"If by any chance you intend to design a chair for prolonged use, then please first readhttp://sittingsafely.com/introduction-for-designers/ Otherwise you may be just designing a 'machine for making backache'."

"The Sit/stand concept has slowed following work showing less difference in sitting and standing intra-disc pressures as was first thought.  A comeback is occurring as the importance of keeping staff exercised is recognised. See http://sittingsafely.com/sit-stand"

"As a consultant orthopaedic physician who has had to treat backache for 50 years I could not respond to my patients request for an ergonomically correct chair as none existed in the market. So, in 1998, I researched the latest spinal bio-mechanics and pathology and the logical conclusion was that the only way to avoid or limit LBP was to adopt a reclined position for prolonged work. And you are right, this must be the way things will go. To adapt this simple concept to an efficient work chair involves a number of essential requirements. The practicality was tested in the engineering (IfM) department at Cambridge and the students working on the project also came up with a deskless variant, as is yours. For essential requirements see http://sittingsafely.com You will certainly meet plenty of familiarity bias and even normalcy bias from manufacturers.   Good luck.  You will need it!"