When designing interfaces between people and computers, the planning of training materials and the design of human tasks, the importance of the psychological dimensions of work should not be underestimated. Varying a job role not only makes the day more interesting, but, by avoiding being in one position for an extended period of time, a beneficial effect is seen on the muscles, joints and circulation. ‘Postural fixity’ — or being static — is one of the factors in developing a deep vein thrombosis (DVT).

Blood clots

About one to three people in 1,000 in the UK develop a DVT each year. A DVT usually develops in a deep vein in the leg, but can occur elsewhere, such as the arm. A DVT is different to blood clots that form in a separate set of veins (called superficial veins) that lie under the skin. These clots are called superficial thrombophlebitis and are much less serious. When blood clots outside a blood vessel, this is a normal process, which protects the body against losing blood. If the blood clots inside a blood vessel, as with DVT, this can be dangerous.

In most cases of DVT, the clots are small and do not cause any symptoms. The body is able to gradually break down the clot and there are no long-term effects. Larger clots may partially or totally block the blood flow in the vein and cause symptoms such as swelling of the calf; this is usually different from the mild ankle swelling that many people get during long haul flights. There are a number of risk factors, including a family history of DVT, varicose veins, recent surgery or trauma to the leg, women taking the contraceptive pill and those who have recently given birth. Anyone at risk should avoid long periods of inactivity — standing or sitting. A dentist, hygienist or dental nurse who is standing still for long periods of time should try to take every opportunity to break off from what they are doing to move around as often as possible. ‘Wiggling’ the toes or circling the ankles can be done whilst standing or sitting and is a good way of encouraging venous return and avoiding the pooling of blood.

Fit for the task

Good health is more than just not being sick; the World Health Organisation definition of ‘good health’ includes, among other things, the absence of disease, good hydration, good nutrition and a feeling of wellbeing. Chiropractors deal with the diagnosis, treatment and management of musculoskeletal pain. Many patients present because they are currently experiencing pain, but pain can be an unreliable indicator of any underlying problem. Indeed, pain can be one of the last things to present in the development of a problem and one of the first things to go away.

Chiropractors use many ergonomic principles in the management of musculoskeletal pain, but there are even more significant implications for efficiency, productivity, safety and health in the workplace. Ergonomics is the study of human abilities and the characteristics which affect the design of systems and jobs, with an aim to improve efficiency, safety and wellbeing or, in simple terms, ‘fitting the task to the person’.

An ideal environment

There are some key principles that can assist the dental team in improving the work environment from an ergonomic perspective. The ideal scenario is for equipment, workspace and job to be designed around the dentist and their staff, rather than the individual having to compensate for the environment. In other words, to use the body how it was supposed to be used; if something is used for a task it was not designed to be used for, it will break (eventually).

1. Ensure equipment and systems are used correctly and comfortably

Sitting bent forward can put almost twice as much ‘discal pressure’ on the spine than standing upright. Seated dental staff, therefore, may want to use something like a ‘saddle seat’ that allows their pelvis to be rotated forward, meaning that any load on the spine is in ‘axial compression’ (straight down from head to toe). Imagine trying to break an egg by holding it end to end between the fingers; the egg is almost unbreakable, but if you turn it on its side and exert the same force, it will break with ease. If the body is in a correct position, it feels much stronger. Using equipment that has been well designed is a start, but there is still the need to make sure it continues to be used properly and to avoid falling into bad habits.

2. Organise tasks and jobs so that they are effective and take account of human needs, such as rest breaks and sensible shift patterns

It is one thing to cater for early or late appointments for patients, but staff should be suitably ‘fresh’ for their job. Having regular rest breaks scheduled into the working day can help keep everyone feeling fresh and, importantly, help fend off the potential for injury. This also has a benefit to patients; there is the tendency to make more mistakes when tired or doing too many things at once.

3. Arrange equipment to improve working posture and ease the load on the body, reducing instances of Repetitive Strain Injury or other musculoskeletal injuries

It is obvious that using heavy equipment may cause injury, but body parts should also be part of the equation. For example, holding a weight at waist height and close to the body is five times easier than holding that same weight at arm's length. Think about body position when holding suction or using a computer mouse at arm's length. It is advisable to develop optimum positions for equipment handling, so that everyone involved with using it is aware of appropriate handling techniques.

4. Information design

Giving proper thought to the use of handbooks, signs and displays is important. Consider what the stated purpose of the information is; who needs to be able to read and understand it; and if there are any factors that influence the interpretation of the information. The ‘translation’ of information is much less error-prone if proper thought is given to the design of the information. Information design is particularly significant with regards to the Disability Discrimination Act (see Vital autumn 2004).

5. Constantly review

It is taken for granted that everyone can do their jobs, but the training could have been some time ago or particular sub-optimum ‘styles’ or ‘habits’ have developed with time. A lot can be learnt by re-visiting tasks or procedures or from watching colleagues at work. If a particular task causes the same kind of problem for a number of ‘operators’, then re-designing how the task is carried out, or investigating whether there is a more suitable piece of equipment available, can help to counter the issue.

6. Design working environments, including lighting and heating, to suit the needs of the users and the tasks performed

Many of these items are included in risk assessments. Special attention should be given to personal protective equipment; if it isn't usable or is difficult to use, it is less likely to be used. Humans can adapt to unsuitable conditions, but adaptation often leads to inefficiency, errors and stress.

7. Achieving good ‘physical fit’ of the equipment used in the practice

This is no mean feat when you consider the range of human body sizes across the population. The science of anthropometrics provides data on dimensions of the human body in various postures. Biomechanics considers the operation of the muscles and limbs, and ensures that working postures are beneficial with excessive forces avoided. If more than one staff member has to use the same equipment then, when possible, this equipment should be adjustable so that each individual can make changes to suit their physical ‘coordinates’. Imagine driving a car other than your own without adjusting it to suit you; it may be difficult to drive safely, or even to drive at all. Why should equipment in the workplace be different?

8. Setting up physical parameters

This is fairly obvious, but energy requirements are often overlooked and it is advisable to look at what the physical work rate will be for the tasks at hand. Correct nutrition and hydration is essential. It is also important to look at whether the physical environment is controlled, for example temperature, lighting and noise vibration.

It is advisable to take the time to examine all aspects of the human interface to tasks in the working environment, to look at all the potential risk factors and, importantly, any aspects that can be improved, altered, or need regular monitoring. Instead of trying to accommodate to an awkward physical environment, it is far, far better to find ways of adapting the environment to suit the task and the person.

For further information visit: www.chiropractic-uk.co.uk

Many thanks to the dental team at Aspen Dental Care in Tunbridge Wells who kindly put their appointments on hold so that the Vital team could take photographs for this issue.