494
Level 2
Board Level
Fig. 8a
Excessive ulnar deviation
Fig. 8b
Proper hand position on the keyboard: no wrist
deviation, resting on palm rather than wrist
Adjustable Chairs and Twisting
Chairs or stools and exam tables that are not adjustable result in
excessive reaching and trunk twisting in order to reach the patient
during an examination. Sitting in an unsupported position increases
pressure on the lumbar spinal discs 40% over the pressure from
standing. Forward flexion and rotation of the body increases the
pressure on the lumbar spinal discs by 400%
9
. These strain-inducing
positions are frequently assumed by sonographers during patient
exams or while working at computer workstations. Chairs or stools
that provide trunk support and proper spinal alignment can reduce a
worker’s exposure to injury. Adjustable chairs allow the practitioner
to comfortably reach the work area while sitting and to view the
ultrasound monitor without too much neck flexion or extension.
Additionally,ergonomic chairs promotemovement so that adequate
circulation to the muscles is maintained. Ergonomic seat design
reproduces the normal standing position in which the spine has a
natural curve. This curve should be maintained even while leaning
forward on the seat. While sitting in a conventional chair, the spine
is forced into an unnatural, flattened position.
Fig. 9a
Improper position: seated with reach and abduction
Fig. 9b
Improper position: seated with too much reach and
leaning
Fig. 9c
Proper seated position
Adjustable Ultrasound Monitor
To reduce neck strain and pain, the ultrasound monitor should be
at an appropriate height for each sonographer. To reduce excessive
neck flexion or extension, the top of monitor should be in line with
the sonographer’s sight when the neck is in a neutral position. If
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