Win an ipad 2 at BN Office Solutions at Clerkenwell Design Week

BN Office Solution have partnered with digital creative agency Crystal CG and will be showcasing modern design trends, visuals, animations and renders as well as discussing the latest technologies available to today’s designers. Focusing on all things digital, BN Office Solution will be showing several creative loops in their showroom from one of the leading digital rendering and animation companies. Crystal CG specialise in architectural, sport and experiential visualisations and environments and are currently in the throes of producing a range of digital imaging work for the London 2012 Olympic and Paralympic Games.

As well as having the open showroom, On Wednesday 23rd at 4:30 pm – The world renowned Ximo Peris and Darren Groucutt will be hosting a talk and presentation that will showcase some of Crystal CG’s ground breaking work and modern technologies within today’s 3D visual design and animation world. There will be refreshments served throughout the early evening and there will be the chance to quiz the presenters after the talk.
BN Office Solution will also be a stop on the RIBA Journal smart shot passport which offers you the chance to win an iPad 2, there will also be a competition to win a weekend away in Krakow, Poland.

100 Years of Great Design at Steelcase

Join Steelcase in their centennial year as they celebrate 100 Years of Great Design.

As part of Clerkenwell Design Week 2012, they will explore the past, present and future of great workplace design with a series of talks and product installations:

22nd May, 12.30pm: Explore the design partnership between Steelcase and Frank Lloyd Wright, including the iconic Johnson Wax building

23rd May, 1pm: Share the latest Steelcase research exploring the global trends that influence the Interconnected Workplace

24th May, 1pm: Join our 100 Minds member Victoria Redshaw of design trends forecasters Scarlet Opus as she looks to the future of great design

The London WorkLife showroom, will also be operating an ‘open house’ each day between 10am and 5pm when you can drop by the showroom to view some iconic Steelcase products from the last 100 years including the Frank Lloyd Wright/Steelcase desk and chair.

RSVP to: gsapra@steelcase.com

Your chance to win a Z-Bar task light and X-Stream monitor arm, exclusively with CMS Ergonomics

To be in with a chance of winning one of CMS Ergo’s beautiful and sleek Z-Bar task lights or an X-Stream monitor arm, simply pop into their showroom, have a play with their products and drop your business card into their competition box.

CMS are located at:

The Gallery
21-22 Great Sutton Street
Clerkenwell

London EC1V 0DY
T: +44(0)20 7253 7652

Work Related Musculoskeletal Disorders (WRMSD’s)

So what can happen when the needs of the human body are not addressed when performing daily tasks? The question that you must first consider is ‘what is comfortable?’ 

This may seem like a straight forward concept, but when you think of the variety of positions that you assume throughout the course of a day, the answer may not seem as obvious as first thought.  At rest our bodies naturally seek to find the most ‘neutral’ position they can find.  This is a position in which the body expends the least amount of muscular effort in supporting itself.  For example sitting in our favourite armchair or standing with weight shifted onto one leg while we rest the other one.  So, notions of comfort are not necessarily tied to fabric and upholstery. 

We are dynamic beings, so changing position not only helps to rest muscle groups, the flexing of muscles and joints helps to circulate the blood through the body, drawing nutrients into cells and expelling toxins.  The key thing is that we can change position whenever we feel like it, resting various tired muscle groups whilst bringing others into play.

This picture changes somewhat when we have a specific job to do.  At work, our postures are dictated by the task rather than our body’s natural tendency to seek a neutral position, as a result, as bodily fatigue increases, the task limits what we can do to rest these tired muscle groups.

Technology is now an integral part of the office landscape – computers, mobile communications, internal and external networking and wireless working environments.  We can work anywhere at any time, however, these benefits of flexibility and productivity have come at a cost.

The professional office worker spends approximately 70% of their time sat at their desk, usually for 45 minute periods at a time.  Deskbound workers such as call centre employees can spend in excess of 90 % of their time sat at their desk.

The effects of these working environments are twofold – psychological and physiological.  Over the next few sections we will explore the various aspects of reducing the physiological challenges imposed by technology in the workplace.

The main health problems associated with technology in the workplace and in particular DSE work are a range of disorders known as Musculoskeletal Disorders (MSD’s).  They are sometimes referred to by a number of other names: Repetitive Strain Injuries (RSI’s) or Upper Limb Disorders (ULD’s) .

Some examples of MSD’s you may have heard of are Tendonitis, Tenosynovitis and Carpal Tunnel Syndrome.  They are all injuries to the joints, tendons, nerves, muscles and soft tissues of the body and are caused by repetitive use over an extended period of time.  The majority of these MSD’s are concentrated in the upper body – the neck, shoulders, upper limbs and hands, in particular, injuries to the neck and shoulders and becoming more common.

Lower back pain is also strictly speaking an MSD, but can often be caused by a number of different factors, many of which are outside of the workplace.  It is a wide spread problem with approximately 80% of the population in the UK suffering from some form of lower back pain at some point in their working lives.

Eye stain and visual fatigue is also another common problem associated with DSE work.

Common examples of hand and wrist MSD’s:

Carpal Tunnel Syndrome:             Swelling of the carpal tunnel inside the wrist, placing pressure on the median nerve and tendons.

Raynaud’s Phenomenon:             Increased sensitivity of the hand to cold.

Trigger Finger:                            Catching and pain that occurs with movement of the finger.

Common examples of arm and shoulder MSD’s:

Rotator Cuff Syndrome:               Tendonitis of the rotator cuff inside the shoulder.

Epicondylitis:                              Tendonitis of the elbow

Lower back and neck MSD’s:

Herniated spinal disc:  Protrusion of the spinal disc, potentially placing pressure on a nerve.

Sciatica:  Pressure on the sciatic nerve in the lower back and buttocks area that results in pain running down the  leg.

Tension Neck Syndrome:  Tightening of the muscles in the neck, causing pain.

 The typical causes of work related MSD’s are:

Awkward postures – The body will naturally seek neutral postures which exert minimum strain and effort on muscles and joints. When we perform any task we often need to force the body into non-neutral postures. The more extreme the nature of these postures, the more damaging they might be.

• Bending your wrists
• Holding your elbows away from your body
• Stretching your arms out
• Sitting or standing with your back rounded or shoulder slumped forward
• Making long reaches for documents or materials

Even in fairly neutral postures, it is not good to maintain a static position for too long. Over a period of time they can lead to fatigue and a drop in productivity.  We are dynamic beings. Changing position permits us to rest certain muscle groups whilst bringing other into action. In addition, the flexing of our muscles and joints helps circulate blood through the body, draws nutrients into cells and helps to expel toxins.

Localised pressures – e.g. arms writs on edge of desk – can limit blood circulation, trap nerves, etc.

Use of excessive force or strength – e.g. hammering at keyboard can cause local soft tissue damage.

• Holding a pen too tightly
• Moving equipment or supplies
• Striking keys harder than necessary when typing or data entry
• Clicking a mouse harder than necessary

Repetitive activity -This is not automatically a bad thing in itself. However, if any of the above mentioned problematic factors are present, then repetition will rapidly multiply the effects.

• Data entry, typing and using the mouse
• Sorting
• Filing

In addition, certain individuals may have a predisposition to certain disorders, either due to physical characteristics, or due to activities outside of the workplace. This must be borne in mind when assessing workplace health problems of any individual.

The affects of MSD’s can be reduced still further if you are mindful your body and its movements.  For example, if you spend good part of our work day at a computer, pay attention to how you position your arms and wrists.  To reduce muscle strain on your upper body, keep your elbows close to your body, your shoulders down and relaxed and as much as possible; work with your forearms, wrists and hands in a relaxed and neutral position.

Also thinks about your posture.  When you sit or stand, try to maintain the neutral inward curve of your lower back.  Keeping your lower back in this position helps align your neck, head and shoulders and also reduces the stress to your lower back.  In addition aligning your head over your shoulders reduces the strain on your neck and improves the blood flow to the upper body.

Finally, be sure to give your body a rest by taking regular short or micro breaks throughout the working day.  This can be as simple as taking a break from one task and performing another e.g. switching from typing to making a phone call or adopting a sit down stand up work routine.  If the work is nearly all computer based, then every 15-20 minutes, look away from the screen and focus on something further away for at least 20 seconds – and remember to blink! When focusing on screens or reading etc. the rate of blinking falls considerably and this can lead to dry and tired eyes.

Laptops – Ergonomic set up guide (United Kingdom)

Due to their design, laptops are not very ergonomic. The design prevents the screen and keyboard from being separate (mimicking the set up of a PC) and so makes it very hard to achieve a good working posture.
• Neck, shoulder and eye strain from working in awkward postures
• Wrist and hand problems from using the keyboard and touchpad/nipple mouse for prolonged periods

What to look for in a laptop:
• Light weight
• Balance of screen size vs. portability
• Long battery life – reducing the need to carry charger, cables etc.
• Touch pad mouse rather than the ‘nipple’ mouse device
• Enough USB inputs to facilitate separate USB or wireless mouse, keyboard & CD Rom etc.
• Sufficient memory and processing power to handle the applications required

Ideally you should use a separate monitor and keyboard – most manufacturers will offer docking stations, which allows a more permanent ergonomic solution to be created on any work station in conjunction with the separate monitor and keyboard/mouse.

However, if these are not available:

• Sit in a position where arms and wrists can be kept in a neutral position, with shoulders relaxed and the back supported.
• Ensure the monitor and screen of the laptop is lined up centrally to the body – the letter ‘B’ is lined up with the belly button.
• Extended use is not recommended. If you must use a laptop without ergonomic aids, periods of 15-20mins of use before taking a break are recommended.

Display Screen Monitor or Computer Monitor – Ergonomic set up guide (United Kingdom)

• Screen image should be legible, flicker-free, stable, adjustable brightness & contrast, appropriate character size. Also free from glare & reflections. It should also tilt & swivel easily to suit user’s needs. 
• Keyboard shall be tiltable and separate from screen so as to allow user to find a comfortable working position avoiding fatigue in the arms or hands. Sufficient space in front of keyboard to provide support for the hands or arms of the user. Keys to have matt surface and legible symbols.
• The monitor should be placed directly in front of you and facing you, not angled to the left or right. This helps to eliminate too much neck twisting. Also, whatever the user is working with, use the screen scroll bars to ensure that what is being viewed most is in the centre of the monitor rather than at the top or bottom of the screen.
• Centre the monitor so that the body and/or neck isn’t twisted when looking at the screen. However, if you are working with a large monitor and spend most of your time working with software like MSWord, which defaults to creating left aligned new pages, and you don’t want to have to drag these to more central locations, try aligning yourself to a point about 1/3rd of the distance across the monitor from the left side.
• Put the monitor at a comfortable height that doesn’t make you tilt your head up to see it or bend your neck down to see it. When you are seated comfortably, a your eyes should be in line with a point on the screen about 2-3″ below the top of the monitor casing or bezel. Sit back in your chair at an angle of around 100-110 degrees (i.e. slight recline as you would in a car seat to drive) and hold your arm out horizontally, your middle finger should almost touch the centre of the screen. From that starting position you can then make minor changes to screen height and angle to suit. Research shows the centre of the monitor should be about 17-18 degrees below horizontal for optimal viewing, and this is where it will be if you follow the simple arm extension/finger pointing tip. You actually see more visual field below the horizon than above this (look down a corridor and you’ll see more of the floor than the ceiling), so in this position you should comfortably be able to see more of the screen. If the monitor is too low, you will crane their neck forwards, if it’s too high you’ll tilt their head backwards and end up with neck/shoulder pain. 
• If text looks too small then either use a larger font or magnify the screen image in the software rather than sitting closer to the monitor.
• Document holders – use an in-line document holder that sits between the keyboard/keyboard tray and screen and is aligned with your body midline so that all you have to do is look down to see the documents and raise your eyes to see the screen. Or use a  screen-mounted document holder and position this to the side of your screen that is your dominant eye. 
• Eye breaks – looking at a computer screen for a while causes some changes in how the eyes work, causes you to blink less often, and exposes more of the eye surface to the air. Every 15 minutes you should briefly look away from the screen for a minute or two to a more distant scene, preferably something more that 20 feet away. This lets the muscles inside the eye relax. Also, blink your eyes rapidly for a few seconds. This refreshes the tear film and clears dust from the eye surface.
• Micro-breaks – most typing is done in bursts rather than continuously. Between these bursts of activity you should rest your hands in a relaxed, flat, straight posture. During a micro-break (< 2minutes) you can briefly stretch, stand up, move around, or do a different work task e.g. make a phone call). A micro-break isn’t necessarily a break from work, but it’s a break from the use of a particular set of muscles that’s doing most of the work (e.g. the finger flexors if you’re doing a lot of typing).
• Rest breaks – every 30 to 60 minutes you should take a brief rest break. During this break stand up, move around and do something else. Go and get a drink of water, soda, tea, coffee or whatever. This allows you to rest and exercise different muscles and you’ll feel less tired.
• Exercise breaks – there are many stretching and gentle exercises that you can do to help relieve muscle fatigue. You should do these every 1-2 hours.

The Keyboard and Mouse – Ergonomic set up guide (United Kingdom)

• The first ergonomic consideration for the keyboard and mouse is height.  Your chair and seated position should be relative to the height of the desk and your position to the work surface and keyboard.  In general terms this means the keyboard and mouse should be just below your elbow height when your forearms are parallel to the floor.
• Work surface should have at least 100mmn – 150mm free space in front of any input device, this space can be used  to support the hand or wrist.
• Work surface edge should be shaped to avoid cutting into the wrist.
• When seated in a comfortable position relative to the desk, your arms should rest at your sides, forming a 90 degree angle at each elbow.  The keyboard should rest on the desk, set in a negative tilt position, which means that the front of the keyboard (space bar edge) is lower than the back (although some now recommend that the keyboard be flat).  To ensure that the keyboard is fully centralised, the letter ‘B’ should be in line with your bellybutton.
• Always ensure that your wrists are in the neutral position, which means the hands and wrists are in line with your forearms. Be gentle, use a soft keying action – do not ‘hammer’ the keyboard.
• Learn to use shortcuts on the keyboard rather than always using the mouse. Most shortcut key combinations are displayed alongside the relevant item in the pull down menu of the application.
• Don’t lean your wrists or forearms on the desk when using the keyboard this puts a direct pressure on the wrists. If you rest your wrists whilst inputting get a wrist support or drop the level of the keyboard.
• When handling a mouse, keep your hand and wrist in line with the forearm.  Avoid bending the palm at the wrist; either to the right or left or up and down. 
• Avoid mouse shapes that may cause the fingers or wrists to be bent sideways or upwards when grasping the mouse.
• If you choose to use a wrist rest, using one with a broad, flat, firm surface design works best, and rest the heel of your palm on this NOT your wrist. Try not to rest your hands on the support while you’re actually typing, but rest them in between bursts of typing movements. Avoid soft and squishy wrist rests because these will contour to your wrist; restrict the freedom of movement of your hands.
• Wrist supports should only be used in between periods of keying or mouse work.  Your hands and wrists should hover over the keys. Otherwise the use of a rest will compress the carpal tunnel and inflame the median nerve…

The Office Desk – Ergonomic set up guide (United Kingdom)

Workstations

• If the desks/worksurfaces are to be used for tasks where people can alternate between sitting and standing, the minimum height adjustment range should be 660 to 1200mm (preferred range is 600 to 1300mm). The height adjustment range for standing only work surfaces should be at least between 900 and 1200mm.
• The height of the desk should be suitable for everyone who is required to use the workstation. If the desk is non-adjustable, a height of 740mm can accommodate 95 per cent of the population. However, shorter users would require a footrest to enable them to achieve a satisfactory working posture. A height adjustable desk (from 660mm to 900mm) can accommodate everyone without a footrest.
• The work surface of a desk should be large enough and flexible to accommodate all equipment and paperwork in an arrangement acceptable to the user i.e. visual display unit, keyboard, documents and other related equipment.
• The depth of worksurface should be determined by the eye to monitor distance which is 600 mm ± 150 mm depending on the size of the monitor and the legibility of information displayed. This means that CRTs would require a desk of much greater depth than flat screens. However, flat screens do not mean that we can reduce the desk depth. This is because, people at these workstations naturally have legs which they have to place under the desks. Hence, they require a minimum legroom depth, which has to be calculated for the 95^th percentile male (the tallest of the user population). BS EN ISO 9241 Part 5 implies that, a desk depth cannot be less than 800 mm. The optimum eye to monitor distance for a small (15 inch) monitor in the seated position is 600mm. However, users have different preferences and distances between 450mm and 750mm are acceptable.
• For seated work, sufficient clearance between the underside of the worksurface and the floor and between the legs of the worksurface is needed. This allows the user to change position to maintain comfort levels and eases the use of VDU equipment and associated tasks because there is room for thighs, knees, lower legs and feet. BS EN 527 part 1 states that to achieve this, the user should be provided with a clear width of not less than 600mm beneath the worksurface, a clear depth of not less than 600mm from the front edge of the worksurface and a vertical space of not less than 650mm from the floor. However, these are only the minimum dimensions and larger clearances are preferable to give greater freedom of movement.
• The Health and Safety Executive‘s (HSE) guidance document on the Display Screen Equipment Regulations state that standards will provide specifications for new equipment, they may also be used as a yardstick for assessing the suitability of existing installations. The guidance notes go further by stating that workstations, which comply with the appropriate standards cited in the guidance, would meet, and in most cases exceed the relevant requirements of the Display Screen Regulations.
• The main standard mentioned in the HSE’s guidance document is BS EN ISO 9241, which has 17 parts. These cover all aspects of visual display screen work including computer equipment, furniture, task, environment, layout, and software. Although this CEN/ISO standard is not directly linked to the directive, one of its main aims is to set minimum health, safety and comfort levels for users.

As this standard is not a product standard actual dimensional requirements and safety requirements can be found in product standards which are summarised below. In order to ensure that desks and chairs are safe for the users they should comply with the following standards (info summarised from FIRA).

Standards applicable to desking:

• BS EN 527 Part 1 Dimensions,
• BS EN 527 Part 2 Strength and Stability or
• BS 6396 Cable Management
• BS 3962 Part 1 Gloss Measurement
• BS EN ISO 9241 Ergonomic requirements for office work with visual display terminals (VDT’s) Part 5 – work station layout and postural requirements

BS EN 527-1:2000

• Fixed height desks. The height of work surfaces shall be 720mm +/- 15mm.
• Height adjustable work surfaces shall have a minimum range of adjustment from 680mm to 760mm.

Health & Safety (DSE) Regulations 1992

• A footrest shall be made available to any operator or user who wishes one.

Minimum requirements for rectangular desks:

• Height 720 mm; (680 – 760 mm if adjustable)
• Depth 800 mm
• Length 1200 mm; (1600 mm preferred)
• The desk do not have to be a rectangular shape, it can be any shape provided that the surface area is adequate for the task and the equipment and it is not less than 0.96 square meters.
• Sufficient legroom underneath (specified in BS EN 527-1 and BS EN ISO 9241-5).

Shapes for desks:

Rectangular
• They do not need to be height adjustable (UK – see Netherlands)
• Fixed height 720mm
• Height adjustable 600-900 for sitting
600-1200 for sit stand
• Depth 800mm
• Length 1200mm (1600mm preferred)
• Sufficient leg room underneath

Non-rectangular – L-shaped, wrap around & wave front
• They do not need to be height adjustable
• Fixed height 720mm
• Height adjustable 600-900 for sitting
600-1200 for sit stand
• Area depends on sizes of equipment and nature of task (minimum area 0.96m2)

The Office Task Chair – Ergonomic set up guide (United Kingdom)

• For most office tasks, especially when working with a computer, the desk surface should be slightly below elbow level, when your arms are by your side and bent at a 90 degree angle. 
• Raise or lower the seat as needed to achieve the correct position.  If your feet cannot reach the floor when the chair is correctly adjusted in relation to the desk, the use of a foot rest or height adjustable desk would be ideal.  A foot rest should be made available to anyone who requires one.
• The appropriate height for a chair in practical terms means that when the feet are planted firmly on the floor, the thighs are approximately parallel to the floor.  This provides even support to the underside of the thighs without localised pressure, particularly to the backs of the knees.  This also helps ensure that the torso remains upright and the spine retains its neutral s-shaped curve (the lumbar curve).  A correctly adjusted chair also prevents the user from crouching forward and trying to support their body weight elsewhere, such as on the arm rests or the desks work surface. 
• Seat depth is also a factor.  A correct seat pan depth will allow the back rest to provide good supporting contact for the sitters back and still maintaining clearance between the front edge of the seat and the back of the sitter’s legs (approximately 2 fingers width).
• Most chairs offer some form of recline function.  In most situations the chair should be adjusted to recline about 10 to 25 degrees, similar to the correct driving position.  The other benefits of recline are mainly in the area of dynamic variation of posture – a chance to rest some muscle groups, whilst bringing others into action, reducing the amount of work being done by the spine and spinal muscles and transferring some of the torsos weight on to the chair back rest.  This function also opens up the angle between the torso and the thighs, reducing pelvic rotation and spinal deformation.  Extreme angles of recline should not been seen as alternative working postures.
• Arm rests can help support the weight of the arms and shoulders, reducing the load on the spinal structure and also provide additional support to the body when sitting down or standing up, when the body can be subject to extremely high transitional forces.  The armrest should be set slightly below elbow height.  In this way it can provide support when resting between periods of keying without interfering with arm movement when working. 
• For prolonged tasks involving intensive use of the mouse, some ergonomists suggest that support for the forearm whilst still permitting the appropriate movement of the hand and wrist.  However, it is important to note that arm rests can sometimes clash with the edge of the desk work surface.  If this prevents the user from adopting the correct position relative to the desk, then this problem could outweigh the benefits of armrest use.

The main requirements for an office seat are that:

The seat shall be stable and allow user easy freedom of movement and a comfortable position.  Shall be adjustable in height. Seat back shall be adjustable in height and tilt. Footrest shall be made available to any user who wishes one.

• Blood circulation to the lower limbs is not restricted
• It is easy to change and maintain a variety of postures with little muscular effort
• Loading or stress on the spine is minimised
• The seat surface has sufficient friction to avoid slipping off
• For thermal comfort, fabrics are permeable
• Compatibility with the work surface – especially height and the layout of equipment.

‘Independent height and tilt adjustment of backrest is not a requirement’.  The primary requirement is that is that user should be able to achieve a comfortable position. Other requirements are:

• seat should adjust in height
• backrest should adjust in height and tilt
• 5 star base with castors 

Standards applicable to task chairs

• BS EN 1335 Part 1 Dimensions
• BS 5459 Part 2 Strength and Stability for 24-hour use for people weighing up to 150kg or
• BS EN 1335 Parts 2 and 3 – Strength and stability for 8-hour use by people weighing up to 110kg
• BS EN ISO 9241 Ergonomic requirements for office work with visual display terminals (VDT’s) Part 5 – work station layout and postural requirements
• The appropriate seat height  for a seated user – popliteal height plus footwear thickness
• Backrest to give support to the back in all sitting positions. Particular support to the lumbar region.
• Lower edge of the backrest should start above the major protuberances of the buttocks and conclude below the level of the shoulder blades.
• Arm support should not restrict the user’s preferred working posture. Should not restrict access to the workplace, e.g. should not prevent chair from being slid under work surface.

What is Ergonomics?

Ergonomics examines the complex relationship between people (in all their variations of size, proportion and habit), the tasks they perform, the tools they use and the environment in which they carry out this work. It is a way of looking at the designs of tasks, tools, equipment and workplace layouts and the overall organisation of work to fit the job to the person, rather than the person to the job.

By understanding and implementing ergonomics, in other words analyse and adapt work to avoid potential health hazards, we can work in ways that decrease discomfort and the risks of on the job injuries, whilst increasing productivity and reducing the costs associated to a business of workplace injuries and absenteeism.

In addition to absenteeism, there is also the problem of presenteeism, which is when an employee shows up for work but performs at less than full capacity because of illness or other medical conditions. The effects of presenteeism are harder to measure than absenteeism, because these workers are in fact showing up for work. However, they tend to work at a slower pace, make more mistakes and produce lower quality work. Researchers estimate that in terms of lost productivity, the effects of presenteeism are 7.5 times greater than those of absenteeism.

Other direct costs include insurance coverage, worker’s compensation and covering for absent employees. The indirect costs include losing experienced staff and having to incur the costs of recruiting new staff and their subsequent training. Finally, there is also the potential legal costs stemming from employee lawsuits and government fines, the potential for which is increasing as employees become increasingly aware of the rights within workplace law.

The benefits of implementing ergonomics in the workplace may seem common sense and are very often viewed as unnecessary expense. They should however, be viewed as an investment in not only the business itself, but also an investment in it’s employees, their health and well being, but most importantly the continued retention and productivity.

While figures very, most ergonomic improvements are thought to increase worker productivity by 10% to 20%., given that the average worker is productive for just 5 hours a day (300 minutes), that equates to an increase of 30 to 60 minutes. With even just a 5% increase in productivity, that’s 15 minutes a day, or 1 hour and fifteen minutes a week. (M.F. Schneider “Why ergonomics can no longer be ignored”, office Administration and Automation, 46 (July 1985): 7, pp. 26-29)