Design
What is the difference between office chair mechanisms?
Office Chair mechanisms are regarded as the “heart” of an office chair.
After a long day of work, many people experience backaches and stiffness in their neck and shoulders. To address these challenges, you may have heard about ergonomic office chairs and orthopedic office chairs. However, there is often confusion between the two types of chairs. What are orthopedic office chairs and how do they differ from their ergonomic counterparts? What is the best office chair for medical conditions like sciatica?
Both ergonomic and orthopedic office chairs aim to enhance comfort and wellbeing. Ergonomic chairs are more general-purpose solutions focused on promoting good posture and preventing discomfort. Orthopedic chairs are specialised options tailored to individuals with existing orthopedic conditions.
Is there really a difference between an ergonomic and orthopedic office chair? YES!
Unfortunately, many office chair retailers use these terms interchangeably to describe their products, thereby creating confusion among consumers.
In this article, we will define both chair types and highlight their differences. Finally, we will provide guidelines to assist you in selecting the right office chair and deciding which is best for medical conditions like sciatica. The dangers of sitting: why sitting is the new smoking.
It is important to note that finding the ideal chair for your needs is only part of the solution. How you setup your chair and workstation is equally important.
What is the correct ergonomic height for my desk, computer monitor and office chair?
1. What is an ergonomic office chair?
Ergonomic office chairs help prevent back, neck and shoulder pain caused by sitting for long periods.
An ergonomic chair is a type of chair that is designed with the aim of providing optimal comfort, support, and efficiency for people who spend long periods of time sitting at a desk or workstation. The design principles of ergonomic chairs take into consideration the natural alignment of the human body, particularly the spine, to minimise strain and discomfort. These chairs are often used in office settings, but they can also be found in various other environments where extended periods of sitting are common, such as home offices, study spaces, and gaming setups. A critical aspect of any ergonomic office chair is ADJUSTABILITY – Why a fully adjustable office chair is important.
Key features of a good ergonomic chair include:
Design features of ergonomic office chairs
- Seat height adjustment.
- Backrest angle adjustment.
- Adjustable lumbar support.
- Adjustable seat depth and armrest width.
- Height adjustable armrests.
- Contoured backrest that matches the shape of your back.
- Moulded foam seat with a waterfall front edge.
- Stable base with castors.
The greater the number of ergonomic adjustability features a chair has, the higher its ergonomic rating becomes.
If you have a non-chronic back, neck or shoulder problem and you spend the majority of your day in a seated position, you should be sitting on a highly rated ergonomic office chair.
Ergonomic office chairs are usually fitted with one of the following types of swivel mechanism:
- Synchronous (or Synchro)
With this mechanism, the movement of the backrest and seat is mechanically linked, so when the backrest moves, the seat will move with it, and in the same direction.
The movement of the backrest and seat occurs in a fixed ratio, typically 2:1. In other words, for every 2 degrees of movement in the backrest, the seat will move 1 degree.
With a synchronous mechanism, you cannot adjust the backrest angle without simultaneously adjusting the seat angle. - Permanent Contact
With these mechanisms, only the angle of the backrest can be changed. The inclination of the seat remains fixed and cannot be adjusted.
2. What is an orthopedic office chair?
Orthopedic office chairs alleviate the impact of sitting on existing medical preconditions of the lower back and are recommended for anyone with chronic lower back pain.
An orthopedic chair is a specialised type of chair designed to provide support, comfort, and relief for individuals with orthopedic conditions, musculoskeletal disorders, or other physical challenges. These chairs are often prescribed or recommended by healthcare professionals to help alleviate existing back pain, promote proper posture, and improve overall comfort for people dealing with various orthopedic issues.
Orthopedic office chairs are designed to provide targeted support and comfort for individuals with existing orthopedic conditions or musculoskeletal disorders. Typical examples include chronic back pain, coccyx pain, sciatica, arthritis, and other conditions that require the specialised support provided by an orthopedic chair.
Orthopedic chairs include all of the above design features of ergonomic office chairs. These chairs will therefore also prevent back, neck and shoulder pain caused by incorrect sitting. How to Protect Your Health in the Age of the Office Chair. However, the main difference between orthopedic and ergonomic office chairs is that an orthopedic chair has a Free-Float Swivel Mechanism and an optional height adjustable backrest.
a. Free-Float or Multi-Functional Swivel Mechanism
Orthopedic chairs use a free-float swivel mechanism that allows separate, or independent control of the movement of the seat and backrest.
This is not possible on a chair fitted with either a synchronous, or permanent contact mechanism.
Unlike a synchro mechanism where the movement of the backrest and seat is mechanically linked, a Free-Float mechanism allows the seat and backrest to be adjusted independently.
By independently controlling the angles between the backrest and the seat, orthopedic office chairs may alleviate, and even rehabilitate certain medical preconditions, specifically musculoskeletal issues of the spine like sciatica. What actually happens when you sit?
The free-float mechanism on an orthopedic office chair allows the seat to be adjusted to a forward sloping position. This reduces the disc pressure in the lumbar region of the back. The forward slope, or negative tilt, is typically limited to a maximum of 5 degrees.
Medical professionals often endorse orthopedic office chairs.
b. Back Support and Height Adjustable Backrests
When choosing an office chair, one of the key factors to prioritise is adequate lumbar support for the lower back. Back support for an office chair – why it’s important.
Good back support is essential in order to prevent the onset or exacerbation of back-related health issues.
Prolonged periods of sitting on a chair without proper back support makes it difficult to maintain the elongated ‘S’ shape of the spine. This can lead to heightened pressure on the lumbar discs, resulting in discomfort and pain in the lower back area. Breaking Back – What actually happens when you sit?
Office chairs with good lumbar support play a pivotal role in ensuring that your spine retains its natural elongated ‘S’ shape.
i) Office chairs with a height adjustable back and fixed lumbar support
This type of office chair features a backrest that is height adjustable, coupled with a fixed lumbar support. The backrest is typically fully upholstered and padded. This design enables you to vertically align the chair’s backrest with your lumbar curvature, promoting better ergonomic support.
Height adjustment can be achieved through either a ratchet mechanism offering multiple preset positions, or alternatively, a handwheel that provides versatile customisation options.
In South Africa, our OrthoLux orthopedic office chair has a backrest that can be adjusted in height while maintaining a stable lumbar support.
ii) Height adjustable backrest on an office chair with an independently adjustable lumbar support
This type of office chair features a backrest that can be adjusted vertically and it also includes an independently adjustable lumbar support. This means that you can customise the vertical positioning of both the chair’s backrest and the lumbar support according to your specific needs.
The vertical adjustment feature of the backrest provides multiple height options, allowing you to select the setting that best suits your personal comfort preferences.
To ensure the utmost comfort, these office chairs are equipped with a distinct lumbar support adjustment. This feature allows you to finely calibrate the back support, further enhancing your overall sitting experience.
iii) Office chair with a height adjustable back and inflatable lumbar support
This type of office chair boasts a height-adjustable backrest and an inflatable lumbar support feature. The vertical adjustment of the backrest’s height caters to a diverse range of users.
Engineered for exceptional back support, the OrthoMax Orthopedic Chair integrates a pneumatic lumbar cushion with an internal bladder that is easily inflatable via a manual hand pump. This innovative mechanism enables precise customisation of the back support’s position and firmness, ensuring the attainment of an ideal and personalised comfort level.
The OrthoMax orthopedic chair is the preferred option for pre-existing medical conditions like sciatica and chronic back pain.
3. Ratings for Orthopedic Office Chairs
To assist you in selecting the correct orthopedic office chair, we have developed an Orthopedic Rating system. This rating is based on a 4-point scale where a point is awarded for each attribute.
BASIC. This is the entry-level rating. An orthopedic chair must have a free-float mechanism.
FAIR. An additional point is awarded for height adjustable armrests.
GOOD. A further point is awarded for multi-adjustable armrests.
EXCELLENT. The final point is for a height adjustable backrest or adjustable lumbar support.
4. Comparing Chair Types
In the table below we compare the important differences between orthopedic and ergonomic office chairs.
| Feature | Orthopedic chair | Ergonomic chair |
|---|---|---|
| Swivel and Tilt Mechanism | Fully independent free-float mechanism | Typically synchronous or permanent contact |
| Seat Foam | High-density automotive grade moulded foam | High-density automotive grade moulded foam |
| May alleviate certain medical preconditions, specifically musculoskeletal issues of the spine like sciatica | Yes | Less likely |
| Seat angle adjustment | Yes, fully independent and lockable in any position | Mechanically linked to the backrest movement or fixed for permanent contact |
| Negative tilt (forward sloping) seat adjustment | Yes, limited to 5 degrees | No |
| Backrest angle adjustment | Yes, fully independent and lockable in any position | Yes. For synchronous mechanisms, there is a mechanical link to the movement of the seat. |
| Backrest height adjustment | Preferable | Optional |
| Lumbar support | Yes, integrated with backrest | Optional on better ergonomic chairs |
| Multi-Adjustable armrests | Optional | Optional |
5. Heavy Duty Orthopedic Office Chairs
If you have a larger build and need a executive high-back chair, most standard task chairs will not be suitable for you. Furthermore, if you also have a back-related ailment, not only do you require a heavy duty office chair, but also an orthopedic one that provides the correct support for your back.
Such chairs are specifically designed to offer the vital support and features required for a truly comfortable and health-conscious sitting experience. There are very few office chairs available in South Africa that combine both the heavy duty and orthopedic attributes. A standout illustration of this is the Ortho Grande XXL Heavy Duty Orthopedic Chair which has an “EXCELLENT” orthopedic rating.
The Heathrow Heavy Duty Orthopedic Chair is equipped with a fully independent free-float mechanism but lacks a height-adjustable backrest. Nevertheless, the backrest on the Heathrow is designed to accommodate a wide range of people. For this reason, the Heathrow Heavy Duty Orthopedic Chair has a “GOOD” orthopedic rating.
6. What is the best office chair for sciatica? Is an orthopedic office chair a good choice?
Sciatica occurs when the sciatic nerve is pinched. It results in pain in the lower back, back of the thighs, and legs. Typically it only affects one leg.
The best office chairs for sciatica should have a forward tilting seat and excellent lower back support. In others words, an orthopedic office chair is ideal for a medical condition like sciatica.
7. Which chair is best for you?
Before selecting an ergonomic or orthopedic office chair, the first question that needs to be answered is whether or not you have any medical preconditions, specifically musculoskeletal issues of the spine like sciatica. If so, then it is likely that an orthopedic chair will be the better option. If not, then either chair type will be suitable.
Remember:
All office chairs are designed for the “average” person, in other words, the majority of people, but not everyone. For example, a short slim person may find that a standard chair is too high and the armrests are too far apart. In such a case, the chair may need a different height adjuster or armrests that have width adjustment.
Investing in a well-designed office chair can significantly improve your comfort and productivity while reducing the risk of musculoskeletal issues. Understanding the differences between ergonomic and orthopedic chairs will empower you to make an informed decision and select the best chair for your needs. Always prioritise your health and well-being when choosing an office chair for your workspace.
Ergonomic and orthopedic office chairs are designed for the “average” person.
There is no, and will never be, a one-size-fits-all.
To ensure you purchase an office chair that’s right for you, get guidance from a specialist
Contact us for professional advice
Selecting the right chair must take the following into consideration:
- pre-existing health (musculoskeletal) problems, specifically related to the spine.
- body size and shape.
- the task that you have to perform.
- workstation design (e.g. dentists require a different chair than industrial workers or computer operators).
- the number of hours you sit at your workstation each day.
For a detailed explanation, refer to our article – How do I choose the best office chair?
Still confused? Do you need help selecting the right chair?
Our team of qualified Office Ergonomics Risk Facilitators will assess your posture and determine whether an ergonomic or orthopedic office chair is best for you!
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