I beg to differ. The good thing of an adjustable desk is that you can set it at the perfect height both when you're standing and sitting. Many of us type on the keyboard while arms are resting on the desk. If the desk is too low the back suffers. Standard desk height is 90cm (Europe), and for me that is too low. I set it at around 96 cm when sitting.

The chair is also very important (does it help you to have a correct sitting position) and should be adjustable to have a 90 degree leg bend too. And the screen should be in front of the eyes while sitting and standing (standard feet for many computer screens raise them way too little from the 90cm desk), so you may need an extra arm.

While standing, I try to take my shoes off as shoes (even if by 1cm) usually alter the natural position of the feet on the floor and that goes up to the back too. I've also seen people stand on soft playground mats for extra comfort.

The downside of all this is the prices (good office chairs starting on 800 euro and same or more for standing desks). Hopefully your employer can provide it...

This is what I have. I just have a cheap Ikea Jerker desk. It has worked great for me for a long time. I can stand sometime, use my chair other times. I good tall-chair was the trickiest part for me to find.