Whether I am visiting a CEO or a call centre operator, when fitting chairs to people I keep getting asked whether it is the “Right” chair for them. As a Physiotherapist I can have an opinion of what I think is a great chair, but what I have found is that for each person a different chair may be required depending upon their needs in the workplace, and personal likes and dislikes. Below I have listed the main features of task chairs and the considerations with regard to them when making a choice.
Back Height: The Back Height of the chair relates to how high up the back the chair will support, generally speaking a mid back chair supports below the shoulder blades with emphasis on the lumbar region. A high back chair supports up to the shoulder blades. An Extra High Back chair will give upper back support and may involve a headrest for Head support. You should choose the Back Height that is comfortable for you when sitting and provides support to a particular area if you have a problem there, i.e. Medium back for lower back issues, high back for Shoulder issues.
Back Shape Square or Oval: The shape of the Back is generally an Aesthetic, although some people may find different back shapes mould to the body differently providing better support. So this choice comes down to the look you want versus the comfort you feel when seated in the chair. A point to consider is that some back shapes will allow for more arm movement when keying by not contacting the elbows.
Back Support: Probably the most important feature of the chair is the level of Back support. How much there is and where it is provided. Different Back shapes and chair moulds will provide different support. The Lumbar or lower back curve should be pronounced with the remainder of the back shape having a slight curve or moulded body shape. Remember everyone is different and will find different back contouring more or less comfortable. The Lumbar support should always be height adjustable, some chairs can also offer depth adjustment on the lumbar support. This way the user can adjust the lumbar support to the correct height and depth while in the chair, and change it when required. Seated Imprint, Empact and React Chair Ranges can be optioned with an adjustable AIR lumbar pump to increase or decrease the level of Lumbar support. Whilst our Orthopod & bExact Chair Ranges have fully adjustable Back tension.
Seat Size: Would be the 2nd most important consideration, when seated with your bottom at the back of the chair contacting the Back support the seat length should extend along the thigh and stop short of contacting the back of the knee joint, so that there is no contact between the front edge of the seat and the back of the knee. This gap should be approximately the width of 3 fingers. If the seat is too long the user will get contact and pressure on the back of the knee joint, which can lead to blood flow/compression issues. It can also cause the user to sit on the front edge or further forward on the chair resulting in less back support when seated. If the Seat is too short the user will get less support along the Leg creating a sensation of perching, this can also lead to increased pressure on the back of the mid thigh. Another factor is seat width, if the seat width is not wide enough the user can hang off the side of the chair creating pressure points.
Seat Moulding: Always make sure your chair seat is comprised of some form of high quality High Density Foam. Some chairs will have a moulded foam shape, make sure this shape feels comfortable and fits your bottom shape. Other chairs will have a flat foam, allowing the seat to mould to you. Modern technologies such as memory foam and gel seats will allow the seat to adapt and change for each individual user.
Mesh Vs Upholstered: An upholstered chair is normally a foam moulded backrest with fabric upholstery, providing a fitted back shape with lumbar support. Some upholstered chair backs can have lumbar adjustability via the use of strapping, tension dials and inflatable air supports. Most Physiotherapists and Occupational Therapist’s will recommend upholstered style chairs with good lumbar support for clients with back issues. Mesh chairs are a modern variant in seating, preferred by designers for their slim back design and stylish looks. Most mesh chairs should have an adjustable form of lumbar support to be considered ergonomic. Generally the more adjustable lumbar supports ie depth and height, provide a better level of support. Mesh chairs allow for airflow and are great for warmer office spaces. Care should be taken that the mesh chair can support in an upright working posture and that the lumbar support is adjustable and comfortable for the user.
Synchro Swing Motion Vs Independent tilts: Chairs generally have 2 forms of movement mechanisms, synchro/swing motion or independent tilts. An independent tilt mechanism allows the user to adjust the angle of the seat and the backrest pitch independent from each other, allowing for an infinite number of angle combinations. This mechanism is recommended by Physiotherapist’s for users with back conditions that require particular locked sitting postures. The synchro or swing mechanism means the user can swing the chair backwards and forwards when seated and can lock the chair at certain angles. When choosing a synchro mechanism, care should be taken that the swing motion is comfortable for the user, and most importantly that the chair will lock in an upright work posture that is useable and supportive – (check where the chair locks – and the angle of the seat in this position). Movement based Chairs are increasing in popularity and allow the user to move whilst seated.
Arms Vs No Arms: Generally the choice of armrests on the chair is at the user’s discretion. Some users will use the armrests for reading or to support their arms in certain postures, or to aid in transferring in and out of a chair. If you’re considering armrests make sure they are height adjustable, some armrests can also be width adjustable. Modern armrests can come with an adjustable arm pad that can slide forward and back and will often allow for sideways or angled adjustment. Being able to lock these arm pad motions is always the better option.
Remember if choosing for the workplace some corporate environments do not allow armrests on chairs. Most Physiotherapists do not recommend armrests on chairs as they can sometimes limit the movement of the chair into or under the desk, and some users will habitually lean on their armrests creating the spine to move out of alignment.
Chair Height: When selecting your chair remember to relate it to the height of the desk you are going to be using it at. You should know the height of your desk, most are around the 720mm mark but some can be higher or lower. Your chair should be adjustable to the height of the desk you are buying it for. Most chairs can have different lift heights fitted to them, if your desk is higher you may require a high lift, or if lower a low or small gas lift. If your chair cannot have a different gas lift height fitted remember that you may also be able to fit different castors to raise or lower the chair by limited amounts.
Castors: As mentioned above some chairs can have different size castors fitted, allowing for increases in height of the chair of up to 5cm. Larger castors can also be heavy duty rated and easier to roll. There are also different types of castors for different floor surfaces. Most office chairs will come with a standard carpet castor fitted for use on carpets. You can also fit soft castors for hard floor surfaces, glides which are feet that stop movement, and pressure locking or releasing castors that will lock or unlock with release or application of pressure ie sitting.
The biggest mistake I find buyers make when choosing an office chair is that they will try a chair, sit in the chair in a relaxed position, lean back, and say “this is the chair for me!” They forget that the office chairs most important function is to be comfortable and supportive in the “working position,” not a relaxed position. So remember to test the chair in your working position, which is generally upright and locked with full back contact and great lumbar support.
To sum up, the most important thing is that the chair be comfortable for you in your working posture and also the chairs relaxed mode. It should also tick all your boxes for your personal requirements and aesthetics. If you meet these objectives and follow the guidelines above
Please keep in mind that if selecting for use in a larger company, each workplace may also have OH&S guidelines or Facilities based “rules” which need to be kept in mind. ie No chairs with arms are allowed in the office, or all chairs must “aesthetically look” the same.
If you are looking for a new chair for yourself or a team member simply contact seated for a fitting or some personal advice from a seated specialist. [email protected]
Use our unique chair selector http://seated.com.au/chair-selector/
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