevalence of neck pain varied little by occupation. Work with arms above the shoulders for >1 hours/day was associated with a significant excess of symptoms [PR 1.3-1.7 (women) and 1.2-1.4 (men)], but no associations existed for typing, lifting, vibratory tool use, or professional driving. Stronger neck-pain associations were found with frequent headaches (PR 2.3-2.8) and frequent tiredness or stress (PR 2.2-2.5) than with occupational activities. CONCLUSIONS: The data provide evidence against a strong association between neck pain and the examined occupational physical activities. They suggest that psychosocial factors may be more important.     

Incidence and suspected cause of work-related musculoskeletal disorders, United Kingdom, 1996-2001

BACKGROUND: Musculoskeletal conditions are the most common self-reported work-related disease, with high costs incurred from long-term disability. In the United Kingdom, occupational physicians and rheumatologists have been reporting new cases of work-related musculoskeletal disorders to voluntary surveillance schemes since 1996. AIMS: To estimate population incidence rates for work-related musculoskeletal disorders reported by rheumatologists and occupational physicians by occupation and industry, in relation to tasks and movements suspected as causal. METHODS: Estimated average annual incidence rates were calculated for nine main job categories and eight industrial groups; Labour Force Survey figures were used as the denominator for rheumatologists, and a special survey for the occupational physicians. These were then related to tasks and movements reported as causal. RESULTS: Between October 1997 and the end of 2001, an estimated 2,599 new cases/year were reported by rheumatologists, and from January 1996, 5,278 cases/year by occupational physicians. Average annual rates overall were 94 per million for rheumatologists and 1,643 per million for occupational physicians (a 17-fold difference). Jobs at highest risk for the upper limb were primarily clerical, craft-related and machine work. Tasks associated with upper limb disorders and with neck and back problems were predominantly keyboard work and heavy lifting, and in craft-related occupations with gripping or holding tools. CONCLUSIONS: Jobs at risk and the associate tasks were identified which should assist prevention, but the extent to which these factors were causal or aggravating previous injury requires further study. The much higher rates reported by occupational physicians reflect, in part, the type of industries they served.     

Upper limb disorders among coopers in the Scotch whisky industry

BACKGROUND: Coopering is a physically demanding trade which has existed for >500 years. Anecdotal clinical evidence suggested increased prevalence of upper limb disorders in the population of coopers in one organization. AIMS: To investigate the prevalence of upper limb disorders in coopers and non-coopers. To identify differences in prevalence, and any relationship between the findings and the work practices. METHOD: Cross-sectional study of 108 coopers and 110 non-coopers. The Standardized Nordic questionnaire for the analysis of musculoskeletal symptoms was administered to all participants, who also underwent a clinical assessment for upper limb disorders. RESULTS: Coopers were more likely to report elbow pain in the past 12 months (OR 3.4; 95% CI: 1.8-6.2) and pain in the last 7 days (OR 4.7; 95% CI: 2.0-8.9) and this was likely to lead to prevention of activity in the past 12 months associated with the elbow (P < 0.05). Clinical evaluation highlighted a higher prevalence of upper limb disorders in coopers (OR 9.8; 95% CI: 3.9-24.3) with epicondylitis predominating (OR 8.4; 95% CI: 2.8-25.0). There was also a higher prevalence of problems in the wrist and hand among coopers (OR 8.15; 95% CI: 1.04-64; P = 0.03). Logistic regression analysis confirmed the risk of upper limb disorder in coopers (P < 0.03) accounting for age (P < 0.05) and years of service (P > 0.25). CONCLUSIONS: Coopers appear to be at an increased risk of upper limb disorders. Work practices have been reviewed and a number of changes have been implemented to reduce this risk. Further study of this group is merited in future to determine the effect of changes in work practice on the risk of upper limb disorders.     

Effect of four computer keyboards in computer users with upper extremity musculoskeletal disorders.

Eighty computer users with musculoskeletal disorders participated in a 6-month, randomized, placebo-controlled trial evaluating the effects of four computer keyboards on clinical findings, pain severity, functional hand status, and comfort. The alternative geometry keyboards tested were: the Apple Adjustable Keyboard [kb1], Comfort Keyboard System [kb2], Microsoft Natural Keyboard [kb3], and placebo. Compared to placebo, kb3 and to a lesser extent kb1 groups demonstrated an improving trend in pain severity and hand function following 6 months of keyboard use. However, there was no corresponding consistent improvement in clinical findings in the alternative geometry keyboard groups compared to the placebo group. Overall, there was a significant correlation between improvement of pain severity and greater satisfaction with the keyboards. These results provide evidence that keyboard users may experience a reduction in hand pain after several months of use of some alternative geometry keyboards.     

The Effect of Alternate Style Keyboards on Severity of Symptoms and Functional Status of Individuals with Work Related Upper Extremity Disorders

There is evidence that performing job tasks involving repetition, vibration, sustained posture or forceful movement may contribute to symptoms of work related upper extremity disorders. Typing is one such activity; symptoms that develop as a result of this activity can affect performance of work, self-care and leisure occupations. Studies investigating the impact of ergonomic keyboards on symptom reduction are limited, and little research exists regarding the reduction of key activation force as an intervention. Methods: This randomized, prospective study used a sample of 68 symptomatic workers employed by a single company. One group received a commercially available ergonomic keyboard, a second group used a modified version of the same keyboard designed to reduce activation force, vibration and key travel. We measured symptoms and clinical signs, functional status, and device satisfaction in both groups over a six-month study period. Results: Between-groups analyses indicated that the groups performed similarly on the outcomes of interest. Repeated-measure analysis identified a reduction of symptoms, an improvement in functional status, preference for and increased satisfaction with the intervention keyboards, and maintenance of typing speed and accuracy for both groups. Conclusions:     

A Comparison of Wrist Posture and Forearm Muscle Activities While Using an Alternative Keyboard and a Standard Keyboard

The wrist posture associated with the use of the conventional QWERTY keyboard is a risk factor for work-related musculoskeletal disorders in the upper limbs. Newly designed keyboards have been produced with the aim to reduce the strain in the wrist and forearm region. The present study compared the effects of using a standard keyboard and a split/angled keyboard on the forearm muscle activities and wrist joint angles. Ten subjects (6 males and 4 females) performed a standard keyboard task for 30 min, using each of the two keyboards while wrist joint angles and electromyography (EMG) were recorded. Wrist extension and ulnar deviation angles were both significantly reduced with the split/angled keyboard (p = .030 and .010), and lower EMG activities were recorded in the extensor carpi radialis and ulnaris muscles. The present results implied that the split/angled keyboard may be a better instrument for prolonged keyboard operation, resulting in reduced strain in the wrist and forearm region.     

Prevalence of upper extremity symptoms and possible risk factors in workers handling paper currency

The prevalence of upper extremity symptoms in the workforceis high, particularly in industries characterized by forceful,repetitive or awkward movements. A study was undertaken to assessthe prevalence of upper extremity symptoms in bank workers ina paper currency processing operation and to examine the roleof possible risk factors for these complaints. Thirty-nine workersof a total workforce of 47 were assessed with a questionnaireand physical examination. The questionnaire collected informationabout demographics, health status, symptom reporting, psychosocialwork stressors and other work exposure characteristics. Overall,59% of the workers reported having significant work-relatedupper extremity musculoskeletal symptoms in the preceding year,including 49% with neck and shoulder symptoms and 49% with armand wrist symptoms. In this study the key predictive factorfor upper extremity musculoskeletal symptoms was psychologicaljob demands. The workers had similar ergonomic stressors (withlittle gradient of exposure) and therefore our results do notcontradict the importance of ergonomic factors in the developmentof upper extremity symptoms. However, the results do suggestthat within a group exposed to similar ergonomic stressors,psychological job demands may be an important factor associatedwith musculoskeletal symptoms.     

Exposure to hand-transmitted vibration and pain in the neck and upper limbs.

Workers exposed to hand-transmitted vibration (HTV) often experience aches and pains in the upper limbs, but there have been few studies of the pattern and severity of symptoms, or their relationship to the estimated dose of vibration. As part of a wider survey of vibration, we mailed a questionnaire about exposures to HTV and pain in the neck and upper limbs to a sample of men selected at random from the registration lists of 34 British general practices and the pay records of the armed services. Analysis was confined to the 1856 male respondents who had been employed in manual occupations for a year or more and who reported the last week as being representative of their job. Inquiry was made about pain in the neck, shoulder, elbow and wrist/hand over the past week and past year (including pains that limited normal activity). Subjects were classed according to their lifetime exposure to HTV and their estimated average daily vibration dose [A(8) r.m.s.] in the previous week. A total of 283 men had a minimum estimated A(8) greater than a proposed action level of 2.8 m/s(2), and in this group symptoms were about twice as prevalent as in manual workers who had never used vibratory tools. The excess risk was somewhat higher for distal sites than for proximal ones (e.g. the prevalence ratio for hand/wrist pain in the past week was 2.7 versus 1.8 for neck pain). This accords with the pattern of transmission of HTV to the upper limb, although a confounding effect from other ergonomic risk factors cannot be discounted.     

Epidemiology of work related neck and upper limb problems: Psychosocial and personal risk factors (Part I) and effective interventions from a bio behavioural perspective (Part II)

Work related neck and upper limb symptoms have a multi-factorial origin. Possible risk factors are of a physical, psychosocial or personal origin. These factors can reinforce each other and their influence can also be mediated by cultural or societal factors. Initially, most research on neck and upper limb symptoms focused on work-related physical exposure. Nowadays, psychosocial work characteristics are recognized as important risk factors. Various models have been developed to offer frameworks for possible pathways, but their empirical support is still not conclusive.In part I of this paper an overview is presented of the results of recent epidemiological studies on work related psychosocial and personal risk factors for neck and upper limb symptoms. In addition, the interplay between these factors and the possible intermediate role of an individuals work style in this process is explored. In contrast to previous reviews, it is now possible to base the conclusions on the effect of work related psychosocial factors on neck and upper limb symptoms on quite a few longitudinal studies. These studies show that high work demands or little control at work are often related to these symptoms. However, this relationship is neither very strong nor very specific. Perceived stress is studied in not as many studies but more consistently related to neck and upper limb symptoms. This also applies to general distress or other pain (co-morbidity). Job dissatisfaction does not contribute to neck and upper limb symptoms. Too little research on personal characteristics is available to draw any conclusions. It is plausible that behavioural aspects, such as work style, are of importance in the etiology of work related upper limb symptoms. However, studies concerning these factors are promising but too scarce to draw conclusions. Future studies should address these behavioural aspects.In part II, the recent studies on the effectiveness of preventive measures for work related neck and upper limb problems are discussed. Few randomised or non randomised controlled trials have been carried out to evaluate the effectiveness of individual or organisational interventions to improve work related psychosocial factors. Very few have reported on the preventive effect for work related neck and upper limb symptoms. Therefore, there is a great need for additional high quality trials before any conclusions on effectiveness of bio-behavioural interventions for reduction of neck and upper limb problems and return to work after these symptoms can be made. From the low back pain intervention research can be learned that interventions should best be targeted to both the worker and the organisation and that interventions will only be successful when all stakeholders are involved.     

Musculoskeletal complaints in lock assemblers, testers and inspectors

The objectives of this study were to determine the prevalenceof musculoskeletal complaints in a population of lock assemblersin the West Midlands; to follow one group over 12 months andto explore the relationship between survey data, sickness absenceinformation and claims experience. An adapted Nordic MusculoskeletalQuestionnaire was used to determine annual and weekly prevalenceand annual disability rates for musculoskeletal complaints.There was no statistically significant difference in complaintsbetween the six companies, apart from an increased reportingof neck (p < 0.001), upper back (p < 0.001) and hip (p< 0.05) symptoms at one company (Site 4) during the weekprior to the study. When the study was repeated at Site 4 oneyear later, new employees had significantly fewer complaintsof neck and elbow discomfort over the previous year and week,but no difference in wrist complaints was reported. This surveyof lock assemblers has highlighted high levels of self-reportedupper limb complaints when compared to other referent groupsof workers.     

Effect of keyboard keyswitch design on hand pain

This randomized clinical trial evaluated the effects of keyboard keyswitch design on computer users with hand paresthesias. Twenty computer users were matched and randomly assigned to keyboard A (n = 10) or B (n = 10). The keyboards were of conventional layout and differed in keyswitch design. Various outcome measures were assessed during the 12 weeks of use. Subjects assigned keyboard A experienced a decrease in hand pain between weeks 6 and 12 when compared with keyboard B subjects (P = 0.05) and demonstrated an improvement in the Phalen test time (right hand, P = 0.006; left hand, P = 0.06). Keyboard assignment had no significant effect on change in hand function or median nerve latency. We conclude that use of keyboard A for 12 weeks led to a reduction in hand pain and an improved physical examination finding when compared with keyboard B. There was no corresponding improvement in hand function or median nerve latency.     

Symptoms experienced in connection with mobile phone use

Many people in Norway and Sweden reported headaches, fatigue, and other symptoms experienced in connection with the use of a mobile phone (MP). Therefore, we initiated a cross-sectional epidemiological study among 17,000 people, all using an MP in their job. Thirty-one percent of the respondents in Norway and 13% of those in Sweden had experienced at least one symptom in connection with MP use. Next to the sensations of warmth on the ear and behind/around the ear, burning sensations in the facial skin and headaches were most commonly reported. Most symptoms usually began during or within half an hour after the call and lasted for up to 2 h. Relatively few had consulted a physician or been on sick leave because of the symptoms, but about 45% among those with an MP attributed symptom had taken steps to reduce the symptom. These results suggest an awareness of the symptoms, but not necessarily a serious health problem.