Allied Posture

Seating Guide

Introduction

The Back Pain Problem

Back pain is very common.

Almost half the UK adult population report lower back pain lasting for at least 24 hours, at some time in the year.

Inactivity and the wrong sort of movement are usually at the root of ‘simple back pain’.

This makes the muscles slacken, and become unable to support the back properly which in turn means it is more vulnerable to damage when certain movements pull too much on one area of your back.

The Costs of Back Pain

  • The estimated health care costs for back pain total £1.6 billion per year (NHS & Private)
  • In addition, the Health and Safety Executive estimates that musculoskeletal disorders, which includes back pain costs UK employers between £590 million and £624 million per year

The Impact of Back Pain

  • Every year, nearly 5 million working days are lost as a result of back pain. This means that on any one day 1% of the working population is on sickness leave due to a back problem
  • Back pain is one of the major reasons for long term sickness in much of the UK

The Real Issue

So why has back pain become such an issue? The critical reason is the revolution in working lifestyle: sitting in front of a computer is common place. Hence why a correctly designed office chair is so important. As more and more time is spent sitting at a desk, working at computers, it’s critical for an office chair to fit the employee’s body.

Ergonomic Office Chairs & Seating

Ergonomics

Good Working Posture

Use the following guidelines to maintain healthy work posture.

Sit

1. Raise or lower your seat so your thighs are parallel to the floor and your feet are flat on the floor or a footrest.

2. Adjust the depth of your seat pan so you have at least 2” of clearance between the back of your knees and the front of the seat.

3. Adjust the height of your backrest so it fits comfortably on the small of your back.

4. Adjust your chair’s recline tension—if necessary—to support varying degrees of recline. Avoid using recline locks.

5. Lean back and relax in your chair to allow the backrest to provide full support for your upper body.

Type

6. Position your keyboard support 1 – 1.5” above your thighs and angle the keyboard so it slopes slightly away from your body. Be sure to keep your wrists in a straight, neutral posture while typing, and rest the heels of your palms—not your wrists—on a palm support.

Mouse

7. Position your mouse close to the keyboard—preferably on a mousing platform—to minimize reaching. Avoid anchoring your wrist on the desk. Instead, glide the heel of your palm over the mousing surface and use your entire arm to mouse.

View

8. Position your monitor at least an arm’s length away with the top line of text at or just below eye level. Tilt the monitor away from you slightly, so your line of sight is perpendicular to the monitor.

Illuminate

9. Position your task light to the side opposite your writing hand. Shine it on paper documents but away from your monitor to reduce glare.

Align

10. Align your monitor and the spacebar of your keyboard with the midline of your body. Arrange frequently used work materials within easy reach to minimize twisting and reaching.

Rest

11. Take two or three 30- to 60-second breaks each hour to allow your body to recover from periods of repetitive stress.

Choosing a Chair

Ergonomic Chairs

Choosing the right ergonomic chair for your office can be a daunting task. We have put together the following advice to help you choose the office chair that’s right for you the individual.

1. You get what you pay for. This is true when it comes to many purchases and it is particularly when choosing office seating. Generally the more you spend, the better the chair, both in quality and in its functionality. This makes for a more comfortable experience and improved workplace wellbeing.

2. All chairs are NOT made equal. Although they may look similar all chairs are not made the same or in the same way. The quality of production will affect the quality of the end product. Look for signs of manufacturing quality such as warranty awards or ISO certificates. Does the company marketing it actually manufacture the product?

3. Suit the chair to the task. If you have a particular job or task there is probably a seat specifically designed for that. For example there are specific chairs for 24 hour usage or if you are a dentist there is also a specific range of chairs for you. If you’re daily tasks vary from the typical standards, don’t just accept a standard chair- check with your supplier for options.

4. Use the chairs correctly. To get most out of your ergonomic chair you need to use it correctly. This refers to adjusting it correctly in the first instance but also using it correctly during your daily work. Slight adjustments to your settings can have a major impact on your comfort and your chairs performance. Most of our dealers offer installation and training when you buy a chair so be sure to check beforehand.

5. One size can fit all. Well not quite, but it is possible to get a chair that fits many sizes. These chairs will have a lot of flexibility and adjustably. They can be adapted to suit a wide variety of workers or employees. However if you require a particularly large or small chair you may need to look into special options.

Features of a good Ergonomic Chair

The makings of a good Ergonomic Chair

There are certain features that are essential to make a good ergonomic chair. Then there are a number of other features, which although not essential do increase the overall performance of the chair. It is these additional features that usually separate the good from the great when it comes to office seating.

Does the chair have a good range of seat height adjustability?
As all users are different the seat height of your chair must be adjustable. Ensure that you adjust the height so that your hips are slightly above your knees, that way creating an open angle helping blood flow and the digestive system.

Is it comfortable?
It sounds obvious but all ergonomic seating should feel comfortable. Once you have adjusted the chair to your personal taste and requirements the chair should feel comfortable to sit in. Make sure that you always familiarize yourself with the adjustments by reading the instructions.

Can you adjust the backrest?
The backrest is one of the most important parts of the chair. You need to ensure it fits your back correctly and your lower back gets supported by the lumbar support. To achieve this you will need a chair with and adjustable backrest. Good ergonomic chairs feature an independent back angle option.

Does the chair allow for active sitting?
The importance of active sitting in the workplace has been well documented. It improves oxygen flow, posture and circulation all of which increase comfort and workplace performance. Sitting is by nature sedentary, so the more you work in an active position the better it is for your wellbeing.

Does your ergonomic seating support you in different positions?
When sitting “actively” its important that the chair supports you in different positions. So when choosing an ergonomic chair, ensure it supports you when you lean forward or sit back into the chair. A good ergonomic chair will enable you to sit with a forward tilt or reclined while fully supported.

Does the chair allow for armrests and neck rests?
Although these may be an optional extra the chair should have facility to allow for neck rests and armrests. Both of these provide support when sitting at a desk for long hours and can help to reduce the strain on shoulders and other parts of the body.

Does the Chair have replaceable seat and back pads?
Ergonomic chairs should allow for active sitting. They should also last a long time. While most chairs should have a reasonable life cycle it often happens that an individual part can break in daily usage or that the fabric wears out. With RH you can simply change the upholstery pad saving time, money and the planet.

Chairs Adjustments

Why do ergonomic chairs have so many adjustments?

No two bodies are the same, even ones that are the same height. We have different thigh and shin lengths, deep/shallow lumbar curves, long/short spines etc. You then have to account for genetics, working habits and injuries etc.

Ergonomic chair manufacturers accommodate this by offering a wide variety of adjustments, but what do they all do and why?

Chair Tilt


Chair recline tilt

Allows the whole chair to tilt relative to the floor.

Ergonomic Chairs recline to reduce the pressure on disks and muscles, allowing you to relax and reduce the strain on your back.

There are two types of tilt; one that pivots from the central point under the seat, your feet will come off the floor as you recline. The other is a knee tilt where the pivot is closer behind the knees, foot lift is negligible and your back and head will descend more than a central pivot. This allows movement without losing support.
Seat angle tilt adjustment

Allows the seat to tilt forward to rotate the pelvis.

When you stand up your pelvis rotates forward. This posture produces the least amount of stress on muscles, tendons and discs whilst upright. It also pulls the chest out, increases lung capacity and facilitates breathing as well as improving the working of the heart and blood circulation. Furthermore it allows you an open abdomen, which aids digestion.

When your pelvis is tilted forward your lumbar spine curves naturally and the rest of your spine follows.

This posture should be adopted when working upright or forward. The backward seat tilt can be used in conjunction with the backrest tilt to relax the spine and take some pressure off disks and muscles.

Seat

Height adjustable seat

Allows you to adjust the chair so that feet are firmly on the floor or footrest.

Also ensures that keyboard/work surface are at an appropriate height.

In a perfect world you should be able to achieve both without a footrest. A height adjustable desk may be part of this ideal solution.
Seat depth adjustment

Allows you to adjust the seat depth by moving the seat or backrest in and out.


When seated you need to be fully supported by the backrest.

If you are short in the thigh you will need to reduce the seat depth so that you can reach the backrest and reduce pressure on the back of your thighs. Shorter people often perch on the front of the seat, getting no support from the backrest, compromising their natural posture and causing their muscles to overwork.

If you are long in the thigh, seat depth adjustment will allow you to support your thighs correctly.

Backrest

Backrest angle adjustment

Changes the angle of the backrest relative to the seat.


Reclining the backrest whilst not working forward (keying or writing) allows the backrest to take some of the weight of your upper body. This in turn reduces the pressure on disks and muscles.

Armrests

Height adjustable armrests

Allows the vertical height of the armrests to be adjusted.


Supports the weight of your arms, removing the muscle work for shoulders and upper arms.

Armrests can be of particular benefit for support when keying or mousing. However, if they are not adjustable they can cause problems when armrests hit the edges of tables, causing users to key/mouse with a straight arm or perch on the front of the chair receiving no back support.
Width adjustable armrests

Allows you to position the armrest the correct distance from your body.


Armrests that are close to the body can help avoid splayed elbows, which in turn cause the wrists to bend to the side during activities such as keying.
Padded armrests


Avoid uncomfortable pressure on the undersides of the forearms and elbows

Lumbar

Lumbar support

Gentle curves in the backrest shape or inserts into the body of the backrest.

Lumbar support is intended to avoid flattening of the lumbar spine that can occur when seated, and is used best in conjunction with a tilting seat.
Lumbar pump depth adjustment

Allows the depth and sometimes the firmness of the lumbar support curve to be adjusted.


This best accommodates different preferences and body shapes.
Lumbar height adjustment

Changes the height of the lumbar support area of the chair backrest.


This feature accommodates preferences by different workers regarding where the lumbar support curve contacts the back.

Headrest

Headrest height

Changes the height of the headrest to provide ergonomic support.


Particularly helpful for people with neck and shoulder problems, and they allow the muscles in this area to relax, thereby increasing the blood flow.

The ergonomic chair headrest is normally only used when slightly reclined.


Taking The Right Measures

Your measurements

In order to supply the right chair for each individual user, the correct measurements must be taken.
Use the diagrams and guidelines illustrated below to specify the correct type of chair. All measurements are in mm and should be taken with the person in a seated postilion. A chair that promotes an upright back posture while working at the desk is encouraged.

Taking User Measurements

A

Seat Width

This measurement is taken from the width of the hips at the widest point. It may be easier to measure the person sat on a chair without arms.

B

Seat Height

Measure from the back of the person's knees to the floor. Make sure the user is in a seated position and the feet are flat on the floor. Ensure their typical footwear is considered.

C

Seat Depth

Taken from the back of the buttock to the back of the knee. NB. All Posture Collection chairs are standard with a seat slide that offers an additional 50mm of depth.

D

Backrest Height

Whilst sitting upright, measure from the top of the seat pad to the top of the shoulder (the bony prominence at the outer edge of the shoulder). A headrest option for additional support is also available on selected models.

E

Backrest Width

Sitting upright, measure across the back at the widest point.

Other Important Measurements

F

Armrest Height

This measurement is taken from the top of the seat pad to the underside of the elbow ensuring their shoulders are relaxed. This will help determine whether the benefit of adjustable arms is required.

G

Armrest Width

Measured from the inside of the arm pads in both standard and widest positions. A person exceeding the width of this dimension will not require adjustable arms.

Workstation Height/Thickness

Measure the height from the desk surface to the floor. NB. Also measure the thickness of the desk and any obstructions. This will help identify what gas height the chair will require.