A review of physical exercises recommended for VDT operators

Efficacy of stretching exercises versus transcranial direct current stimulation (tDCS) on task performance, kinematic and electroencephalography (EEG) spectrum in subjects with slump posture: a study protocol

BACKGROUND

Slump sitting is a common posture in workplaces. There is limited evidence that poor posture impacts the mental state. This study aims to investigate whether slump posture results in more mental fatigue during computer typing, compared with normal posture and also to compare the effectiveness of stretching exercises with tDCS in fatigue monitoring.

METHODS

The sample size for this study is set at 36 participants with slump posture and 36 participants with normal posture. In the first step, to find out the differences between normal and poor posture, they will be asked to perform the typewriting task for 60 min. During the first and last 3 min of typing, mental fatigue as the primary outcome using EEG signals and further measures including kinematic behavior of neck, visual analog fatigue scale, and musculoskeletal discomfort will be assessed. Post-experiment task performance will be calculated based on typing speed and typing errors. In the next step, to compare the effect of tDCS and stretching exercises on the outcome measures, the slump posture group will receive these interventions in two separate sessions before the typing task.

DISCUSSION

With the assumption of showing significant differences in terms of outcome measures between slump and normal posture groups and also by showing the possible changes of the measures, by using either tDCS as a central modality or stretching exercises as a peripheral modality; the findings may provide evidence to indicate that poor posture has adverse effect on mental state and to introduce the effective method to overcome mental fatigue and promote work productivity.

TRIAL REGISTRATION

Registered on the Iranian Registry of Clinical Trials on 21 September 2022, IRCT Identifier: IRCT20161026030516N2.

Effects of a Traction Device for Head Weight Reduction and Neutral Alignment during Sedentary Visual Display Terminal (VDT) Work on Postural Alignment, Muscle Properties, Hemodynamics, Preference, and Working Memory Performance

The forward head posture of visual display terminal (VDT) users induces various physical and cognitive clinical symptoms. However, few studies have been conducted to identify and solve problems associated with VDT posture. This study aimed to examine the adverse effects of VDT posture and the positive effects of traction-combined workstations by measuring postural alignment, muscle properties, blood velocity, preference, and working memory. Thirty-four healthy VDT users (18 males and 16 females aged 20-30 years) participated in the experiment at three workstations, including conventional (VDT_C), head support (VDT_S), and upright (VDT_U) workstations. They conducted 2-back working memory task. The craniovertebral angle (CVA), muscle tone and stiffness, blood velocity and visual analogue discomfort scale (VADS) were measured to examine the influence of workstations. VDT_C showed increased muscle tone or stiffness in the levator scapulae (LS), suboccipital muscle (SM), and sternocleidomastoid muscle (SCM) and an increased reaction time (RT) in working memory. However, VDT_S showed decreased stiffness and tone of SM and improved comfort. In addition, VDT_U showed decreased stiffness or tone of the LS and SCM and improved blood velocity and RT. In conclusion, maintaining neutral alignment significantly improved working memory performance, muscle properties, and blood velocity.

Gender differences in prevalence of musculoskeletal disorders and physiological stress among the brick field workers of West Bengal, India

BACKGROUND

The manual brick field industry is one of the most important and oldest industries in India, where millions of male and female workers make their livelihood.

OBJECTIVE

To estimate the different ergonomic risk factors associated with brick making, identify potential gender differences and the prevalence of Work-related musculoskeletal disorders (WMSDs), physiological and psychological stress among the brickfield workers.

METHODS

Brickfield workers - 152 male and 148 female were randomly selected from the 12 brickfields. The Modified Nordic Questionnaire was applied to assess the discomfort reported among both groups of brickfield workers. Objective measurement of physiological parameters and lung function values were also recorded.

RESULTS

From this study, it was revealed that there is significantly higher discomfort reported in hands, lower back and knees among female brick molders than male brick molders. The physiological parameters did not show any significant change between male brickfield workers and female brickfield workers. The mean values of FVC, FEV1 and PEFR for females were lower than those for male brickfield workers.

CONCLUSION

This study concludes that female brickfield workers reported more discomfort than male brickfield workers; perhaps in part due to their additional domestic work responsibilities.

Cumulative trauma disorders: A review

BACKGROUND

Cumulative trauma disorder (CTD) is a term for various injuries of the musculoskeletal and nervous systems that are caused by repetitive tasks, forceful exertions, vibrations, mechanical compression or sustained postures. Although there are many studies citing incidence of CTDs, there are fewer articles about its etiology, pathology and management.

OBJECTIVE

The aim of our study was to discuss the etiology, pathogenesis, prevention and management of CTDs.

METHODS

A literature search was performed using various electronic databases. The search was limited to articles in English language pertaining to randomized clinical trials, cohort studies and systematic reviews of CTDs.

RESULTS

A total of 180 papers were identified to be relevant published since 1959. Out of these, 125 papers reported about its incidence and 50 about its conservative treatment.

CONCLUSIONS

Workplace environment, same task repeatability and little variability, decreased time for rest, increase in expectations are major factors for developing CTDs. Prevention of its etiology and early diagnosis can be the best to decrease its incidence and severity. For effective management of CTDs, its treatment should be divided into Primordial, Primary, Secondary and Tertiary prevention.

Workplace exercise for control of occupational neck/shoulder disorders: a review of prospective studies

A review was conducted of prospective studies (1997-2014) examining the efficacy of exercise as a workplace intervention to control neck/shoulder pain, symptoms, and disability. The review identified 38 relevant studies - 20 were classified with positive effects, 13 with null effects, and 5 as inconclusive. Of the positive studies, 12 were consistent with Level I evidence, 3 with Level II evidence, and 5 with Level IV evidence. Specific resistance training (SRT) exercise appeared to be associated with more positive studies (eight Level I studies) than other exercise modalities such as general resistance training, general physical exercise, stretching, and movement awareness exercises. Studies of longer trial duration tended toward more null findings and lower program compliance. Evidence for a primary preventive effect of workplace exercise is minimal. The findings of this review suggest that workplace exercise can be effective as tertiary prevention and therapeutic relief of neck/shoulder symptoms, at least over the shorter term.

Efficacy of a telerehabilitation intervention programme using biofeedback among computer operators

Computer operators spend long periods of time sitting in a static posture at computer workstations and therefore have an increased exposure to work-related musculoskeletal disorders (WRMSD). The present study is aimed at investigating the feasibility and effectiveness of a tele-biofeedback ergonomic intervention programme among computer operators suffering from WRMSD. Twelve subjects with WRMSD were assigned an ergonomic intervention accompanied by remote tele-biofeedback training, which was practised at their workstations. Evaluations of pain symptoms and locations, body posture and psychosocial characteristics were carried out before and after the intervention in the workplace. The hypothesis was partially verified as it showed improved body position at the workstation and decreased pain in some body parts. Tele-biofeedback, as part of an intervention, appears to be feasible and efficient for computer operators who suffer from WRMSD. This study encourages further research on tele-health within the scope of occupational therapy practice. Practitioner summary: Research concerning tele-health using biofeedback is scarce. The present study analyses the feasibility and partial effectiveness of a tele-biofeedback ergonomic intervention programme for computer operators suffering from WRMSD. The uniqueness and singularity of this study is the usage of remote communication between participants and practitioners through the Internet.

Screen based keyboard operation: the adverse effects on the neural system

The effect of screen based keyboard (SBK) operation on extensibility of the neural system was investigated using the radial nerve upper limb tension test (Butler 1991). Twenty-five female subjects (aged 17-55 years) including 15 SBK operators and 10 non-SBK operators who acted as a control were examined. Mean glenohumeral abduction in the upper limb tension test in the control group was 40 degrees. In the SBK operators, it was 27 degrees (right side) and 30 degrees (left side). Statistical analysis showed a significant difference between the groups. Results indicate that the normal mechanics of the neural system may be affected by SBK operation and that neural tension warrants consideration in the prevention and management of work related neck and upper limb disorders.

Stress management as an adjunct to physical therapy for chronic neck pain

BACKGROUND AND PURPOSE

Chronic neck pain is prevalent in the workplace. Research suggests that psychosocial stress may contribute to the development of neck pain by causing excessive or prolonged muscle activity in some individuals. The purpose of this case report is to describe the rationale, development, and implementation of stress management as an adjunct to standard physical therapist management of chronic neck pain in a female office worker who responded to psychosocial stress with elevated muscle activity prior to treatment.

CASE DESCRIPTION

A 44-year-old female office employee with an 8-year history of chronic neck pain participated in this case report. The patient was selected from a group of research participants who demonstrated elevated electromyographic (EMG) activity of the trapezius muscle in response to simulated occupational stressors. The multidisciplinary intervention consisted of 8 physical therapy sessions, supplemented by 8 stress management sessions that included EMG biofeedback and psychotherapy to facilitate muscle relaxation.

OUTCOMES

Neck disability decreased by 50%, trait anxiety decreased by 21%, and the duration of trapezius muscle rest in the workplace increased by 56% immediately after the 8-week intervention. These improvements were maintained 6 months after treatment, and the patient reported a complete absence of neck disability at the 2-year follow-up assessment.

DISCUSSION

A sustained reduction in neck disability was observed for a patient with chronic neck pain after participating in a multidisciplinary intervention that combined physical therapy and stress management approaches to facilitate muscle relaxation in the workplace. Future clinical trials are needed to assess whether stress management is a useful adjunct therapy for patients with chronic neck pain who show elevated muscle activity in response to psychosocial stress.

Prevention of upper limb symptoms and signs of nerve afflictions in computer operators: The effect of intervention by stretching

BACKGROUND

In a previous study of computer operators we have demonstrated the relation of upper limb pain to individual and patterns of neurological findings (reduced function of muscles, sensory deviations from normal and mechanical allodynia of nerve trunks). The identified patterns were in accordance with neural afflictions at three specific locations (brachial plexus at chord level, posterior interosseous and median nerve on elbow level). We have introduced an intervention program aiming to mobilize nerves at these locations and tested its efficacy.

METHODS

125 and 59, respectively, computer operators in two divisions of an engineering consultancy company were invited to answer a questionnaire on upper limb symptoms and to undergo a blinded neurological examination. Participants in one division were subsequently instructed to participate in an upper limb stretching course at least three times during workdays in a six month period. Subjects from the other division served as controls. At the end of the intervention both groups were invited to a second identical evaluation by questionnaire and physical examination. Symptoms and findings were studied in the right upper limb. Perceived changes of pain were recorded and individual and patterns of physical findings assessed for both groups at baseline and at follow-up. In subjects with no or minimal preceding pain we additionally studied the relation of incident pain to the summarized findings for parameters contained in the definition of nerve affliction at the three locations.

RESULTS

Summarized pain was significantly reduced in the intervention group but unchanged in controls. After the intervention, fewer neurological abnormalities in accordance with nerve affliction were recorded for the whole material but no conclusion could be drawn regarding the relation to the intervention of this reduction. Incident pain correlated to findings in accordance with the three locations of nerve affliction.

CONCLUSION

A six month course of stretching seems to reduce upper limb symptoms in computer operators but we could not demonstrate an influence on neurological physical findings in this sample. The relation of incident symptoms to identified neurological patterns provides additional support to the construct validity of the employed neurological examination.

Supplementary breaks and stretching exercises for data entry operators: a follow-up field study

BACKGROUND

This study expanded previous NIOSH-IRS research examining the effects of rest breaks and stretching exercises on symptoms and performance in data-entry workers.

METHODS

All workers spent 4 weeks with conventional breaks (two 15 min breaks per day) and 4 weeks with supplementary breaks (two 15 min breaks plus four 5 min breaks per day). One-half were assigned at random to a group instructed to perform brief stretching exercises during breaks. The remainder comprised the "no stretching" (control) group.

RESULTS

51 workers (stretch group n = 21; no stretch group n = 30) completed the study symptom questionnaires. Discomfort and eyestrain were significantly lower with supplementary breaks, and supplementary breaks attenuated accumulation of discomfort and eyestrain during work sessions. Data-entry speed was significantly faster with supplementary breaks so that work output was maintained, despite replacing 20 min of work time with break time. In the stretch group, workers reported stretching during only 25% of conventional breaks and 39% of supplementary breaks, and no significant effects of stretching on discomfort or performance were observed.

CONCLUSIONS

These results provide further converging evidence that supplementary breaks reliably minimize discomfort and eyestrain without impairing productivity. Low compliance in performing stretches prevented valid assessment of stretching effects. Further research on stretching exercises and exercise compliance is warranted.

Short-Term Effects of Workstation Exercises on Musculoskeletal Discomfort and Postural Changes in Seated Video Display Unit Workers

Background and Purpose. In recent years, a number of exercise programs have been developed for computer operators in order to promote movement and to reduce musculoskeletal discomfort. Tests of the effectiveness of these exercise programs, especially in field trials, are rare. The authors tested the hypothesis that doing regular, short-term (<10 days) exercises while at a workstation would decrease musculoskeletal discomfort and increase in-chair movement (ICM). Subjects. Eleven directory assistance operators (8 female, 3 male) with no recent history of musculoskeletal problems volunteered. Methods. In-chair movement was measured by tracking the center of pressure at the buttock-chair interface as subjects sat on a pressure-sensitive mat. Musculoskeletal discomfort was rated through the use of the Body Part Discomfort Scale (BPDS) and a body map. We used a revised Dataspan exercise program. Operators were tested for 2 hours, on 2 occasions: before and after doing exercises for 3- to 5-day shifts. During each test, ICM was measured during three 15-minute periods at the start of the test and at the end of hours 1 and 2. Subjects rated musculoskeletal discomfort per body part using the BPDS at 30, 60, and 120 minutes of each test. The effects of exercises on ICM and BPDS ratings were examined with a two-way repeated-measures analysis of variance with day (2) × time (3) designs. Results. When subjects were doing their exercises, ICM was higher at the start and hour 1, and perceived discomfort was lower during each test period (start, hour 1, and hour 2). When not exercising, subjects' musculoskeletal discomfort increased over time and was higher during all test periods. Discussion and Conclusion. Exercises done by video display unit operators while at a workstation resulted in short-term decreases in both musculoskeletal discomfort and postural immobility. These results suggest that workstation exercises may be beneficial.

A case study in iterative keyboard design using participatory design techniques

Replacing a keyboard can be stressful for operators who take calls all day, particularly when special functions must be sacrificed. This study applied several participatory design techniques to involve over 3,000 operators in the redistribution of function keys on their replacement keyboard. Video analysis and manual data logging methods were surprisingly accurate when measured against software logs. User acceptance was excellent. In the initial cutover program, operator performance levels returned to normal very quickly, resulting in over-confidence and unrealistic expectations of post-implementation performance for the remaining call centres because the focus was on the technology rather than on the impact of technology on business benefits. As a consequence, business plan requirements for future projects have now been changed to accommodate predictions of post-implementation performance and taking into account other changes happening at the same time.

Repetitive strain injuries

Repetitive strain injuries (RSI) present an increasingly common challenge to clinicians. They consist of variety of musculoskeletal disorders, generally related to tendons, muscles, or joints, as well as some common peripheral-nerve-entrapment and vascular syndromes. These disorders generally affect the back, neck, and upper limbs, although lower limbs may also be involved. Although RSI may occur as a result of sports and recreational activities, occupational RSIs, affecting the patient's livelihood, are particularly important. These injuries result from repetitive and forceful motions, awkward postures, and other work-related conditions and ergonomic hazards. Occupationally induced RSIs are generally costly, creating a strong incentive for physicians to become familiar with the symptoms, signs, and risk factors so that they can be diagnosed early and appropriate interventions facilitated.

Improving marketability of exercise programs: implications for health promotion in the workplace

Musculoskeletal stress due to sedentary work has been a problem in workplaces. Exercise programs are available to help alleviate such stress; however, they have been adopted by few companies. The acceptability of these problems, that is their "marketability" will be enhanced if employee preferences regarding exercise in the workplace are taken into account during their design. A questionnaire was administered to employees engaged in sedentary work to determine employees' preferences about exercise programs in the workplace. Respondents preferred exercises that are targeted for specific body parts, have easy-to-follow instructions, are somewhat difficult but more beneficial, and can be completed in a private room. Marketability of exercise programs may be improved by focusing on these characteristics.

An exploratory study of the relationship between biomechanical factors and right-arm musculoskeletal discomfort and fatigue in a VDT data-entry task

The relationship of key force and keystroke rate with right-arm musculoskeletal discomfort and fatigue was explored in a video-display-terminal (VDT) data-entry task. Forty-three data transcribers entered bogus data from tax forms at a VDT for one workday with their right hand. Peak key force and keystroke rate were monitored on a continuous basis. Self-ratings of right-arm discomfort and fatigue were assessed at periodic intervals. Stepwise regression analyses indicated that both lower key forces and lower keystroke rates were associated with higher ratings of right-elbow discomfort. In addition, lower key forces were associated with higher ratings of right-hand discomfort and lower keystroke rates were associated with higher ratings of right-shoulder discomfort and fatigue. The amount of variance accounted for by these models ranged from 7 to 24%. These results appear to be contrary to conventional biomechanical models that postulate a positive association between key force, keystroke rate and musculoskeletal discomfort in VDT work. Further laboratory and field research under controlled conditions is needed to clarify the direction and extent of the cause-and-effect relationship between biomechanical factors and musculoskeletal discomfort in VDT data-entry work.