Promoting Posture
Dec 1, 2003 12:00 PM
Furniture and furnishings are important components of the learning environment. Selecting seating and desks that promote good posture not only has ergonomic benefits, but also results in a more attentive and comfortable student.
A recent research report looked at design features more appropriate for education environments, exploring such areas as:
The size of children and changes in their dimensions that affect school furniture sizes.
Furniture size that prevents harmful effects on children.
Features of school desks and chairs that can benefit children's physical and intellectual development.
Principles of posture and sizing, and their influence on school furniture design.
The report states that in many education institutions, cost criteria often necessitate a conventional-height chair without armrests. Lack of armrests also allows better freedom of entry and exit, and close positioning of the chair under the desk, which can provide arm support.
The following features are recommended to provide conditions most conductive to proper sitting:
For the resting, relaxed position:
A backrest with about a 15-degree inclination from the vertical position and convexly curved in the lumbar area; this encourages proper posture, and gives support for trunk load. The top of the backrest should be well-rounded.
The ability to reduce pressure when in a forward slouch position.
Space beneath the backrest allowing buttocks free clearance and permitting optimum use of the lumbar backrest.
The ability of the rear part of the seat to incline rearwards at about 5 degrees to help prevent forward slide and giving an included trunk-thigh angle of about 100 degrees.
Seat height and length set to avoid pressure under the thighs and adjoining areas with feet flat on the floor.
For the forward writing/drawing position:
The front of the seat should have a downward slope of 10 degrees to 30 degrees with a well-rounded edge to aid the downward angling of thighs when legs are tucked under the chair.
The seat should be set slightly high within the acceptable tolerance range of the user to suit the angled thigh.
Transversely:
The backrest should have a concave radius slightly flatter than the user's back.
The seat should be almost flat to allow various positions without pressure at the edges, and be wide enough to easily support the rear and surrounding buttocks.
The desk:
High enough to give knee and horizontal thigh freedom, and allow free sideway swing for easy entry/exit.
Provide a surface incline of at least 10 degrees, encouraging more upright trunk and head positions.
For additional information on the “Education Furniture Research” report, contact Norix at (800)234-4900.
NOTABLE
Time spent using chairs and desks in school varies by age:
- 5 TO 7 YEARS OLD
22 percent of the day using a chair, with an average sit time of 4.9 minutes.
- 7 TO 9 YEARS OLD
31 percent of the day using a chair, with an average sit time of 4.3 minutes.
- 9 TO 11 YEARS OLD
38 percent of the day using a chair, with an average sit time of 5.8 minutes.
- 11 TO 13 YEARS OLD
58 percent of the day using a chair, with an average sit time of 11.1 minutes.
Benefits of comfort
The benefits of sitting comfort for appropriate posture include:
Increased concentration on tasks without having to change position frequently to relieve pain or numbness.
Long-term postural practice that carries over to adult life.
