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This presentation is a summary of the workshop given at the 5th Innovative Seating conference 2010 in Frankfurt. It concerns observing postures, facilitating various positions and ways to study comfort in seats
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this workshop:
1. observe (assignment)2. global design (loungechair)3. variation while seated (4 possibilities)4. methods to test comfort (assignment)5. iterative test-design (truckseat)6. small asians and tall dutch7. priming, expectations and experience
Observe assignment
Observe these slides of people sitting - with a hand held device:Neck: bended, Arms: supported-Sitting relaxed:Legs: stretched, Legs and arms: supported-Sitting watching:Back: supported, Neck: upright, Arms: supported
comfort
no discomfort
discomfort
history (reference)+state (soft factors)
visual input noise smelltemperature/ humiditypressureposture/ movement (Vink, 2005)
but what is ideal according to users?
lounge chairs are everywhere
seats should support many postures
-people do not sit in one position
-humans do vary their postures
1777 Ramazini
2001 Dieen
(experiment)
2004 Lueder
(review scientific lit.)
static postures are hazardous
dynamic sitting increased body length significantly more than static sitting
constrained sitting is uncomfortable, contributes to chronic disorders, muscle pain, impaired circulation etc
feet off the ground!!
observed while lounging at home watching a screen (Rosmalen et al., 2010)
much variation in posture watching TV
additional movements
observed while lounging at home watching a screen (Rosmalen et al., 2010)
Kroemer et al., 2001
seat profile indicated by spine curve
20-30º
20-30º
ideal pressure
distribution for car seat
also for aircraft?
(Zenk, 2008)
much more-shear forces
-free shoulder space
-lines in the cushion
-foam characteristics
-activity specific guidelines
-electronics in seats
-……
this + 3 experiments
= input for the design of a lounge chair
(Rosmalen et al., 2009)
-obervation at home - feet off the ground
-comfort experiment – 130o
-probes
• LPD 10 subject 36 minutes in each condition • B best back rest• C better because of head rest
experiment
probes
• stimulate different sitting positions with one chair• variable armrests • feet off the ground• support the body, where needed • backrest 130o, seat 10o • head support • stuff space
Design Van Rosmalen
design criteria
the seat
of course the comfort of the chair was high,specific comments of 13 end users:
height arm height back seat head support support depth support
too high: 2x too high: 0x too deep: 1x too far forw: 2xgood: 11x good: 9x good: 10x good: 2xtoo low: 0x too low: 4x too short: 2x too far backw:4x
effects
This workshop:
1. observe (assignment)2. global design (loungechair)3. variation while seated (4 possibilities)4. methods to test comfort (assignment)5. iterative test-design (truckseat)6. small asians and tall dutch7. priming, expectations and experience
movement (synchro/dynamic) influences body length
(Dieën, 2002; Vink & Commissaris, 2005)
static chair syn chair dyn chair
static synchro dynchair chair chair
Body length increas
Sign*
1. movement in the chair
2. feet movement
3. several pillows
4. massage
Lumbar disc pressure (Pascal) according to Franz et al. (2010)
Ideas for movement?
Rotating seat
Seat pan dynamics
Stimuli to move (vibration/tickling)
Breaks for walking
Exercise stimuli in seat
etc
This workshop:
1. observe (assignment)2. global design (loungechair)3. variation while seated (4 possibilities)4. methods to test comfort (assignment)5. iterative test-design (truck seat)6. small asians and tall dutch7. priming, expectations and experience
Looze et al. 2003:
Most evidence relationship discomfort-pressure distribution and posture
EMG is sometimes related to comfort (Kuijt-Evers, 2005)
Comfort good to measure by questionnaire (Vink, 2005), e.g. LPD
Pressure distribution
Discomfort LPD measurement
Preventing neck/back complaints3 year follow up (Hamberg et al., 2008):Peak LPD (>2, scale 0-10):
RR 1,79 low back pain (n=865)RR 2,56 neck pain (n=1001)
Cumulative LPD (sum>3 of 6 measurements/day)RR 2,35 neck pain (n=2342)
Discomfort important for
This workshop:
1. observe (assignment)2. global design (loungechair)3. variation while seated (4 possibilities)4. methods to test comfort (assignment)5. iterative test-design (truck seat)6. small asians and tall dutch7. priming, expectations and experience
2nd truck seat activities observed
Relaxing readingsleepmusictelevision/games
Work laptopEating drinking/eating
cooking
design + ideas tested
1 Watching a screen above the front window feet on the dashboard
2 Watching a screen partly rotated with the screen in the right angle
3 Watching a screen above the driver door sitting 90 degrees rotated
Truck drivers prefer 3
ideal position tv watching
Test 20 subjects 10 min various postures (Knijnenburg, 2003)
Comfortable back rest angle 100-130o
Seat angle 90-110o
Knee angle 130-155o
This workshop:
1. observe (assignment)2. global design (loungechair)3. variation while seated (4 possibilities)4. methods to test comfort (assignment)5. iterative test-design (truck seat)6. small asians and tall dutch7. priming, expectations and experience
should fit: anthropometry
most international human dimensions: www.dined.nl
306-398mm
USA female: p5-p95
366-455mm
• RET wants new tram:• Good for fat and
small tram drivers• No back complaints• High comfort• Safe (1 m high object
should be seen 1 m close to the tram)
tram cabin design
Management + end-users + Bombardier (designer + manufacturer) + ergonomists
Adapt existing design
Including several end-user tests with mock-up
Main problem: small asian drivers and fat large Dutch
approach
adaptations for small Asian woman and large Dutch man.
height adjustable pedals
less complaints, more possibilities to look for new drivers
results:
This workshop:
1. observe (assignment)2. global design (loungechair)3. variation while seated (4 possibilities)4. methods to test comfort (assignment)5. iterative test-design (truck seat)6. small asians and tall dutch7. priming, expectations and experience
be aware of expectations and history
1. flying comfort correlated highest with comfort before the flight (r=.41, Konieczny, 2001)
2. business class and economy had no significant different comfort rating (Blok et al., 2008)
first sight should be comfortable
brown chair was seen as less comfortable, even while seated (Kuijt-Evers, 2001)
Bubb (2008) described similar result in car seats
first sight reaction can be measured by questioning, face reader or EMG of m.zygomaticus. Important as more sales is done by visual impression (internet)
emocard experiment now
First define what emotions you want by seeing an office chair
This workshop:
1. observe (assignment)2. global design (loungechair)3. variation while seated (4 possibilities)4. methods to test comfort (assignment)5. iterative test-design (truck seat)6. small asians and tall dutch7. priming, expectations and experience
examination (1)
People using a hand held device have their neck mostly forward bendedA. yes B. no
The next of the two postures has the highest lumbar disk pressure according to Wilke (1999) A. standing B. sitting with the back rest backwards
examination (2)
The longest observed duration in one position watching TV in the Rosmalen study wasA. 30 minutes B. 50 minutes
Dynamics in the office seat compared with a static seat resulted in A. increased body length B. Less reduction of body length
examination (3)
The most valid objective measurement related to discomfort is according to Looze, 2003
A.EMG B. Pressure distribution
According to Knijnenburg truck drivers prefer for the passenger seat a back angle of
A. 100-130 degrees B. 90-110 degrees
examination (4)
The color of the seat influences A. Short term comfort B. Long term comfort
This workshop was presented by A. Bart Koenamaosiros B. Peter Vink
More information
• Vink P, Looze MP de. Crucial elements for designing comfort. In: Schifferstein NJ, Hekkert P, Eds. Product experience. Amsterdam: Elsevier, 2008:441-459.
• Vink P, ed. Comfort and Design: Principles and Good Practice. Boca Raton (etc.): CRC Press, 2005