If you find yourself tired and achy after a day of work in your home office, don't reach for a cup of coffee. Instead, look down at your office chair. People are sitting down more than ever, and having an ergonomic and comfortable chair at your desk could totally improve the way you feel after a day at the desk.

Whether you're shopping for a new task chair or examining the one you've got, here are 6 must-have features to ensure your day at the desk doesn't become a nightmare.

Adjustable Height
Depending on your desk, the optimal height for a desk chair varies, so make sure your chair offers adjustable height. A seat height that ranges from about 16 to 21 inches off the floor should work for most people. You want to be able to keep your feet flat on the floor with thighs horizontal and arms even with the height of the desk, according to spine-health.com.

A Reclining Seat Back
This ain't grade school, and you don't need to sit up in class anymore. According to the experts, sitting at a reclined 135° angle puts the least strain on your back. Make sure your backrest has a little room for slouching back in your chair.

Armrests
The reccomended arm position to reduce strain is to keep your upper arms close to vertical and your forearms close to the horizontal plane. So buy a chair with armrests and vow to use them.

A Deep Seat Depth
To keep your knees in great shape, you need a seat with the right depth for your body. Sitting with your back against the backrest, a proper seat depth should leave between 2 and 4 inches between the seat of the chair and the back of your knees.

Proper Wheels
Not all rolling chairs are created equal. If your desk is on a hard surface, find a chair with soft rubber wheels. If your workspace is carpeted or sits on top of a rug, hard wheels will help you navigate best.

Adjustable Lumbar Support
Sitting for long periods without support for your curvy lower back will strain your spine and lead you to slouch, so make sure you find a chair with lumbar support. Make sure the lumbar support is adjustable in both height and depth; you want to keep the lumbar support of the back rest in your lumbar region (around the waistband).

MORE ON HOME OFFICE CHAIRS FROM APARTMENT THERAPY:
• 5 Ways to Make Your Office Chair Suck a Little Less
• How to Pick the Perfect Home Office Task Chair
• Reasons Why Sitting Down is Killing You
• What's Wrong With Your Home Office... and How to Fix It
• The Importance of a Good Office Chair
• How to Choose Your Perfect Office Chair

(Image: Herman Miller Aeron Chair)