Age as a moderator in the relationship between work-related characteristics,job dissatisfaction and need for recovery

Job dissatisfaction and need for recovery are associated with voluntary turnover, absenteeism and diminished health. In the light of encouraging working longer, this study investigated whether the relationships between various work characteristics and job dissatisfaction and need for recovery are dependent on age. Cross-sectional questionnaire data from 591 university employees were divided into four age groups: < 36, 36–44, 45–54 and ≥ 55 years. Multivariate regression analyses were used, including interaction variables to detect a moderating effect of age group. Limited age group effects were found: only the association of Feedback with job dissatisfaction and Task variety with need for recovery were influenced by age group. The salience of specific work characteristics within the age groups varied: for job dissatisfaction, Task variety ( < 55) and Changes in tasks ( ≥ 55) were most important. For need for recovery, this applied to Autonomy ( < 36) and Workload ( ≥ 45). To encourage working longer, age-specific measures could be considered, in addition to individual measures, to respond to individual needs.

Practitioner summary: Demographic changes increase the importance to stimulate working longer. Using questionnaire data, we investigated the relationship between work characteristics, job dissatisfaction and need for recovery in four age groups. Although the moderating effect of age group was rather limited, the salience of specific work characteristics within the age groups varied.     

Psychosocial work characteristics,need for recovery and musculoskeletal problems predict psychological distress in a sample of British workers

From an original sample of 2454 participants free of self-reported psychological distress, 1463 workers completed a 15-month follow-up. Baseline measures included exposure to job demands, decision latitude, social support and need for recovery. Psychological distress was assessed using the General Health Questionnaire at baseline and at follow-up. The findings showed that medium and high exposure to job demands and social support increased the risk of reporting psychological distress at 15-months (relative risk (RR) = 1.65, 1.45). The highest adjusted RR was observed for workers reporting a high need for recovery after work (RR 2.12, 1.90) and this finding was independent of the effects of job demands, decision latitude and social support. Neither decision latitude, nor low back problems increased the risk of reporting future psychological distress, although neck problems (RR = 1.66) and hand/wrist problems (RR = 1.45) did. It was concluded that need for recovery appears to be an important indicator of individual workers who are at risk of developing psychological distress long term.

Statement of Relevance: This paper reports the findings of a longitudinal study showing that need for recovery from work was the strongest predictor, relative to psychosocial work characteristics (job demands, decision latitude and social support), and musculoskeletal problems, of psychological distress 15 months later in individuals initially free from distress.     

Association of job strain with working hours,shift-dependent perceived workload,sleepiness and recovery

We explored the relationship of job strain with working hours, shift-dependent perceived workload, sleepiness and recovery. Nurses/nursing assistants (n = 95) were recruited from wards that belonged to either the top (high-strain group, HJS) or the bottom (low-strain group, LJS) job strain quartiles of a Job Content Questionnaire survey of employees in five health care districts and four cities in Finland. Three-week field measurements during naturally occurring shift schedules and a subset of pre-selected shift arrangements consisted of the Karolinska Sleepiness Scale, perceived workload and recovery. The HJS group (n = 42) had more single days off and quick returns than the LJS group (n = 53, p < 0.01), and both mental workload and physical workload were rated as higher (p < 0.01). During naturally occurring shift arrangements, severe sleepiness was more common in the HJS group only in quick returns (p = 0.04) and the HJS group recovered on average more poorly from work after all shifts (p = 0.01) and morning shifts (p = 0.02). During pre-selected shift arrangements, the differences between the groups were only minor. In conclusion, job strain-related differences in sleepiness and recovery were mostly attributable to differences in shift arrangements.     

Efficacy of adjusting working height and mechanizing of transport on physical work demands and local discomfort in construction work

The efficacy of ergonomics measures to reduce physical work demands in a real working situation is often assumed, but seldom studied. In this study, the effect of adjusting working height and mechanization of transport on physical work demands and local discomfort of bricklayers' work was evaluated during a field experiment in the construction industry. In a within-subjects controlled experiment, 10 bricklayers and 10 bricklayers' assistants worked in two different conditions. Working height of bricks and mortar, and transport of materials were manipulated. The physical work demands were assessed through real time observations at the work site. Local discomfort of the lower back and of the shoulder region was measured by means of a visual analogue scale. Working with a scaffolding console to adjust the working height of the storage of materials resulted in a significant reduction of the frequency and duration of trunk flexion (?>?60°) by 79% and 52% respectively, compared with bricks set out on the ground floor. Mechanization of transport of materials resulted in a significant reduction of the frequency and duration of trunk flexion (?>?60°) by 94% and 92% respectively, compared with the condition of manual handling. The frequency of handling objects (?>?4?kg) reduced significantly by 86%. Local discomfort of the lower back was significantly less in the ergonomic conditions, while no significant difference was found for local discomfort of the shoulder between both conditions in bricklayers' assistants.     

On-site observations of physical work demands of train conductors and service electricians in the Netherlands

The objective of the present study was to assess the exposure to physical work demands of train conductors and service electricians at a railway company in the Netherlands. On-site observations were performed using the Task Recording and Analysis on Computer observation system to identify the mean duration and frequency of tasks, activities and body postures. In total, 36 train conductors and 41 service electricians were observed for a net working day of 7 h. Results showed that train conductors and service electricians climbed a flight of stairs on average 249 and 258 times, respectively, and that service electricians worked above shoulder height for 65 min on average. In both jobs, guidelines were exceeded, e.g. duration of standing, the number of times climbing a flight of stairs, kneeling and squatting or working in awkward postures, which are risk factors for developing musculoskeletal complaints. Suggestions are made concerning how to reduce these risk factors.

Statement of Relevance: Understanding physical work demands is essential for recognising risk factors for musculoskeletal disorders. Since train conductors and service electricians in the Netherlands reported work-related complaints, on-site observations were performed to determine the duration and frequency of physical work demands. Risk factors were identified in both professions, providing insights concerning preventative measures.     

A convenient prediction model for complete recovery time after exhaustion in high-intensity work

We aimed to propose a convenient model for predicting complete recovery time (CRT) after exhaustion in high-intensity work. Before participating in the laboratory test, each of the 47 young adult subjects provided demographic information and filled out the perceived functional ability (PFA) and physical activity rating (PA-R) questionnaires. All subjects were required to perform one cycling test (at 70% maximum working capacity). Subjects continued cycling until exhaustion and then sat and recovered until their heart rates (HR) returned to baseline values. We found that CRT was significantly correlated with relative body mass index, the PFA score, PA-R score and maximum heart rate (HR_max). Accordingly, a prediction model for CRT was proposed. Furthermore, by replacing HR_max with age-predicted maximal HR, we obtained a more convenient prediction model that was independent of any physiological indexes that can only be obtained by subject testing.     

Stand up: comparison of two electrical screed levelling machines to reduce the work demands for the knees and low back among floor layers

Electrical screed levelling machines are developed to reduce kneeling and trunk flexion of sand–cement-bound screed floor layers. An observational intervention study among 10 floor layers was performed to assess the differences between a self-propelled and a manually moved machine. The outcome measures were work demands, production time, perceived load, discomfort and applicability. Compared to the self-propelled machine, the duration of kneeling (?13 min; p = 0.003) and trunk flexion (?12 min; p < 0.001) was shorter using the manually moved machine, and the duration of pushing and pulling increased (?39 min; p < 0.001). No significant or relevant differences were found for production time, perceived load and discomfort. Nine out of ten floor layers found the manually moved machine applicable and three out of ten found the self-propelled machine applicable. When compared with the traditional manner of floor laying, both electrical machines reduced the exposure towards kneeling and trunk flexion.

Practitioner Summary: Electrical machines may help to reduce high physical work demands on floor layers. A manually moved machine is better applicable for the installation of screed floors in residences with smaller floor areas. A self-propelled machine is better applicable on large floor areas with a minimum width of 4 m.     

提高农民科技需求对策研究

科技进步是农业发展的根本出路,农民对科技的需求,是农业科技发展的动力因素之一。本文通过对农民科技需求的动力因素和发展趋势的分析,找出提高农民科技需求的难点,并提出相应的对策．     

Physical demands of work and health complaints among women working late in pregnancy

Health complaints before, during and after pregnancy were collected from 2251 women in Montreal who had been in paid employment beyond the twenty-seventh week of their first or second pregnancy. Complaints of breathlessness, fatigue, back pain, varicose veins and haemorrhoids increased during pregnancy, the proportion of women reporting these symptoms being greatest in the third trimester. Complaints at this stage were found to be systematically related to job postures and other physical work demands, prolonged periods of standing, particularly with the back bent forward, twisting the trunk and lifting weights all being found troublesome by workers late in their pregnancy. Three months after delivery the level of health complaints had generally returned to that before pregnancy. This was so for all symptoms except varicose veins and haemorrhoids. No relation was found between trouble with haemorroids and the physical demands of work in pregnancy. Problems with varicose veins three months after delivery were however, more frequent than expected in those whose job had required them to stand during pregnancy for more than 2h at a stretch. There was also some indication that women in physically demanding jobs took longer to recover from their confinement.     

Workers' intrinsic work motivation when job demands are high: The role of need for autonomy and perceived opportunity for blended working

Work overload or work pressure may undermine workers' intrinsic motivation. In the present research, we tested the conditions under which this may (not) occur, including the perceived opportunity to blend on-site and off-site working through the effective use of computers and modern information and communication technology. Our sample consisted of 657 workers (51% female) representing a variety of industries. As hypothesized, it is not high job demands per se, but high demands in combination with a high need for autonomy and a lack of perceived opportunities for blended working that undermines intrinsic work motivation. When workers high in need for autonomy perceived opportunities for blended working, their intrinsic work motivation was not negatively affected by increasing job demands. This main finding suggests that, particularly for workers high in need for autonomy, the perceived opportunity for blended working is an effective, contemporary resource to cope with the increasing job demands typically observed in today's workplace. Theoretically, these findings contribute to the refinement and extension of influential demands-resource models and Person-Job Fit theory. Practically, our findings may show managers how to effectively keep workers intrinsically motivated and productive in their jobs when job demands are high.     

Quantitative analysis of heart rate recovery profile during recovery from physical work

A mathematical model depicting a person's heart rate profile during the recovery period was developed. This model consisted of two heart rate parameters, namely, a resting heart rate (HRR) and a heart rate increase (ΓHR), and a model parameter (ß) representing the recovery rate of heart rate. A load-carrying experiment was conducted to study the following: (1) the relationship between work load and the recovery rate of heart rate, and (2) the possibility of using the model to estimate a person's heart rate recovery profile. From the experiment, heart rate recovery profiles from fourteen subjects were recorded and their recovery rates were determined. The results showed that for the load carrying activity the recovery rate of heart rate linearly correlated with work load; the higher the work load, the faster the recovery rate was. Furthermore, when comparing the heart rate recovery profiles estimated by the model to those previously recorded, remarkable similarities were found at every work load studied.     

Evaluation of the effect of a paver’s trolley on productivity, task demands, workload and local discomfort

The objective of this study was to determine the differences in the number of paving stones laid (productivity), task demands, energetic workload, body region discomfort and preference when laying paving stones with or without use of a paver’s trolley (n = 8) in a within-subject controlled study of pavers. The number of paving stones laid and the task demands were measured by means of systematic observations at the workplace. The energetic workload was determined using the percentage of heart rate reserve (%HRR). Body region discomfort was measured using visual analog scales, and the workers’ preference was ascertained via interview. The use of a paver’s trolley had no effect on productivity, %HRR or body region discomfort compared to working without a paver’s trolley. The duration of knee-straining activities did not differ between working with (141 min) and without (146 min) the paver’s trolley. However, six of the eight pavers indicated that, given suitable circumstances, they wanted to use the paver’s trolley.

Relevance to industry

To reduce the chance of work-related low back and knee complaints among pavers, the duration, frequency and intensity of lower back and knee-straining activities should be limited by means of technical measures such as mechanical paving. The paver’s trolley does not appear to reduce knee-straining activities and therefore does not appear useful in reducing the risk of knee complaints and disorders.     

Evaluation of team lifting on work demands,workload and workers' evaluation: An observational field study

The objective of this study was to assess differences in work demands, energetic workload and workers’ discomfort and physical effort in two regularly observable workdays in ironwork; one where loads up to 50 kg were handled with two persons manually (T50) and one where loads up to 100 kg were handled manually with four persons (T100). Differences between these typical workdays were assessed with an observational within-subject field study of 10 ironworkers. No significant differences were found for work demands, energetic workload or discomfort between T50 and T100 workdays. During team lifts, load mass exceeded 25 kg per person in 57% (T50 workday) and 68% (T100 workday) of the lifts. Seven ironworkers rated team lifting with two persons as less physically demanding compared with lifting with four persons. When loads heavier than 25 kg are lifted manually with a team, regulations of the maximum mass weight are frequently violated.     

Effect of block weight on work demands and physical workload during masonry work

The effect of block weight on work demands and physical workload was determined for masons who laid sandstone building blocks over the course of a full work day. Three groups of five sandstone block masons participated. Each group worked with a different block weight: 11 kg, 14 kg or 16 kg. Productivity and durations of tasks and activities were assessed through real time observations at the work site. Energetic workload was also assessed through monitoring the heart rate and oxygen consumption at the work site. Spinal load of the low back was estimated by calculating the cumulated elastic energy stored in the lumbar spine using durations of activities and previous data on corresponding compression forces. Block weight had no effect on productivity, duration or frequency of tasks and activities, energetic workload or cumulative spinal load. Working with any of the block weights exceeded exposure guidelines for work demands and physical workload. This implies that, regardless of block weight in the range of 11 to 16 kg, mechanical lifting equipment or devices to adjust work height should be implemented to substantially lower the risk of low back injuries.     

Testing the moderating role of need for cognition in smartphone adoption

While numerous studies have identified various cognitive and social factors affecting the adoption of new technologies and innovations, the role of individual differences has not yet received full research attention. In this study, we focused on the need for cognition (NFC; Cacioppo, J.T. and Petty, R.E., 1982. The need for cognition. Journal of Personality and Social Psychology, 42, 116–131) and examined the implications of this personality variable relative to smartphone use. The results based on the survey data (N=411) provided support for our hypotheses that NFC is an important motivational personality construct that distinguishes between adopters and non-adopters of smartphones. We also found that NFC moderates the linkages between instrumental beliefs, social influence factors, and behavioural intentions (BI). Specifically, perceived usefulness had a stronger effect on BI for high-NFC people, whereas perceived ease of use and subjective norms had stronger effects for low-NFC people. The findings reveal possible important variations in technology adoption and the role of NFC in governing these alternative decision-making processes. Implications for theory, product design, as well as for managers are discussed.     

The evaluation of smaller plasterboards on productivity, work demands and workload in construction workers

Manual handling of plasterboards in order to construct interior building walls is a risk factor for musculoskeletal complaints. Unfortunately, mechanical lifting aids to reduce the physical workload are impractical for this task. Therefore, the effect of smaller plasterboards on productivity, work demands and workload was evaluated in an exploratory study among experienced construction workers (n=4-8) at the worksite. The dimensions and weight of the conventional and smaller plasterboards (PB) were: PB120 (2440 x 1200 x 15 mm; 33 kg) and PB90 (2440 x 900 x 12.5 mm; 20 kg), respectively. Productivity was defined as meters of plasterboard mounted. Work demands were assessed by means of real time observations of tasks and activities. Workload was determined using continuous heart rate monitoring and subjective judgments of perceived workload. Productivity and total work time per working day did not differ between PB120 and PB90. Duration of mounting (29% increase) and anchoring (26% increase) were longer for PB90 than PB120. Duration of lifting, carrying and turning over plasterboards, and percentage of heart rate reserve showed no difference between PB120 and PB90. A majority of the workers preferred PB90. For the last two reasons and because PB90 weighs approximately 40% less than PB120, PB90 seems preferable. The workload in both conditions, however, was considered high.     

Designing sustainable work systems: The need for a systems approach

There is a growing discussion concerning sustainability. While this discussion was at first mainly focused on a society level – and sometimes regarding especially environmental problems, one can now see that this topic is of increasing relevance for companies worldwide and even the social dimension of this three pillar approach is gaining more and more importance. This leads to some questions: Is sustainability already a part of human factors thinking or do we have to further develop our discipline? How can we define sustainable work systems? What are the topics we have to consider? Do we need a new systems ergonomics perspective regarding whole value creation chains and a life-cycle perspective concerning products (and work systems)? How can we deal with potential contradictions about social, ecological, and economic goals?     

Functional work breaks in a high-demanding work environment: an experimental field study

Work breaks are known to have positive effects on employees’ health, performance and safety. Using a sample of twelve employees working in a stressful and cognitively demanding working environment, this experimental field study examined how different types of work breaks (boxing, deep relaxation and usual breaks) affect participants’ mood, cognitive performance and neurophysiological state compared to a control condition without any break. In a repeated measures experimental design, cognitive performance was assessed using an auditory oddball test and a Movement Detection Test. Brain cortical activity was recorded using electroencephalography. Individual’s mood was analysed using a profile of mood state. Although neurophysiological data showed improved relaxation of cortical state after boxing (vs. ‘no break’ and ‘deep relaxation’), neither performance nor mood assessment showed similar results. It remains questionable whether there is a universal work break type that has beneficial effects for all individuals.

Practitioner Summary: Research on work breaks and their positive effects on employees’ health and performance often disregards break activities. This experimental field study in a stressful working environment investigated the effect of different work break activities. A universal work break type that is beneficial for this workplace could not be identified.     

Work content and satisfaction before and after a reorganisation of data entry work

The aim of the study was to analyse the psychosocial and physical effects of a reorganisation of data entry work at a data processing unit with 153 employees. The reorganisation was planned to redistribute the repetitive work and improve health and satisfaction as well as efficiency. Methods used were questionnaires and, for a sub-group of 22 participants, interviews, diaries and video recordings. During the one-and-a-half-year study period the data processing unit was closed down and the employees transferred to units with more varied tasks. The reorganisation gave opportunities to improve working conditions. The results of this study show that important improvements were achieved. The majority of the 22 participants got less data entry work and the changes permitted a better work-load distribution. However, the work content after the reorganisation still did not provide satisfactory mental variation for most of the subjects, and the changes did not seem to affect health complaints.