"For those who do sit down all day and don't have back problems a word of caution. Sitting all day makes your lower back very stiff, but you won't notice this u

"For those who do sit down all day and don't have back problems a word of caution. Sitting all day makes your lower back very stiff, but you won't notice this until you try to do something and hurt yourself. It may be a lifting task that an unstiff back could cope with. Taking time to exercise and stretch can save you such a disaster, I am healing well now, but still get twinges and have to be carefull." That is the right caution, but the wrong reason. A stiff lower back (lumbar) is desirable. You want to be mobile at your hips, and upper back (thoracic) and have the ability to keep the lumbar stable. When you lift something your lumbar spine should be immobile. You are correct that there are problems with sitting but it is that typically your lumbar is rounded so that you are weakening and stretching it all day long making it difficult to maintain proper posture when you lift something from the ground. A quick rule of thumb for mobility: Ankles (mobile), Knees (immobile), Hips (mobile), Lumbar (immobile) and Thoracic (mobile). Stuart McGill is a great resource for learning about proper back mechanics. Oh, BTW, I use a stand up desk and love it.