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Standing/SittingWorking in a Standing PositionsCan working in a standing position cause health problems?Standing is a natural human posture and by itself poses no particular health hazard. However, working in a standing position on a regular basis can cause sore feet, swelling of the legs, varicose veins, general muscular fatigue, low back pain, stiffness in the neck and shoulders, and other health problems. These are common complaints among sales people, machine operators, assembly-line workers and others whose jobs require prolonged standing.How can working in a standing position be a problem?A person's body is affected by the arrangement of the work area and by the tasks that he or she does while standing. The layout of the workstation, the tools, and the placement of keys, controls and displays that the worker needs to operate or observe will determine, and as rule, limit the body positions that the worker can assume while standing. As a result, the worker has fewer body positions to choose from, and the positions themselves are more rigid. This gives the worker less freedom to move around and to rest working muscles. This lack of flexibility in choosing body positions contributes to health problems.These conditions commonly occur where the job is designed without considering the characteristics of the human body. When job design ignores the basic needs of the human body (and individual workers), work can cause discomfort in the short term and can eventually lead to severe and chronic health problems.What are some of the health hazards?Keeping the body in an upright position requires considerable muscular effort that is particularly unhealthy even while standing motionless. It effectively reduces the blood supply to the loaded muscles. Insufficient blood flow accelerates the onset of fatigue and causes pain in the muscles of the legs, back and neck (these are the muscles used to maintain an upright position).The worker suffers not only muscular strain but other discomforts also. Prolonged and frequent standing, without some relief by walking, causes blood to pool in the legs and feet. When standing occurs continually over prolonged periods, it can result in inflammation of the veins. This inflammation may progress over time to chronic and painful varicose veins. Excessive standing also causes the joints in the spine, hips, knees and feet to become temporarily immobilized or locked. This immobility can later lead to rheumatic diseases due to degenerative damage to the tendons and ligaments (the structures that bind muscles to bones).What are some recommendations for improving workplace design?In a well-designed workplace, the worker has the opportunity to choose from among a variety of well-balanced working positions and to change between them frequently.Working tables and benches should be adjustable. Being able to adjust the working height is particularly important to match the workstation to the worker's individual body size and to the worker's particular task. Adjustability ensures that the worker has an opportunity to carry out work in well-balanced body positions. If the workstation cannot be adjusted, platforms to raise the shorter worker or pedestals on top of workstations for the tall worker should be considered.Organization of the work space is another important aspect. There should be enough room to move around and to change body position. Providing built-in foot rails or portable footrests allows the worker to shift body weight from one leg to the other. Elbow supports for precision work help reduce tension in the upper arms and neck. Controls and tools should be positioned so the worker can reach them easily and without twisting or bending.Where it is possible, a seat should be provided so that the worker can do the job either sitting or standing. The seat must place the worker at a height that suits the type of work being done. For work that requires standing only, a seat should be provided in any case to allow the worker to sit occasionally. Seats at the workplace expand the variety of possible body positions and give the worker more flexibility.The benefits from greater flexibility and a variety of body positions are twofold. The number of muscles involved in the work is increased which equalizes the distribution of loads on different parts of the body. Thus, there is less strain on the individual muscles and joints used to maintain the upright position. Changing body positions also improves blood supply to the working muscles. Both effects contribute to the reduction of overall fatigue.Quality of footwear and type of flooring materials are also major factors contributing to standing comfort. How can job design reduce the ill effects of working in a standing position?The basic principles of good job design for standing work are: Change working positions frequently so that working in one position is of a reasonably short duration. Avoid extreme bending, stretching and twisting. Pace work appropriately. Allow workers suitable rest periods to relax; exercises may also help. Provide instruction on proper work practices and the use of rest breaks. Allow workers an adjustment period when they return to work after an absence for vacation or illness so they can gradually return to a regular work pace.

How can work practices reduce the ill effects of working in a standing position?A well-designed workplace combined with a well-designed job makes it possible to work in a balanced position without unnecessary strain on the body. Although the actual performance of the task depends on the worker (including how the worker stands, moves or lifts), work practices can make the job either safer or more hazardous. Proper training shapes individual work habits and should be provided by a supervisor who encourages the worker to use the skills they have learned.It is important that the worker be informed of health hazards in the workplace. In fact it is a legal requirement. The worker needs to understand which body movements and positions contribute to discomfort and that the conditions causing mild discomfort can lead to chronic injury in the long term. Worker training should also contain information on how to adjust specific workplace layouts to the individual's advantage to reduce or eliminate health hazards.The worker should be aware that rest periods are important elements of the work. Rest periods should be used to relax when muscles are tired, to move around when muscles are stiff, to walk when work restricts the worker's ability to change postures or positions, and so on. The worker should also be encouraged to report discomforts experienced during work. It may result in correcting working conditions.All these elements -- training and supervision, coupled with active worker input -- can result in sound work practices. It must be remembered that a well-designed job and workplace are essential to healthy and safe work. Without these, good work practices cannot be effective.What is an example of a workstation designed for a standing worker?Workplace design should fit the variety of workers' shapes and sizes and provide support for the completion of different tasks.Different tasks require different work surface heights: Precision work, such as writing or electronic assembly - 5 cm above elbow height; elbow support is needed. Light work, such as assembly-line or mechanical jobs - about 5-10 cm below elbow height. Heavy work, demanding downward forces - from 20-40 cm below elbow height.

What can workers do to reduce the discomfort of working in a standing position? Adjust the height of the work according to body dimensions, using elbow height as a guide. Organize your work so that the usual operations are done within easy reach.

Always face the object of work. Keep body close to the work. Adjust the workplace to get enough space to change working position. Use a foot rail or portable footrest to shift body weight from both to one or the other leg. Use a seat whenever possible while working, or at least when the work process allows for rest.

What should workers avoid while working in a standing position? Avoid reaching behind the shoulder line. Shifting feet to face the object is the recommended way. Avoid overreaching beyond the point of comfort. Avoid reaching above shoulder line.

What are some do's and don'ts regarding footwear?Your feet can only be as comfortable as the footwear permits.DO wear shoes that do not change the shape of your foot.

DO choose shoes that provide a firm grip for the heel. If the back of the shoe is too wide or too soft, the shoe will slip, causing instability and soreness.DO wear shoes that allow freedom to move your toes. Pain and fatigue result if shoes are too narrow or too shallow.DO ensure that shoes have arch supports. Lack of arch support causes flattening of the foot.DO wear shoes with lace-up fastenings.DO tighten the lace instep of your footwear firmly. The foot is prevented from slipping inside the footwear.DO use padding under the tongue if you suffer from tenderness over the bones at the top of the foot.DO use a shock-absorbing cushioned insole when working on metal or cement floors.DO choose footwear according to the hazard at your workplace.DO select safety footwear, if required, that is CSA approved and carries the proper ratings for the hazard. DO select footwear taking into account individual fit and comfort. Try them on and walk around for a few moments before buying.DO NOT wear flat shoes.DO NOT wear shoes with heels higher than 5 cm (2 inches).

What do we recommend regarding floors in a workplace? Keep work areas clean. Avoid standing on concrete or metal floors. Recommended for standing work are wooden, cork or rubber covered floors. Ensure that the floors are level and non-slippery. Cover concrete or metal floors with mats. Slanted edges on mats help prevent tripping. Do not use thick foam-rubber mats. Too much cushioning can cause fatigue and increase the hazard of tripping.Working in Sitting/Standing positionsWhat is an example of a workstation for sitting/standing?Continuous standing or sitting while working is a common source of discomfort and fatigue. Frequent changes of body positions, including alternating between sitting and standing, helps to avoid fatigue. Adjust the workstation to the proper height. Use a swivel chair with an adjustable seat height. Adjust the chair seat height to 25-35 cm (about 10 - 14 in.) below the work surface. Use a footrest with a height of 40-50 cm (about 16 - 20 in.).

What is an example of a semi-circular workstation? Arrange work in a semi-circle. Use a swivel chair to reduce body twisting, to allow easy movements, and to reduce side-to-side motions. Use sloping work tables whenever possible to reduce bending, and to encourage an upright position while sitting or standing.

What are examples of a chair for sitting/standing workstations?Whenever possible, a worker should be able to work sitting or standing at will. Ensure that the seat has a minimum width of 40 cm (about 16 in.). Choose back rests that are contoured vertically and horizontally. Use a seat covering of non-slip, breathable fabric. Select seat padding that is about 2-3 cm (1 in.) thick.

Provide a chair that can fold up and be stored out of the way where space is limited. Ensure that chairs have a back support. Provide a chair for resting purposes even when work can only be done standing.

Working in a Sitting PositionAlternative ChairsWhat are examples of "alternative" chairs?The forward sloping chair and the kneeling chair are alternatives for workers who sit continuously. A saddle chair (sit-stand seat) allows a worker to alternate between sitting and standing.What is a forward sloping chair?A forward sloping chair has a mechanism that allows the user to adjust the tilt of the seat pan forward. The angle of tilt from the horizontal should not be greater than 10 degrees.

What are some advantages of a forward sloping chair?The use of a forward sloping chair: Increases the number of possible positions. Provides better alignment for spine. Improves visual distance and angle to the task on a worktable. Improves head position. Improves return blood flow from the lower legs. Decreases pressure on internal organs.What are some disadvantages of a forward sloping chair?The use of a forward sloping chair: Places more weight on legs to control forward tilt of the upper body, and may result in earlier development of tiredness. May cause the body to slide forward; however, if the seat pan of such a chair is curved from front to back, it would allow you to sit without sliding. Nevertheless, you do have do exert some muscular effort in your lower legs to remain seated. This effort is in fact beneficial (providing the slope is not greater than 15 degrees) because it improves the return blood flow from your lower legs. May cause clothing to ride up legs.

What is a kneeling chair?A kneeling chair has a fixed seat sloping at 30 degrees forward and padded support for knees.

What are some advantages of a kneeling chair?A kneeling chair: Provides proper alignment for the spine. May be good for some people if fitted to the individual. Provides considerable comfort for short periods of time.What are some disadvantages of a kneeling chair?A kneeling chair: Causes shins to bear weight. Over-flexes knees and ankles. Limits the number of possible sitting positions. May cause fatigue to develop earlier. May cause clothing to ride up legs. Makes getting in and out of the chair difficult. Reduces the range of reaches.When would you use a saddle chair or a sit-stand seat?A saddle chair can be used where the worker can alternate between sitting and standing in his or her work.A saddle chair: reduces fatigue by decreasing muscular effort improves alignment of the spine

Combining the saddle chair with a tilted worktable, where possible, is beneficial because it: improves the head position and reduces stress on shoulders and neck.

Alternate sitting and standing frequently.Are there some other things I should know about alternative seating?There are situations when rest chairs and sitting/kneeling support should be made available.Rest Chair. It is desirable to have a chair for resting even when work can only be done standing. If space is limited, then chair that can be folded up and stored out of the way can be used.

Sitting/Kneeling Support. Making hip support available where the work requires kneeling: reduces tension in the thigh muscles, by widening the angle of the knees reduces compression on the knees, ankles and lumbar region (middle to lower back) improves blood circulation

Do not maintain kneeling/sitting position for extended periods. Avoid bending. Stand up and walk whenever possible.

Basic RequirementsThe basic requirements are to have a workstation and job tasks designed to allow a person to remain in a balanced position or neutral posture, regardless of the work being done.WorkstationA workstation should allow the worker to sit in a balanced body position. Use a workstation that ensures that the alignment of the spine is the same whether the worker sits or stands. Use a workstation that allows the worker to move the spine freely. Use a workstation that can be adjusted to the needs of the worker.Job designA job design should allow the worker to work in a variety of balanced positions. Design tasks so they require movement of the spine and encourage the worker to alternate positions frequently. Avoid an excessive range of movement by: providing all materials at working level positioning tasks within easy reach avoiding lifting and transferring loads while sitting. Avoid static positions. Position visual tasks that maintain the vertical alignment of the head and spine Design the lighting system to: provide good general lighting. provide task lighting where necessary. avoid glare.

What is meant by a neutral posture or balanced position?Gravity constantly exerts a downward force on our bodies. Parts of your body in contact with a supporting structure (the seat of chairs, armrests, floors, etc.) will feel pressure from the structure to balance this force. Parts of our bodies that are not in contact with a supporting structure will use muscles, tendons, and ligaments to balance the force of gravity with an upward force of their own.The body position that has the highest strength to handle the pressure felt by the supporting structure, while causing the least amount of strain on the muscles, tendons, and ligaments, is called the neutral or balanced body position.The following recommendations outline how to maintain a neutral body position while sitting: Hands, wrists, and forearms are straight, in-line and roughly parallel to the floor. Head is level or bent slightly forward, forward facing, and balanced. Generally it is in-line with the torso. Erect or upright spine. Shoulders are relaxed and upper arms hang normally at the side of the body. Elbows stay close to the body and are bent between 90 and 120 degrees. Feet are fully supported by the floor, or a footrest may be used if the desk height is not adjustable. Back is fully supported with appropriate lumbar support when sitting vertical or leaning back slightly. Thighs and hips are supported by a well-padded seat and generally parallel to the floor. Knees are about the same height as the hips with the feet slightly forward. No twisting of the upper torso. The in-line sight is between the horizontal and 350 below the horizontal.Note:No one seating position can remain comfortable over a long period of time. For this reason, multiple positions in which the body can be in the neutral position are recommended. As mentioned above, the workstation should allow the worker to adjust and move between these positions. The first diagram below outlines the most common position used to design workstations for individuals. The second figure provides guidance on alternative seating positions that also allow the body to be positioned in a neutral position.

Figure 1 Design reference posture for sitting (Canadian Standards Association, CSA Z412.00)

Figure 2 Dynamic sitting posture (Canadian Standards Association, CSA Z412.00)How should manual tasks be designed?Seated manual tasks should be designed to maintain vertical alignment of the spine, and avoid constant stress on the shoulder region. This can be done by: providing materials at or slightly below elbow height Providing arm rests where appropriate providing tool balancers and avoid heavy hand tools avoiding tasks that require the shoulder or arms to be excessively high (keep below 15 cm above the surface of the work surface) avoiding tasks that require excessive reach -- The example below provides some general reach guidelines. (Adapted from CSA412-00).Note:this guideline should be used with caution as the posture of each individual should be observed to ensure the body maintains its neutral position during the cycle of work.

Figure 3 (Metric) General guidelines for work reaches (Canadian Standards Association, CSA Z412.00)

What should be considered when a foot task is necessary? Position foot tasks so that they can be done without twisting hips. Design foot tasks to avoid movement and exertion by only one leg. Provide the appropriate support for both working and non-working leg. Design a sitting task that encourages the worker to alternate positions frequently.Good body positionWhat is a good sitting body position?There is no one or single body position that is recommended for sitting. Every worker can sit comfortably by adjusting the angles of their hips, knees, ankles and elbows. The following are general recommendations. Occasional changes beyond given ranges are acceptable and sometimes beneficial. Keep the joints such as hips, knees and ankles open slightly (more than 90). Keep knee joints at or below the hip joints. Keep ankle joints in front of the knees. Keep a gap the width of three fingers between the back of the knee joint and the front edge of the chair. Keep feet flat on the floor or on a foot rest.

Keep the upper body within 30 of an upright position. Keep the lumbar support of the back rest in your lumbar region (around the waistband).

Always keep the head aligned with the spine. Keep upper arms between vertical and 20 forward. Keep elbows at an angle between 90 and 120. Keep forearms between horizontal and 20 up. Support the forearms.

Keep the wrists straight and aligned with the forearms. Place the working object so that it can be seen at viewing angle of 10 to 30 below the line of sight.

Keep shoulders low and relaxed. Keep elbows tucked in. Tuck chin in and do not bend forward when looking down and forward. Change positions frequently but remain within recommended ranges. Alternate crossed legs. Avoid bending to the side. Avoid bending forward. Do not slouch. Do not sit for more than 50 minutes at a time.What to avoid while sittingWhy is body position or posture important while sitting?Poor arrangement of the workstation encourages an awkward body position. A poor body position or posture can hinder breathing and blood circulation and contribute to injuries affecting people's ability to move.What should I avoid while sitting? Tilting the head forward. This helps prevent neck injury. Sitting without lumbar support. This helps prevent back pain. Working with arms raised. This helps prevent neck and shoulder pain. Bending wrists. This helps prevent muscle cramps. Working with unsupported forearms. This helps prevent shoulder and back pain.

Cramming thighs under a worktable. This reduces blood circulation. Sitting on a chair that has poor support. It can overturn and cause injuries.

How does sitting on a chair that is too high affect your body? It destabilizes your body causing tiredness. It puts pressure on your thighs. This reduces the back flow of blood and can cause swelling in the legs, varicose veins, and swelling in the ankles. It puts pressure on the sciatic nerve causing pain or discomfort. It prevents proper use of the chair's lumbar support.How does sitting on a chair that is too low affect your body? It disrupts blood circulation in lower legs, causing swelling. It puts pressure on internal organs. It creates too much pressure on buttocks and causes discomfort.

How does work at a worktable that is too high affect your health? It prevents use of proper lumbar support and can cause back injury. It over-stretches spine and can cause back injury. It forces the head to tilt forward and can cause neck injury. It stresses shoulders and causes pain. It tires the whole body.Work chairsWhat is the basic requirement of a work chair?A good work chair can support the body in a dynamic posture, while also being appropriate to the task or activity performed. This means it is easily adjustable into positions that support the spine and keep the body in a neutral position.What should I consider when selecting an office chair? Check that the adjustability range can accommodate the workers' body sizes. Select a chair that allows the worker to adjust the height and depth of the seat as well as the height and tilt of the backrest. An adjustable seat tilt is also desirable. Select a chair with: a backrest that is shaped to support the lower back and does not give way; a seat height that does not compress the underside of the thighs; a front edge curved downwards; non-slip, breathable fabric on the seat; stable base (5 legs); with arm rests (where practical) Use a footrest when feet cannot rest on the floor.

What else should I consider when choosing a chair if my work involves both sitting and standing? Make sure the wheels (casters) are made of the right material for the floor where the chair will be used. For example plastic casters are best on carpets, while rubber casters are for hard surfaces(concrete, laminate, wood, etc.) If using a mat under a chair, be sure the mat is large enough to keep all 5 wheels on the surface (if a wheel sits off the mat, the weight in the chair will not be evenly distributed). Make sure the caster type matches the mat surface. Ensure that the chair has a wheel locking mechanism, when appropriate. Use a swivel chair with an adjustable seat height. Adjust workstation to the proper height. Adjust the chair seat height between 25 to 35 cm (about 10 to 14 in.) below the work surface. Use a footrest with a height of 40 to 50 cm (about 16 to 20 in.)

Example of a chair for sitting and standing

Example of a sitting and standing workstationExtended work dayWhat is meant by the extended work day?Extended workdays refer to work schedules having longer than "normal" workdays. However, there is no clear consensus about the length of the extended workday. Some sources consider it to be between 8 to 12 hours in length, while others insist that the term applies only when shifts are longer than 12 hours.Usually workers on extended workday schedules work fewer than five days a week. When the traditional thirty-six to forty-hour workweek is squeezed into three or four days, the number of days worked in a row is decreased and the number of consecutive days off is increased. This is not always the case; therefore, working on an extended workday schedule does not automatically mean the same as a compressed workweek.In general, what are some advantages and disadvantages of extended workdays?Work schedules are important for both the organization and the worker. They affect the worker's health, safety, and family and social life.Many hospital, industrial, transportation, mining and office organizations are adopting the extended workday based on the assumption that it offers some advantages. However, the decision to set up longer work shifts (up to 12 hours or more) should not be made lightly. Studies on this subject do not provide sufficient evidence to decide categorically in favour or against the use of extended work shifts. The following are examples of the "pros" and "cons" of this issue:Advantages More days off and more consecutive days off More family and leisure time More rest days to recover from fatigue Fewer consecutive workdays Improved morale Increased job satisfaction Reduced absenteeism Reduced time of commutingDisadvantages More days off and more consecutive days off Workers lose the touch with their operations Long traveling time or exhausting recreation may cause fatigue on return to work Decline in safety and alertness Slower pace of work Workers need more breaks

What should I know about "fatigue"?Fatigue is a message to the body to rest. It is not a problem if the person can and does rest. However, if rest is not possible, fatigue can increase until it becomes distressing and eventually overwhelming.The symptoms of fatigue vary and do depend on the person and their degree of fatigue or sleep deprivation; some examples include: weariness sleepiness irritability reduced alertness, concentration and memory lack of motivation increased susceptibility to illness depression headache giddiness loss of appetite and digestive problemsMany conditions can lead to fatigue. For example, fatigue resulting from long hours of work and a shorter length of time between work shifts is an important concern for the health and safety of workers on extended workdays. Some researchers report that in many cases the extended workday is more tiring than the eight-hour day. They often argue that workers will be too tired by the end of ten or twelve hours and jeopardize their own well-being, and also the safety of others on the job.Others report that the eight-hour work schedule is tiring, particularly when many consecutive shifts must be worked with few consecutive days off. The advantage of properly designed extended workday schedules over eight-hour day schedules is that fewer consecutive shifts are required and longer periods off between "workweeks" allow for better rest. The longer time off may compensate for longer workdays, if the worker maintains healthy and regular sleep patterns.Another concern about the extended workday is that during the workweek, workers can only do their job, eat and sleep. This creates two problems. First, most workers need a certain amount of time to relax after work and before sleeping. When there are only twelve or fourteen hours between shifts, this time is reduced. Second, workers with other types of responsibilities such as child care may find the extended workday tiring because they still have tasks to do when they return from work.Many workplace factors make physical and mental demands of the workers that affect health, mood, performance, safety and fatigue. Examples of such factors are job design, lighting, air quality and workstations. Reducing any source of fatigue helps workers deal with all of the demands of their work including the work schedule. For example, a well-designed tool, an extra rest break or a better chair can help reduce the overall demands of a particular job.

What are the issues surrounding "social life"?A primary advantage of the extended workday is that it provides more consecutive days off than most other types of schedules. This allows more free days for family and other activities. However, the disadvantage is that the long hours do not allow much free time on workdays. This can also affect family and social life. Whether the advantage of longer blocks of time off outweighs the disadvantage of little time off on workdays, or vice versa, is not clear and may depend on the individual.It appears that important factor for being able to adjust to an extended workday relates to characteristics such as age, marital status, parental status, hobbies, and personal interests. Workers who have major responsibilities outside work may have more difficulty with conflicting demands for time on extended workdays particularly the twelve-hour day. On the other hand, others may enjoy the longer time off and the opportunity for social and leisure activities.Time spent travelling to and from work is often viewed by workers as lost time. The extended workday means fewer commuting trips and, therefore, less wasted time and less cost.

What are the issues surrounding "safety"?An issue often raised is the effect of fatigue on workplace accident and injury rates. The concern is that increased fatigue will contribute to accidents. While this concern seems logical, it cannot be supported clearly with evidence. Of the few studies reporting accident rates, some show an increase whereas others found no change in accident rates. It is clear that an accident occurs as part of a process involving a combination of technical, personal, behavioural, environmental and work process factors. The length of the workday, as it relates to worker fatigue levels, is only one factor to consider when looking at what caused an accident. Fatigue levels are not easily measured or quantified; therefore, it is difficult to isolate the effect of extended workdays on any changes in accident and injury rates.What are the issues surrounding "exposure to physical and chemical hazards"?Exposure to physical and chemical hazards is always a health and safety concern. When the workday is lengthened, the amount of exposure needs to be reevaluated to ensure that acceptable levels are not exceeded. Areas of particular concern are exposures to chemicals, noise, vibration, radiation, and extreme temperatures. Any method for determining exposure levels for the extended workday should be used with caution and under supervision. Expert advice may be necessary to determine acceptable exposures and controls for an extended workday.The proper and efficient use of personal protective equipment during an extended workday should also be considered. For example, uncomfortable hearing protectors cannot provide protection if workers find them uncomfortable and do not wear them when they should. Comfort over the whole work shift is important to usage.What are the issues surrounding exposure to ergonomic hazards?Ergonomic hazards such as repetitive work or working in a sustained and or awkward posture increases the risk of developing a musculoskeletal injury. Repeated or extended exposure to these hazards causes the body to fatigue and muscles to be damaged. If the body does not have sufficient rest, then the body, specifically the muscles, cannot repair themselves. Damaged muscles can lead to injury through a cumulative loading effect or a one time peak loading effect.When designing extended day work schedules, it is important to factor rest breaks and alternate tasks that use opposing muscles groups to decrease the likelihood of sustaining a musculoskeletal disorder.What types of jobs are suitable for an extended workday?Perhaps the most difficult decision with the extended workday is what type of work is suitable for this schedule. There is no easy answer because studies have not been able to say a definite "yes" or "no" to any of the concerns. In most cases, having a trial period in the workplace to monitor the health and safety aspects of particular jobs and determine the level of worker acceptance would be beneficial. The physical and psychological effort required by a job, environmental conditions such as temperature and vibration, and job characteristics such as boredom and repetitive work all contribute to the acceptability of the extended workday.With these points in mind, some general statements can be made. The sparse information that is available shows that jobs that do not require a high degree of physical exertion or that have natural resting periods may be most suitable for the extended workday schedule. For example, a machinist who has cycle time between setups that allows reduced attention while the machine is running can probably work a longer day. On the other hand, a data entry operator who must continually enter data while sitting in one position and concentrating for long periods would find the extended workday more difficult. People whose work involves creative activities may benefit from this type of schedule as it allows them to work intensively on projects while providing more time away to rest.Workers on eight-hour rotational shiftwork schedules might prefer the extended workday because it requires fewer consecutive night shifts and allows more recuperative time.In spite of inconclusive studies and conflicting worker responses about the most suitable length of work shifts, it is probably fair to say that heavy physical jobs and/or jobs that demand sustained attention throughout the workday do not lend themselves well to extended workday schedules. More suitable jobs would be those that require only light or intermittent work.What are some guidelines for using an extended workday?First, find out if there is any legislation in your jurisdiction that requires government approval to schedule more than eight hours of work per day and to average hours over longer periods. The legislation may require the organization to show that workers are aware of and understand the implications of the extended workday, and that workers genuinely want to work such a schedule.Some guidelines to consider when deciding whether to start or continue using an extended workday schedule are: Consult workers about their desire to have a change in the work schedule and specifically an extended workday. Consider the physical demands of jobs, occupational hazards such as chemicals or noise exposures, and aspects of job design such as rest schedules. Changes in the environment or job design can sometimes make an extended workday more acceptable. Consider the mental and emotional demands of the job. Work that requires constant attention or intense mental effort may be less acceptable for the extended workday. Use additional rest breaks or variation of job tasks to help decrease the strain of the extended workday. Consider the workers and the other demands on their time. People who have other significant responsibilities each day may require additional support such as child care facilities. Seasonal demands may also have to be considered.If the decision is made to try the extended workday, establish an experimental period. Introduce the extended workday gradually to small groups to allow more flexibility and better analysis of the situation. Evaluate the success of the new schedule by doing the following: Monitor health and safety. Look for any changes in accident rates, health levels and especially fatigue. Look for any changes in absenteeism rates. Although absences are not always a good measure of health or ill health, an increase may suggest a problem. On the other hand, a decrease may show that the extended workday is successful. Ask for workers' reactions and listen to their comments to find out how satisfied they are with the extended workday, and how well they have accepted it and adapted to it.