Task engagement as a mediator between the cognitive demands of sustained attention and musculoskeletal complaints: A structural equation modelling approach.

BACKGROUND: Cognitive demands in the form of sustained attention are prevalent in automated manufacturing where operators undertake monitoring tasks for prolonged periods. Sustained attention tasks are stressful and could have potential health consequences for employees including contributing to Work Related Musculoskeletal Disorders (WRMSDs). OBJECTIVE: The study investigates if lowered task engagement (low task motivation/focus) is a mediator of the relationship between sustained attention and musculoskeletal complaints. METHOD: A structural equation modelling technique was used to determine if task engagement mediates the relationship between attention demand/attention supply and self-reported musculoskeletal complaints (MSCs) in manufacturing employees (n = 235). RESULTS: Study participants were 5.16 times (OR, odds ratio) more likely to have neck complaints, 7.27 (OR) times more likely to have upper back complaints and 3.9 (OR) times more likely to report lower back complaints (OR 2.05) when attention demands were high and task engagement was low. When task engagement was introduced as a mediator between attention supply and MSCs, odds ratios decreased for neck (from 1.01 to 0.60), shoulder (from 0.95 to 0.47) (p < 0.01), upper back (from 1.01 to 0.70) (p < 0.01) and lower back (from 0.94 to 0.40)*. CONCLUSION: Task engagement was a significant mediator of the relationship between attention demand and neck, upper back and lower back musculoskeletal complaints for study participants.

Distress and worry as mediators in the relationship between psychosocial risks and upper body musculoskeletal complaints in highly automated manufacturing.

As a result of changes in manufacturing including an upward trend in automation and the advent of the fourth industrial revolution, the requirement for supervisory monitoring and consequently, cognitive demand has increased in automated manufacturing. The incidence of musculoskeletal disorders has also increased in the manufacturing sector. A model was developed based on survey data to test if distress and worry mediate the relationship between psychosocial factors (job control, cognitive demand, social isolation and skill discretion), stress states and symptoms of upper body musculoskeletal disorders in highly automated manufacturing companies (n = 235). These constructs facilitated the development of a statistically significant model (RMSEA 0.057, TLI 0.924, CFI 0.935). Cognitive demand was shown to be related to higher distress in employees, and distress to a higher incidence of self-reported shoulder and lower back symptoms. The mediation model incorporating stress states (distress, worry) as mediators is a novel approach in linking psychosocial risks to musculoskeletal disorders. Practitioners' Summary With little requirement for physical work in many modern automated manufacturing workplaces, there is often minimal management focus on Work-Related Musculoskeletal Disorders (WRMSDs) as important occupational health problems. Our model provides evidence that psychosocial factors are important risk factors in symptoms of WRMSD and should be managed.

Inhibiting the Physiological Stress Effects of a Sustained Attention Task on Shoulder Muscle Activity.

OBJECTIVE: The objective of this study was to investigate if a breathing technique could counteract the effects of hyperventilation due to a sustained attention task on shoulder muscle activity. BACKGROUND: The trend towards higher levels of automation in industry is increasing. Consequently, manufacturing operators often monitor automated process for long periods of their work shift. Prolonged monitoring work requires sustained attention, which is a cognitive process that humans are typically poor at and find stressful. As sustained attention becomes an increasing requirement of manufacturing operators' job content, the resulting stress experienced could contribute to the onset of many health problems, including work related musculoskeletal disorders (WRMSDs). METHODS: The SART attention test was completed by a group of participants before and after a breathing intervention exercise. The effects of the abdominal breathing intervention on breathing rate, upper trapezius muscle activity and end-tidal CO2 were evaluated. RESULTS: The breathing intervention reduced the moderation effect of end-tidal CO2 on upper trapezius muscle activity. CONCLUSIONS: Abdominal breathing could be a useful technique in reducing the effects of sustained attention work on muscular activity. APPLICATION: This research can be applied to highly-automated manufacturing industries, where prolonged monitoring of work is widespread and could, in its role as a stressor, be a potential contributor to WRMSDs.