** About ergonomics

THE MOST COMMON PATHOLOGIES

* Repetitive Strain Injuries (RSI) : waking up at night with itches in hands, not being able to use a screwdriver anymore, having difficulty in brushing our hair, feeling frequent dullnesses … These pains can be the sign of a repetitive strain injury. RSI are annoying, painful and sometimes invalidating, at work and even doing daily errands.

RSI include a large number of wounds and disorders of muscles, tendons, nerves, etc.:
. Back (dorsalgia, slipped disk)
. Wrist (carpal tunnel syndrome, shoulder, arm, elbow, hand
. Twist and sprain

* Chronic pains can have repercussions felt on a psychological, social and economic levels even with the family.

* Stress and anxiety, often leading to depression.

RISK FACTORS

* Static and binding postures
Posture is another name given to the position of parts of the body during an activity.

When we speak about static or binding postures, it is important to take into account :
. The number of times when a binding posture is used during given period.
. The duration during which we have to maintain a specific posture (static posture).
. The exerted strength while a binding posture is adopted.

* Bio-mechanical factors : the "repetitiveness" of gestures and excessive efforts
When we speak about repetitive tasks, it is important to take into account the repetitiveness of the task, but also :
. The duration during which the workers do the task.
. The required posture.
. The quantity of exerted strength.

* Psychosocial factors
Stress, malaise, worry, lack of autonomy, requirement level …etc should all be considered very seriously.

It is essential to know well the characteristics of the potential user.
These can have a big influence. It is always necessary to take into account the following factors:
. Physical dimensions
. Size
. Sex
. Left-handed or right-handed

* The environment

Numerous aspects of the environment must also be taken into account:
. The arrangement or the place of the existing furniture.
. The available space and the dimensions.
. Light sources, more particularly lamps.
. The type, the size of computers used as well as the place of accessories.

* Postures

There is no single recommended posture when we sit down. Here are some general recommendations:
. Shoulders are relaxed.
. Elbows are near the body.
. Move closer the chin of the breast and not bend when we look downward or forwards.
. Change position frequently.
. Alternate crossing legs.
. Avoid bending on the side.
. Avoid bending forwards.
. Do not collapse on the office.
. Don't remain seated more than 50 consecutive minutes.