I did not realize what physical hazard I had created for myself until a plysical therapist visited by previous work station.  I did some research on how to select an office chair, and this chair was rated very high.  My husband put the chair together.  He said the instructions were clear.  It took more than 30 minutes to assemble.  It is very comfortable, has changed the way I sit.  I am a writer so I do spend much time mulling and pulling at my thoughts.  Not necessary with this chair.  We  may buy another one. great buy!.