Testing out Constructibility of Design

Modeling in Rhino

Structure made of sanded ply wood covered in heat molded acrylic for Sheer stability and provides a continuos seating surface.  Seat back and Seat bottom connected using finger joints (waffle construction)

The Curvature and relationships of seat back to seat surface will be controlled with a definition made in grasshopper.  

Design Sketchs

Making progress.  Our posture research, store visits, along with completing several grasshopper tutorials has allowed us to move into schematic design phase.  Below are some sketches from both Max and I looking a what chair "language" and "style" would be most appropriate for using the CnC, sheet materials, and a parametric definition to execute.

Research sketches ( Posture and Qualities inherent of Chairs)

Research Sketches (Ideal proportions)

Sketches: Studies of techtonics

Sketches: Charette with Prof. Nancy Cheng

Sketches: Schematic Design.

A Visit to The Store

Max and I decided the best way to get a base line for our first chair iteration would be to sit in some chairs. We visited "Hive" and "Design within Reach"on Wednesday, two Downtown Portland Chair suppliers,  to get an Idea of what qualities a comfy chair should posses.  Below are some shots of the chairs we sat in (Max pictured).

Eames Chair: Seated all the way back felt ok

Eames molded Wood: Seated in a slouch position felt better

Eames Executive Aluminum Series:  Very Comfortable, Pivoting allows user to find best angle for back

Tom Vac Chair:  Low seat back made user feel like the might fall  out of chair

Unknown At this time: Very Comfortable, Angle between seat and seat back ideal.

Unknown at this time: Seat back height is at center of back (uncomfortable) construction, plastic,  felt weak.

Eames plastic rocker:  Seat height too low to find comfort via rocking back.  May have been more comfortable for shorter person.

Eames plastic: Comfortable when Slouched

Our trip to these stores made us aware of how finding comfort in a chair can be aided by a natural flexibility inherent in the construction materials.  Also the chair's ability to rock or slightly pivot can also help the user achieve comfort more easily.  Location of seat back height can prove negative if it falls at the center part of the seated persons back.  Chairs with higher seat backs gave user more confidence towards its integrity.   

Our trip also gave insight that owning any of these chairs in the near future is certainly out of the question.  A Barcelona lounger (not pictured) runs $4,500.  

First Investigation of Posture

We begin our quest of ergonomic response by asking the question:  What is Ideal Posture”.  It didn’t take long to find that this topic has a wide range of opinions.  A study at the University of Queensland asked participants to replicate four postures that were ideal for relieving strain on our lower backs while seated. When the individuals attempted to replicate these postures they were unsuccessful. This study speculates that we are incapable a sitting correctly and that it is something that has to be learned.  This brings up the question; can a chair promote proper posture through its design?

Other research shows that poor posture commonly referred to as slouching is not as bad as we may think.  This tendency to lean forward and adjust pressure to our lower tailbone and upper back is in response to the discomfort created from sitting at a ninety degree angle.  Levent Caglar from the charity BackCare had to say,

“As to what is the best angle between thigh and torso when seated, reclining at 135 degrees can make sitting more difficult as there is a tendency to slide off the seat: 120 degrees or less may be better.”

New concepts in seating suggest that the best and natural position for our spines to be at in is found when we are standing.  Chairs that provide support in a standing position keep the spine up right and evenly distributed pressure on our discs. This is known as (Lordosis), conversely Kyphosis refers to uneven pressure on our discs.

Lastly, in chapter 3 of Galen Cranz book, The Chair, she describes an “inherent instability” that is a result of poor sitting habits of western civilizations.  We start by sitting with our backs all the way in the chair.  This posture begins to fail as downward pressure in our hips redirects us into slouching position.  Slouching proves to be even more uncomfortable, leaving our lungs felt congested and our ribs digging into our stomachs.  We relieve this discomfort by correct our slouching only to find that we are now sitting without any back support, and thus move back to the original seated position.

These first investigation have made me aware of:

Seating Angle (ranges from 100-135 Degrees)

Importance of feet being flat on the ground while seated

Impossible to expect Humans to sit in same position for long periods of time

Correct posture may not be achievable through seating alone