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Increased physical work loads in modern work – anecessity for better health and performance?Leon Straker a & Svend Erik Mathiassen ba School of Physiotherapy, Curtin University of Technology , Perth, Australiab Centre for Musculoskeletal Research, University of Gavle , SwedenPublished online: 21 Oct 2010.

To cite this article: Leon Straker & Svend Erik Mathiassen (2009) Increased physical work loads in modern work – a necessityfor better health and performance?, Ergonomics, 52:10, 1215-1225, DOI: 10.1080/00140130903039101

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Increased physical work loads in modern work – a necessity for better health and performance?

Leon Strakera* and Svend Erik Mathiassenb

aSchool of Physiotherapy, Curtin University of Technology, Perth, Australia; bCentre for Musculoskeletal Research,University of Gavle, Sweden

Shifting workforce proportions to sedentary occupations and technology developments in traditionally physicallydemanding occupations have resulted in low physical workloads for many workers. Insufficient physical stress isknown to have detrimental short- and long-term effects on health and physical capacity. It is argued herein thatmany modern workers are at risk of insufficient physical workload. Further, it is argued that the traditional physicalergonomics paradigm of reducing risk by reducing physical loads (‘less is better’) is not appropriate for manymodern occupations. It is proposed that a new paradigm is required, where ‘more can be better’. The potential forwork to be seen as an arena for improving physical health and capability is discussed and the types of changes towork that may be required are outlined. The paper also discusses challenges and responsibilities presented by thisnew paradigm for ergonomists, employers, health and safety authorities and the community. The majority ofworkers in affluent communities now face the significant threat to health of insufficient physical workload.Ergonomics can design work to a prescription that can not only reduce injury risk but enhance health and capacity.However, this will require a change in paradigm.

Keywords: physical activity; stress; musculoskeletal injury; physical workload; health promotion

1. Working life is becoming more physically inactive

for many

The physical loads of working life have changed formany workers. Proportionally, more people are nowemployed in workforce sectors characterised bycomparatively low physical loads (such as retailingand tourism) and this trend is expected to continue(Statistics Sweden 2005). Furthermore, those sectorsthat previously contained many jobs with heavyphysical loads have undergone a transition towardsless strenuous work, both because of successful healthand safety interventions and because of technicaldevelopments to increase productivity. Forestry is anexample of this transformation. From 1960 to 1990 thenumber of employees in Swedish forestry fell by two-thirds, from 67,000 to 21,000. In parallel, timbercutting and loading changed from a demanding whole-body task with considerable cardiovascular load(Kurumatani et al. 1992, Hagen et al. 1993) to seatedoperation of forest machines, requiring less than 5% ofmaximal muscular capacity (Axelsson and Ponten1990, Attebrant et al. 1997).

The rise of the information economy has beenaccompanied by a spectacular increase in work tasks

focused around sitting at a computer. For example, in1994 only 43% of Australian businesses usedcomputers but this had increased to 83% by 2003(Australian Bureau of Statistics 2003). Similarly, in1991 only 40% of the Swedish working populationused computers at work, yet by 2005 this hadincreased to about 70% (Official Statistics of Sweden2005).

Sedentary office work in general, and computerwork in particular, is associated with low physicalstresses, including negligible circulatory demands(Klucharev et al. 2000, Hjortskov et al. 2004) andmedian muscle activities in the shoulder and lower armin the order of or less than 5% of maximal capacity(Bystrom et al. 2002, Blangsted et al. 2003, Won et al.2009). A recent study on air traffic controllers using acomputer-based communication system found almost50% of the working time was spent with the uppertrapezius muscle at rest (Arvidsson et al. 2006). Studiesof ordinary office work have reported very lowtrapezius activity for up to about 20% of the workingday (Mathiassen et al. 2003). Since the trapeziusmuscle is active during most movements of the body,these results suggest that the workers were inactive for

*Corresponding author. Email: l.straker@curtin.edu.au

Ergonomics

Vol. 52, No. 10, October 2009, 1215–1225

ISSN 0014-0139 print/ISSN 1366-5847 online

� 2009 Taylor & Francis

DOI: 10.1080/00140130903039101

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substantial parts of the day. Schofield et al. (2005)found that New Zealand office workers walked around5400 steps at work, which was about half as much asblue collar workers (10,300 steps). Similarly, Eggeret al. (2001) reported actors in a living museum of lifein the nineteenth century walked the equivalent of8 km per day more than contemporary Australianoffice workers.

Activity data were recently collected from officeworkers in a major mining company using Acticalomni-axial accelerometers (Mini Mitter, Bend, OR,USA). Figure 1 shows the accelerometer ‘counts’ (ameasure of the amount and intensity of trunk move-ment) over a 24 h period on a work day from a singleworker. The data show the worker awoke and put theaccelerometer on their hip at around 06.15 hours andwent for a walk for about 25 min (steady state ofhigher intensity activity around 3000 counts). There isanother spike of activity around 08.00 hours associatedwith getting from their car to their office. Between08.00 and 13.20 hours, the worker was stationary attheir desk (counts close to zero) except for four briefmovements away from their desk (spikes around 600counts). From 13.30 to 14.30 hours, the worker wasmoving around, then sat again for most of the timeuntil leaving work around 18.00 hours. They were alittle active (sustained counts around 500) gettinghome and performing domestic duties prior to sittingand watching television from 19.45 to 20.45 hours.

Figure 2 shows a different worker day, with noearly morning walk but more regular movementaround the office during the day and over 1 h ofmoderate to vigorous activity (playing a ball sport) inthe evening. The low amount and intensity of move-ment at work (counts near to baseline most of the timewith occasional spikes to around 1500) contrasts withthe amount of movement during vigorous leisure

(counts frequently up to 3000). Figure 3 shows anon-work day, with a notable absence of prolongedsedentary (counts close to zero) periods except for 1 hof television viewing in the late evening. Together,these figures illustrate the sedentary nature of officework.

The higher proportion of workers employed inoccupations with low physical demands and thereduction in physical stresses within traditionallyphysically demanding industry sectors has led toworking life being more physically inactive for manyworkers. This physical inactivity may be detrimental totheir health as insufficient physical stress is known tohave short- and long-term detrimental health effects.

2. Physical inactivity is harmful

In an extreme example, the reduction in physical stresswhilst living in a micro-gravity environment is knownto result in reduced bone density, muscular strengthand endurance, impaired neuromuscular coordinationand cardiovascular fitness, increased orthostaticintolerance (tendency to faint) and a deterioration inmood and psychological state (Greenleaf et al. 1989a,Fitts et al. 2001). Over half Mir and InternationalSpace Station crew members lost more than 10% bonemineral density in at least one site (Shackelford et al.2004). Early Apollo astronauts experienced a 17–21%loss of aerobic capacity during space flights less than15 d long. Astronauts on a subsequent Skylab III flightof 59 d exercised for over 1 h per day to maintainaerobic capacity, yet still lost 20% thigh musclestrength. Insufficient physical stress can thereforeresult in a rapid deterioration of physical capacity.

In an example closer to home, prolonged bed rest isknown to reduce muscle strength by up to 0.5% perday and bone mineral density by up to 0.4% per day

Figure 1. Accelerometer counts for an office worker over a 24 h period including a work day.

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(Greenleaf et al. 1989b). Other musculoskeletal changesinclude increased bone re-absorption, increasedcalcium excretion and muscle atrophy (Shackelfordet al. 2004). The reduced cardiovascular load during 6weeks bed rest has been found to result in an 8%reduction in left ventricular mass (Perhonen et al. 2001).It has also been found that 15 d of bed rest decreaseswalking endurance time by 10%, peak oxygenconsumption by 14% and sprint speed by 16%(Watenpaugh et al. 2000). Bed rest also causes othermetabolic changes, such as increased sympatheticactivity and increased insulin resistance (Blanc et al.2000). These system changes result in functionalchanges, for example, Dupui et al. (1992) showed adecrease in gait performance and balance with 30 d ofhead-down bed rest. Fine and gross motor skills declinewithout practice (White et al. 2005). Again, the evidence

is clear that insufficient physical stress can lead to rapidand substantial loss of physical capacity anddisturbances in physiological adaptability.

At a local body part level, immobilisation (forexample, associated with management of a bonefracture) can result in muscular atrophy and reducedmuscle contractility and functional ability (Pathareet al. 2005). The majority of atrophy occurs in the first 2weeks of immobilisation, with 1–6% muscle strengthloss per day for the first week (Vanderborne et al. 1998).In a case study, Vandenborne et al. (1998) found a 20–32% loss of lower leg muscle cross-section area over 8weeks of immobilisation. This was associated with aneven larger (50%) loss of lower leg muscle strength anda 53% loss of central activation during voluntarycontractions, suggesting significant neurologicalchanges. Similarly, ankles immobilised for 6 weeks lost

Figure 2. Accelerometer counts for an office worker over a 24 h period including after work sport activity.

Figure 3. Accelerometer counts for an office worker over a 24 h period on a non-work day.

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around 128 dorsi-flexion range (Chesworth andVandervoort 1995). These local changes furtheremphasise that dramatic reductions in biomechanical,physiological and neurological capability can occurafter only short periods of inactivity.

On a longer timescale, chronic low levels ofphysical stresses are associated with musculoskeletal(osteoporosis), cardiovascular (hypertension, coronaryheart disease, ischaemic stroke), metabolic (obesity,insulin resistance, type II diabetes), mental (depres-sion) and other (some cancers) disorders (SurgeonGeneral 1996). In fact, in terms of contribution to illhealth, physical inactivity in Australia has been rankedsecond after tobacco (Stephenson et al. 2000). InCanada, it has been estimated that physical inactivityleads to direct and indirect costs amounting to 2.6% ofthe total healthcare expenditures; a burden similar tothat associated with obesity (Katzmarzyk and Janssen2004). An estimated 33% of deaths from coronaryartery disease, type II diabetes and colon cancercould be prevented by eliminating physical inactivity(Katzmarzyk et al. 2000).

Thus, there is now a widespread appreciation thatphysical activity is beneficial to health. Aspects ofphysical activity that are, for different reasons, likely tobe important for health include (as compared toinactivity) greater metabolism, more muscle activation,faster joint movements, increased demands for co-ordinated motor patterns and larger forces on thebones. Physical activity is prescribed therapy for manychronic diseases (Pedersen and Saltin 2006). Physicalactivity is also being promoted as an intervention toreduce the effects of ageing in terms of immunological(Senchina and Kohut 2007), motor (Wiesmann et al.2004) and cognitive (Angevaren et al. 2008) function. Ithas also been positively related to academic perfor-mance in children (Strong et al. 2005).

3. Is working life sufficiently inactive to have negative

health effects?

Whilst it is clear that pronounced physical inactivity isdetrimental to health and that working life is becomingless physically active, one may ask whether significantparts of working life have become so inactive that theyare now a threat to health.

For some effects of extreme inactivity, working lifemay indeed provide sufficient stimuli to avoid negativehealth effects. For example, to avoid loss of joint rangeof movement may only require movement to the end ofrange a few times each day, which is likely to occur innormal office tasks.

However, for several other effects of inactivity,modern office work is probably well below the requiredphysical stress thresholds to prevent loss of capacity.

Maintenance of muscle strength requires as few as sixrepetitions to fatigue repeated twice per week (Winettet al. 2003). To enhance bone mineral density at least10 maximal vertical jumps per day for 3 d per week areneeded (Kato et al. 2006). To maintain cardiovascularfitness, 20 min periods of moderate intensity (55–90%of the age-predicted heart rate maximum) three tofive times per week (American College of SportsMedicine 1998) or 3-min periods of high intensity(70–80% of the age-predicted heart rate maximum)twice per week (Winett et al. 2003) are required. Toavoid diseases associated with chronic inactivity, about30 min per day of moderately vigorous activity isrequired and, to maintain healthy weight, about60 min of moderate intensity activity is required eachday (Wing and Hill 2001, Saris et al. 2003). These levelsof muscle loading, bone loading and metabolicintensity and dose are unlikely in modern office work.

Insufficient physical activity at work should also beviewed in the context of daily living that has alsobecome less physically demanding. Transport to andfrom work has become more sedentary. For example,in the USA travelling to work by car increased from67% in 1960 to 88% in 2000, with a commensuratedecline in walking or public transport travel(Brownson et al. 2005). Figure 4 shows the decline inthe proportion of people in Japan participating inwalking or light physical exercise. Physical workloadsassociated with domestic duties are now reduced with‘labour-saving’ technology, such as machines forwashing clothes and dishes. This has resulted in adecline in the time that US women spend doinghousehold work, from around 28 h per week in 1965 to15 h per week in 1995 (Brownson et al. 2005), seeFigure 5. Associated with this has been an increase inthe time spent watching television. Average dailyviewing by US residents has increased from 4.6 h in1950 to over 7 h in 2000 (Brownson et al. 2005), asshown in Figure 6. Recently, Internet use has becomea popular sedentary pastime, as shown in Figure 4.

Figure 4. Participation in walking and Internet use in Japan(data from www.stat.go.jp/english).

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The energy expenditure, heart rate, muscle activity andmovements during popular leisure activities such aswatching television and playing electronic games aresimilar to resting levels (Straker and Abbott 2007).

In summary, it is believed that, for many workersin affluent information-based societies, work hasbecome sufficiently inactive to have negative healtheffects, which are not compensated for by activity intransport, domestic chores or leisure. This is supportedby the recent report on ‘emerging physical risks’, putforward by a panel of work environment expertswithin the framework of the European Agency forSafety and Health at Work (2005), which noted thatinactivity is probably one of the major threats to health

in future working life. This is a dramatically changedscenario compared to the classic ergonomics view onoccupational health as being an issue of reducingexposures to high loads.

4. Traditional physical ergonomics paradigm – ‘less is

better’

In the twentieth century, ergonomics, with a strongbasis in human engineering (Dempsey and Mathiassen2006), developed a paradigm where the main approachwhen pursuing optimal work was to decreaseexposures so as to protect workers from metabolicoverload, fatigue or biomechanical strain; i.e. a ‘less isbetter’ principle. Thresholds were developed andsubsequently revised to operationalise this approach(Westgaard and Winkel 1996). For whole bodymetabolic loads, 50% of the maximal oxygen uptakewas suggested in 1960 by Astrand as the upper limit foran 8-h daily average. This recommendation was laterreduced to 40% (Astrand 1967), 30–35% (Jørgensen1985) and 30% (Frings-Dresen et al. 1995); the latterthreshold corresponding to the suggested threshold of30% of the relative heart rate (Ilmarinen 1992).

In the latter part of the twentieth century, the focusshifted from whole body loads to local muscle loads. In1973, Rohmert considered forces below 15% ofmaximal to be safe (Rohmert 1973), mainly from ametabolic point of view. On the basis of experimentson muscle fatigue, Jonsson (1978) suggested that atleast 10% of the working day should be spent withloads less than 5% maximal activity. This was laterreduced, with Aaras (1987) claiming that 1% would bea reasonable limit for the 10th percentile andWestgaard (1988) suggesting that rest breaks, i.e.periods of zero load, were needed to avoidmusculoskeletal problems.

The early development of ergonomics as a scientificdiscipline occurred in Europe, when workers werecommonly exposed to high physical workloaddemands (high energy expenditure, high heart ratesand high forces), for example, in forestry (Rabinbach1992). The development of an ergonomics paradigmwhere ‘less is better’ was appropriate where work wasboth biomechanically and physiologically verydemanding. In some countries and in some jobs, it istherefore still appropriate for ergonomics to focus onrisk reduction by physical stress/exposure reduction inhigh exposure situations.

5. Rising awareness of need to change ‘less is better’

paradigm

Some opposition has, however, been raised to the ‘lessis better’ paradigm. In the early 1980s, Winkel (1981)

Figure 5. Weekly paid and household work in USA (datafrom Brownson et al. 2005).

Figure 6. Daily television viewing in USA (data fromBrownson et al. 2005).

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and Arendt (1983) suggested that more variationrather than even lower loads would be anappropriate initiative for reducing musculoskeletalproblems in sedentary jobs with an already low levelof physical workload. Later papers proposed that a U-shaped relationship between exposure levels and riskfor musculoskeletal disorders would apply to severalgeneric risk factors (Winkel and Westgaard 1992), thatis, too small and too large exposures would both be aproblem for health. The notion of too little exposurebeing a factor of concern has been pursued in studiesinvestigating the idea that ‘active breaks’, includingmore vigorous activities than normal – sedentary –work, may be more recuperative than rest (Sundelinand Hagberg 1989, Mathiassen and Winkel 1996,Henning et al. 1997, van den Heuvel et al. 2003).

Other researchers have also suggested increasingthe physical stresses of workers. For example, dynamicseating has been recommended by Stranden (2000) toincrease leg movements, and thus decrease leg swellingassociated with prolonged sitting, and by O’Sullivanet al. (2006) to enhance spinal motion. In a moreradical example, Edelson and Danoffz (1989) recom-mended treadmill walking while working with acomputer and this has recently been widely promotedas a mechanism to avoid obesity related to inactivity(Levine and Miller 2007). Evidence in these and relatedstudies that the desired outcome was achieved suggeststhat beneficial effects of increased activity can beobserved on short-term responses related to well-being.Long-term results are rarely investigated.

Most of these initiatives for increased physicalactivity at work have been developed by ergonomistsin order to improve well-being and, possibly, health.Thus, their effects on productivity have not been amajor concern, even if addressed in some cases(Galinsky et al. 2000, Dababneh et al. 2001) and lossin productivity can, indeed, be considered a necessaryevil associated with attempts to improve health by, forexample, extended allowances for rest breaks. Inter-estingly, however, the basic idea of finding an optimal –rather than a minimal – level of physical activity thatwill secure physical health and well-being is in keepingwith basic production engineering endeavours toidentify an optimal working schedule that will lead tothe maximal work output across an extended period oftime (Bechtold et al. 1984, Dempsey and Mathiassen2006). Thus, ergonomists and engineers may find acommon interest in identifying appropriate ways ofincreasing physical activity in sedentary jobs (Wellset al. 2007).

Many occupational health and safety authoritiesrecognise that risks to musculoskeletal health exist notonly in high physical stress jobs, such as frequentlifting, but also in monotonous, repetitive, low physical

stress jobs (Swedish Work Environment Authority1998, Australian Safety and Compensation Council2007). The guidance given in how to avoid risks in thistype of job includes rest breaks, in line with the ‘less isbetter’ paradigm. However, the guidance often alsoincludes other initiatives, such as job rotation and jobdiversification. Whilst the basic purpose is to createexposure variation for the muscles and joints(Mathiassen 2006) and not per se to introduce morephysical stress, this does acknowledge that ‘more canbe better’ in sedentary jobs.

The rising awareness that inactivity at work is anissue has not yet generally developed into a basic viewthat employers have a responsibility for not givingpeople too little physical stress, like they havetraditionally accepted responsibility for notoverloading workers. Still, some recent events suggestthat this can change.

In 2006, Norway was the first country, to thepresent authors’ knowledge, to implement legislationwith the purpose to: ‘‘secure a work environment thatgives a basis for a health promoting and meaningfulwork situation’’ (x1–1) and more explicitly: ‘Theemployer must, in connection with the systematicmanagement of health, environment and safety,consider initiatives to promote physical activitiesamong the employees’ (x3–4) (Norwegian Parliament2006; author’s translations). In other countries, thereare also signs that this realisation is dawning. Forexample, the Dutch national organisation, TNO, haslaunched a recommendation for ‘sufficient physicalactivity at work’ (Commissaris et al. 2006). However,no systematic evaluation is yet available on how theseinitiatives are received and implemented in working life(B. Veiersted, personal communication; D.Commissaris, personal communication), nor whetherthey do promote long-term health.

6. Work is a health enhancement opportunity

In the context of the worker’s musculoskeletal health,the responsibility of companies has traditionally beenrestricted to risk exposure during working hours. Thishas, however, not been the case for several other healthissues. For example, many companies support smokingcessation and alcohol awareness programmes, despitethe health risks being mainly non-work-related. Thus,companies have demonstrated a willingness to take a‘whole of life’ approach to worker health. Such anapproach is also sensible for physical activity, as bothwork and leisure become more sedentary, and it wouldinvolve a ‘more can be better’ view on physical workload. Designing work to improve physical healthwould be a means for companies to create attractivejobs (in a time of workforce shortages), as well as an

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opportunity to attract customers by claiming a healthyand well-taken-care-of workforce. Some companieshave realised that increased physical load at work canbe a way of both increasing the performance of staffand creating attractive jobs for people interested inkeeping healthy. One example is a Swedish call centre,which, realising that no work tasks were available thatwould offer increased physical stress, implementedphysical training at an in-house gym as a mandatorywork task (Mathiassen et al. 2007). According toreports from the company, the change not only led togreater employee satisfaction and less sick leave, butalso to a change in the demographic profile of newemployees towards more young people.

Better health is an obvious interest to society andauthorities in affluent countries are well aware of thenegative health effects associated with citizens beingless physically active. However, campaigns and in-itiatives for increased activity among adults havealmost exclusively been directed towards leisure time.It is argued here that authorities also need to adopt anew perspective, supporting employers to create workthat not only protects workers from too much physicalstress, but also from too little. So far, authorities havenot fully realised the potential to improve public healththrough increased physical loads at the workplace.

7. Physical work can be designed to not only avoid ill

health but promote good health

Designing work to have positive health benefits, ratherthan just designing work to avoid ill health, is a newconcept for physical ergonomics, but it is already a long-established concept in psychosocial ergonomics. Forexample,Herzberg (1966) identifiedwork characteristicsto minimise job dissatisfaction (‘hygiene’ factors) anddifferent work characteristics that would promote jobsatisfaction (‘motivation’ factors). More recent workhas argued that psychosocial stress can have bothnegative and positive effects. In a review, Edwards andCooper (1988) note that positive stress (eustress), such asjob satisfaction, positive life events and laughter, isrelated to beneficial physiological effects and betterhealth. Physical ergonomics to date has only focused on‘negative’ hygiene factors and not on the ‘positive’motivation factors, but there are no reasons not to adoptthe psychosocial tradition that work should be ofpositive value and result in improved physical capacityand well-being rather than just avoid ill health.

The prescription of increased physical stress iscurrently increasing, though not in the occupationaldomain. For example, up to one-third of adults receivecounselling about increasing their physical activity inthe USA now and health professionals are beingencouraged to further promote increased physical

activity (Physical Activity Taskforce 2001, Mansonet al. 2004). Some companies do, indeed, try to increasethe physical activity of their workforce, yet outside ofwork tasks, for example, by the provision of exercisefacilities at the workplace or sponsoring gymmembership for employees (Goetzel and Ozminkowski2008). However, the work itself is not being designedto create physical eustress; that is, to be physicallybeneficial. The comparative situation in a psychosocialdomain would be allowing a worker who has a boring,unfulfilling job with no social contact to go three timesper week to an interesting, fun and socially rewardingactivity outside the workplace to compensate for theunsatisfying work.

8. How to design work to be physically beneficial?

It has been argued that modern office workers havebecome sufficiently inactive to put their health at risk.It has also been argued that if work could be designedaccording to a ‘more can be better’ principle to provideappropriate physical stresses it would be to the benefit(including financial) of workers, employers andsociety. The challenge to physical ergonomics then is tooperationalise the new paradigm of ‘more can bebetter’ by providing guidance on how to design workto be physically beneficial. Work designed to bebeneficial to health may look very different to workdesigned simply to avoid harm. Therefore, newconcepts for designing work tasks or work stations willbe needed.

Work designed to promote good physical healthneeds to include large exposure amplitudesoccasionally, for local muscles as well as for joints andthe general metabolism. In office work, this aim for‘healthy work’ fits with the general acceptance ofincreasing exposure variation; however, with theadditional requirement that the added loads must besufficiently vigorous to trigger a positive adaptation ofthe body, that is, a training effect. Thus, one may needto return some activities, putting high demands onneuromuscular and cardiovascular systems, whichprior ergonomists and engineers took out of people’swork. Changes to work could be at an equipment level(e.g. sit/stand tables, moving the printer to the secondfloor), task level (e.g. including physical work as awork task, mixing available ‘heavy’ tasks among theemployees) or organisational level (e.g. physicalactivity campaigns, organisational culture changes).

Whilst these changes in work have a clear logicalbasis, they may re-introduce problems that are wellknown to traditional ergonomics and epidemiology.As with any strength and endurance training, theadded activities need to be well designed to maximisepositive effects and minimise the risk of injury. Even

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for successfully designed work with occasional highloads, a trade-off will need to be accepted betweenshort-term risks and long-term risk. There is already aprecedent for this, where the risk of an acute sprainfrom exercise at an employer-supported gym isbalanced against the greater risk reduction frombetter worker physical fitness.

Careful consideration of the physical workloadneeds of sedentary workers will generate more provo-cative examples of what the ‘new work’ may look like.For example, the need for practice to avoid a decrease inmotor skills (White et al. 2005) may suggest that the newwork should require workers to do unusual, awkwardand strange motor-challenging tasks to stimulate themotor control system. Providing challenging tasks is aproven intervention currently used to improve themotorcapacity of children and the elderly with poor motorcontrol (Peters and Wright 1999, Toulotte et al. 2003).By requiring the development of motor strategies forunexpected situations, the capacity of the worker’smotor system could be improved to give them greaterflexibility for future tasks.

The new work may have positive or negative effectson short-term productivity; for instance, if more‘unproductive’ walking is introduced during workinghours. Any short-term production deficits are, however,likely to be less than those associated with initiativessuch as allowing workers some hours of exercise everyweek at a gym, during which no productive work is donewhatsoever. Positive long-term effects are likely toinclude lower costs for sick leave, a more stable anddedicated workforce, more attractive jobs when recruit-ing new workforce and public relations advantages.Evidence also suggests sufficient physical activity canactually be associated with better work quality andoverall job performance. For example, Pronk et al.(2004) collected self-reports of physical activity andwork performance quality and quantity from 683workers in the USA. They reported significant improve-ments in work quality and quantity with increasedmoderate physical activity (odds ratios 1.06 and 1.05respectively).

The approach of designing work that can improvehealth presents ergonomists with a number of chal-lenges. The amplitude, duration and the pattern ofhigher loads will need to be designed to provide aneffective ‘prescription’ as it has been found that simplya high amplitude of physical workload may notnecessarily lead to improved metabolic capacity(Ilmarinen 1992). A clearer understanding of themechanisms linking physical activity patterns andhealth are required, including methods for operatio-nalising key exposure elements. Thus, ‘healthy’ pat-terns of work must be determined in terms of exposurelevels, frequencies and durations, in the context of the

requirements and conditions in each specificoccupation and company. In addition, the effects onperformance and productivity need to be understoodand managed to optimise trade-offs between health,well-being and performance. Procedures must bedeveloped and tested of how to successfully implantthe ideas and programmes of ‘healthy work’ in acompany and among the workers at a company.Systems must be established that can help workers andcompanies to monitor and evaluate physical activity atthe workplace.

9. Conclusion

One of the principle aims of ergonomics is to protectworker’s health. While the traditional physicalergonomics paradigm has been to realise this aim byeliminating high physical workloads, lack of physicalactivity is now a major health threat for many workers.This calls for a changed view on ergonomics goals andtools. Work provides an opportunity for instigatingphysical loads that can aid in protecting against ill healthand even have the aim of improving physical capacityand health.

Thus, the new paradigm for physical ergonomicsrequires work to be designed not only to avoid illhealth, but even to provide sufficient dose andvariation of physical stress to have positive healthbenefits, akin to exercise programmes.

This new paradigm not only challenges theperspective that ergonomists should take when helpingemployers and employees, but also challenges them todevelop adequate theory and measurement concepts toevaluate work/exercise prescription. Such initiativeswill probably require ergonomics to accept a trade-offin terms of a slightly increased occurrence of some‘classical’ musculoskeletal disorders, for instance, lowback pain, in return for decreased occurrence of thenew health risks associated with insufficient physicalloads.

Acknowledgements

The authors would like to acknowledge the assistance ofJemma Coleman (literature searching), Sharon Parry(literature and data collection) and David Todd (access tooffice workers for data collection).

References

Aaras, A., 1987. Postural load and development ofmusculoskeletal illness. Scandinavian Journal ofRehabilitation Medicine, 19, 1–35.

American College of Sports Medicine, 1998. Position standon the recommended quantity and quality of exercise fordeveloping and maintaining cardiorespiratory andmuscular fitness, and flexibility in adults. Medicine andScience in Sports and Exercise, 30 (6), 975–991.

1222 L. Straker and S.E. Mathiassen

Dow

nloa

ded

by [

Uni

vers

ity o

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asm

ania

] at

04:

27 0

1 Se

ptem

ber

2014

Angevaren, M., et al., 2008. Physical activity and enhancedfitness to improve cognitive function in older peoplewithout known cognitive impairment. Cochrane Data-base of Systematic Reviews, (2), CD005381.

Arendt, R., 1983. Work posture and musculoskeletalproblems of video display terminal operators – reviewand reappraisal. American Industrial Hygiene AssociationJournal, 44, 437–446.

Arvidsson, I., et al., 2006. Changes in physical workload withimplementation of mouse-based information technologyin air traffic control. International Journal of IndustrialErgonomics, 36, 613–622.

Astrand, I., 1967. Degree of strain during building work asrelated to individual aerobic work capacity. Ergonomics,10, 293–303.

Attebrant, M., et al., 1997. Shoulder-arm muscle loadand performance during control operation in forestrymachines: Effects of changing to a new arm rest, leverand boom control system. Applied Ergonomics, 28 (2),85–97.

Australian Bureau of Statistics, 2003. Measures of a knowl-edge-based economy and society, Australia: Proportion ofbusinesses with computers, web sites and Internet access bybusiness size [online]. Available from: http://www.abs.gov.au/Ausstats/abs@.nsf/0/C642F3B7DFE50B7ECA256D97002C8647?Open [Accessed 14 May 2005].

Australian Safety and Compensation Council, 2007. NationalCode of Practice for the Prevention of MusculoskeletalDisorders from Performing Manual Tasks at Work.Canberra, Australia: Australian Safety and Compensa-tion Council.

Axelsson, S. and Ponten, B., 1990. New ergonomic problemsin mechanized logging operations. International Journalof Industrial Ergonomics, 5 (3), 267–273.

Bechtold, S.E., Janaro, R.E., and DeWitt, L.S., 1984. Maxi-mization of labor productivity through optimal rest-break schedules. Management Science, 30, 1442–1458.

Blanc, S., et al., 2000. Fuel homeostasis during physicalinactivity induced by bed rest. The Journal of ClinicalEndocrinology and Metabolism, 85 (6), 2223–2233.

Blangsted, A.K., Hansen, K., and Jensen, C., 2003. Muscleactivity during computer-based office work in relation toself-reported job demands and gender. European Journalof Applied Physiology, 89, 352–358.

Brownson, R.C., Boehmer, T.K., and Luke, D.A., 2005.Declining rates of physical activity in the United States.Annual Review of Public Health, 26, 421–443.

Bystrom, J.U., et al., 2002. Physical workload on neck andupper limb using two CAD applications. AppliedErgonomics, 33, 63–74.

Chesworth, B.M. and Vandervoort, A.A., 1995. Comparisonof passive stiffness variables and range of motion inuninvolved and involved ankle joints of patients follow-ing ankle fractures. Physical Therapy, 75 (4), 253–261.

Commissaris, D.A., et al., 2006. Recommendations for suffi-cient physical activity at work. In: Meeting diversity inergonomics. Proceedings of the International ErgonomicsAssociation 2006 conference. Maastricht: Elsevier. [CD-ROM].

Dababneh, A.J., Swanson, N., and Shell, R.L., 2001. Impactof added rest breaks on the productivity and well being ofworkers. Ergonomics, 44, 164–174.

Dempsey, P.G. and Mathiassen, S.E., 2006. On the evolutionof task-based analysis of manual materials handling, andits applicability in contemporary ergonomics. AppliedErgonomics, 37, 33–43.

Dupui, P., et al., 1992. Balance and gait analysis after 30days-6 degrees bed rest: influence of lower-body negativepressure sessions. Aviation and Space EnvironmentalMedicine, 63, 1004–1010.

Edelson, N. and Danoffz, J., 1989. Walking on an electrictreadmill while performing VDT office work. SIGCHIBulletin, 21 (1), 72–77.

Edwards, J.R. and Cooper, C.L., 1988. The impacts ofpositive psychological states on physical health: A reviewand theoretical framework. Social Science & Medicine,27 (12), 1447–1459.

Egger, G.J., Vogels, N., and Westerterp, K.R., 2001.Estimating historical changes in physical activity levels.Medical Journal of Australia, 175, 635–636.

European Agency for Health and Safety at Work, 2005.Expert forecast on emerging physical risks related tooccupational safety and health. Luxembourg: Office forOfficial Publications of the European Communities.

Fitts, R.H., Riley, D.R., and Widrick, J.J., 2001. Functionaland structural adaptations of skeletal muscle tomicrogravity. Journal of Experimental Biology, 204 (18),3201–3208.

Frings-Dresen, M.H.W., et al., 1995. Guidelines for energeticload in three methods of refuse collecting. Ergonomics,38, 2068–2077.

Galinsky, T.L., et al., 2000. A field study of supplementaryrest breaks for data-entry operators. Ergonomics, 43,622–638.

Goetzel, R.Z. and Ozminkowski, R.J., 2008. The health andcost benefits of work site health-promotion programs.Annual Reviews of Public Health, 29, 303–323.

Greenleaf, J., et al., 1989a. Exercise-training protocols forastronauts in microgravity. Journal of AppliedPhysiology, 67 (6), 2191–2204.

Greenleaf, J., et al., 1989b. Work capacity during 30-days ofbed rest with isotonic and isokinetic exercise training.Journal of Applied Physiology, 67, 1820–1826.

Henning, R.A., et al., 1997. Frequent short rest breaks fromcomputer work: effects on productivity and well-being attwo field sites. Ergonomics, 40, 78–91.

Herzberg, F.I., 1966.Work and the nature of man. New York:World Publishing Corp.

Hjortskov, N., et al., 2004. The effect of mental stress onheart rate variability and blood pressure duringcomputer work. European Journal of Applied Physiology,92 (1–2), 84–89.

Ilmarinen, J., 1992. Job design for the aged with regard todecline in their maximal aerobic capacity: Part I.Guidelines for the practitioner. International Journal ofIndustrial Ergonomics, 10, 53–63.

Jonsson, B., 1978. Kinesiology – with special reference toelectromyographic kinesiology. In: W. Cobb and H. VanDuijn, eds. Contemporary clinical neurophysiology.Amsterdam: Elsevier, 417–428.

Jorgensen, K., 1985. Permissible loads based on energyexpenditure measurements. Ergonomics, 28, 365–369.

Kato, T., et al., 2006. Effect of low-repetition jump trainingon bone mineral density in young women. Journal ofApplied Physiology, 100 (3), 839–843.

Katzmarzyk, P., Gledhill, N., and Shepard, R., 2000. Theeconomic burden of physical inactivity in Canada.CanadianMedicalAssociation Journal, 163 (11), 1435–1440.

Katzmarzyk, P.T. and Janssen, I., 2004. The economic costsassociated with physical inactivity and obesity inCanada: an update. Canadian Journal of AppliedPhysiology, 29, 90–115.

Ergonomics 1223

Dow

nloa

ded

by [

Uni

vers

ity o

f T

asm

ania

] at

04:

27 0

1 Se

ptem

ber

2014

Klucharev, V., et al., 2000. Monitor jitter and human-computer interaction. Displays, 21 (5), 173–177.

Levine, J.A. and Miller, J.M., 2007. The energy expenditureof using a ‘walk-and-work’ desk for office workers withobesity. British Journal of Sports Medicine, 41 (9), 558–561.

Manson, J.E., et al., 2004. The escalating pandemics ofobesity and sedentary lifestyle – A call to action forclinicians. Archives of Internal Medicine, 164 (3), 249–258.

Mathiassen, S.E., 2006. Diversity and variation in biome-chanical exposure: what is it, and why would we like toknow? Applied Ergonomics, 37, 419–427.

Mathiassen, S.E. and Winkel, J., 1996. Physiologic compar-ison of three interventions in light assembly work:reduced work pace, increased break allowance andshortened working days. International Archives of Occu-pational and Environmental Health, 68, 94–108.

Mathiassen, S.E., et al., 2003. Efficient one-day sampling ofmechanical job exposure data – a study based on uppertrapezius activity in cleaners and office workers. Amer-ican Industrial Hygiene Association Journal, 64, 196–211.

Mathiassen, S.E., et al., 2007. Ergonomi - for ett gott arbete[Ergonomics – for good work]. In Swedish. Stockholm:Prevent.

Norwegian Parliament, 2006. Lov om arbeidsmiljø, arbeidstidog stillingsvern mv [Act on work environment, workinghours, security of employment etc]. In Norwegian.Lovdata, Oslo. Available from: http://www.lovdata.no/all/nl-20050617–062.html [Accessed 24 May 2008].

Official Statistics of Sweden, 2005. The Work Environment2005. Statistiska meddelanden (Statistics reports) AM68SM0601. [In Swedish, summary in English]. Stockholm:Swedish Work Environment Authority and StatisticsSweden.

O’Sullivan, P., et al., 2006. Lumbopelvic kinematics andtrunk muscle activity during sitting on stable andunstable surfaces. Journal of Orthopaedic Sports PhysicalTherapy, 36 (1), 19–25.

Pathare, N., et al., 2005. Changes in inorganic phosphate andforce production in human skeletal muscle after castimmobilization. Journal of Applied Physiology, 98 (1),307–314.

Pedersen, B.K. and Saltin, B., 2006. Evidence for prescribingexercise as therapy in chronic disease. ScandinavianJournal of Medicine and Science in Sports, 16 (Suppl. 1),3–63.

Perhonen, M.A., et al., 2001. Cardiac atrophy after bed restand spaceflight. Journal of Applied Physiology, 91 (2),645–653.

Peters, J. and Wright, A., 1999. Development and evaluationof a group physical activity programme for children withdevelopmental co-ordination disorder: An interdisciplin-ary approach. Physiotherapy Theory and Practice, 15,203–216.

Physical Activity Taskforce, 2001. Getting Western Austra-lians more active – A strategic direction report from thePremier’s physical activity taskforce. Perth, WA: WesternAustralian Government.

Pronk, N., et al., 2004. The association between workperformance, cardiorespiratory fitness and obesity. Jour-nal of Occupational and Environmental Medicine, 46 (1),19–25.

Rabinbach, A., 1992. The human motor: Energy, fatigue, andthe origins of modernity. Berkeley, CA: University ofCalifornia Press.

Rohmert, W., 1973. Problems in determining rest allowances.Part 2: Determining rest allowances in different humantasks. Applied Ergonomics, 4, 158–162.

Saris, W.H.M., et al., 2003. How much physical activity isenough to prevent unhealthy weight gain? Outcome ofthe IASO 1st Stock Conference and consensus statement.Obesity Reviews, 4 (2), 101–114.

Schofield, G., Badlands, H., and Oliver, M., 2005.Objectively-measured physical activity in New Zealandworkers. Journal of Science Medicine and Sport, 8 (2),143–151.

Senchina, D.S. and Kohut, M.L., 2007. Immunologicaloutcomes of exercise in older adults. ClinicalInterventions in Aging, 2 (1), 3–16.

Shackelford, L.C., et al., 2004. Resistance exercise as acountermeasure to disuse-induced bone loss. Journal ofApplied Physiology, 97, 119–129.

Shemwetta, D., Ole-Meiludie, R., and Silayo, D., 2002. Thephysical workload of employees in logging and forestindustries. In: Wood for Africa 2002 Forest EngineeringConference, 2–3 July 2002, South Africa,Pietermaritzburg.

Statistics Sweden, 2005. Trends and Forecasts 2005;population, education and labour market in Sweden –outlook to year 2020. [In Swedish, summary in English].Stockholm: Statistics Sweden.

Stephenson, J., et al., 2000. The costs of illness attributable tophysical inactivity in Australia: A preliminary study.Canberra, Australia: Population Heath Division.

Straker, L. and Abbott, R., 2007. Effect of screen basedmedia on energy expenditure and heart rate in 9–12 yearold children. Pediatric Exercise Science, 19, 459–471.

Stranden, E., 2000. Dynamic leg volume changes when sittingin a locked and free-floating tilt office chair. Ergonomics,43 (3), 421–433.

Strong, W.B., et al., 2005. Evidence based physical activityfor school-age youth. The Journal of Pediatrics, 146 (6),732–737.

Sundelin, G. and Hagberg, M., 1989. The effects of differentpause types on neck and shoulder EMG activity duringVDU work. Ergonomics, 32, 527–537.

Surgeon General, 1996. Physical activity and health: A reportof the Surgeon General. Atlanta, GA: US Department ofHealth and Human Services.

Swedish Work Environment Authority, 1998.Belastningsergonomi [Ergonomics for the prevention ofmusculoskeletal disorders]. Ordinance 1998:1. [InSwedish]. Stockholm: Swedish Work EnvironmentAuthority.

Toulotte, C., et al., 2003. Effects of physical training on thephysical capacity of frail, demented patients with ahistory of falling: a randomised controlled trial. Ageing,32 (1), 67–73.

van den Heuvel, S.G., de Looze, M.P., and Hildebrandt,V.H., 2003. Effects of software programs stimulatingregular breaks and exercises on work-related neck andupper-limb disorders. Scandinavian Journal of WorkEnvironment and Health, 29, 106–116.

Vandenborne, K., et al., 1998. Longitudinal study ofskeletal muscle adaptations during immobilizationand rehabilitation. Muscle and Nerve, 21 (8),1006–1012.

Watenpaugh, D.E., et al., 2000. Supine lower bodynegative pressure exercise during bed rest maintainsupright exercise capacity. Journal of Applied Physiology,89 (1), 218–227.

1224 L. Straker and S.E. Mathiassen

Dow

nloa

ded

by [

Uni

vers

ity o

f T

asm

ania

] at

04:

27 0

1 Se

ptem

ber

2014

Wells, R.H., et al., 2007. Time – a key issue formusculoskeletal health and manufacturing. AppliedErgonomics, 38, 733–744.

Westgaard, R.H., 1988. Measurement and evaluation ofpostural load in occupational work situations. EuropeanJournal of Applied Physiology, 57, 291–304.

Westgaard, R.H. and Winkel, J., 1996. Guidelines foroccupational musculoskeletal load as a basis for inter-vention: A critical review. Applied Ergonomics, 27, 79–88.

White, F., Hayes B., and Livesey, D., 2005. Developmentalpsychology: From infancy to adulthood. Frenches Forest,Australia: Pearson.

Wiesmann, U., et al., 2004. Motorische Handlungskompe-tenz und Lebensqualitat alterer aktiver Menschen.[Motor capacity and quality of life among active, agedsubjects]. Zeitschrift fur Gerontologie und Geriatrie, 37(5), 377–386.

Winett, R., et al., 2003. Effects of low volume resistance andcardiovascular training on strength and aerobiccapacity in unfit men and women: A demonstration ofa threshold model. Journal of Behavioral Medicine, 26 (3),183–195.

Wing, R.R. and Hill, J.O., 2001. Successful weight lossmaintenance. Annual Review of Nutrition, 21 (1), 323–341.

Winkel, J.. Swelling of the lower leg in sedentary work – apilot study. Journal of Human Ergology, 10, 139–149.

Winkel, J. and Westgaard, R., 1992. Occupational andindividual risk factors for shoulder-neck complaints: PartII – the scientific basis (literature review) for the guide.International Journal of Industrial Ergonomics, 10, 85–104.

Won, E.J., et al., 2009. Upper extremity biomechanics incomputer tasks differ by gender. Journal ofElectromyography and Kinesiology, 19, 428–436.

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