NuChairs are quite different than the conventional chairs you're used to. You're actually strengthening your postural muscles while sitting, leading to more comfortable sitting, and even better posture when not sitting. So initially you may experience some pains in the muscles of your back and/or shoulders. But don't worry, your muscles will adjust to your new sitting posture.
If so, reduce your sitting time in your NuChair to shorter periods, maybe 30 minutes to an hour. Then take a standing break, or turn your NuChair around and use it like a conventional
chair (you can also switch back to your old chair/stool) for 10-15 minutes. Over a period of one to two weeks, you can gradually extend your NuChair sitting time till you adapt to the new sitting posture.
You also can use NuChair's adjustments to help. Don't hesitate to contact us by email at info@nuchair.com to set up a one-on-one video session where we can provide training for using and adjusting your NuChair, for optimal comfort. If you haven't done so yet, watch this short
YouTube video about Using Your NuChair . It provides many helpful instructions on how to properly use your NuChair, including "sitting behind the pommel".
If you're leaning forward too much, or looking down at your computer screen, you're not in a good ergonomic position. This can result in neck pain. Try sitting in your NuChair with the front support removed, this will get you to find your natural balanced posture you have when standing. And raise your monitor up to eye level. If you work for hours on a laptop you should have a second monitor that sits at your eye level. You should do this no matter what chair you use.