If you’re reading this, chances are, you’re slouching at least a little. Even if you’re sitting in a chair you think is comfy, it probably doesn't encourage the best posture. If you really want to improve your sitting posture, you need to banish the backrest and sit on the edge of your seat, according to Jean Couch, a Palo Alto-based yoga teacher who specializes in helping people reduce their back and joint pain.

Modern chairs aren’t built for our true ergonomic needs, she argues. Our bodies were better off in the days when chairs were made of hard wood, with flat, firm surfaces that were proportional to the human body. Today’s large, cushy chairs, while they may feel comfortable to sink into after a long day, are bad for our backs. They’re probably too deep, leading us to sink back instead of sitting up straight, and too soft, causing our spines to bend.

It’s possible to correct your tendency toward poor posture without investing in a dozen antique Shaker chairs, though. Couch recommends a rather simple tweak to save your back, if you can remember to do it in the moment: You want to be on the edge of your seat.

If you sit on the hard front part of any chair, rather than using the backrest, you’ll be less likely to tuck your pelvis under your spine, bending your back into that pain-producing C shape. Rather than remaining exactly parallel with the floor, your knees should be angled below your hips—the angle should be around 120°, rather than 90°. This edge-of-your-seat, slightly forward-leaning position is actually more comfortable, and you’ll be less likely to slouch as a result.

Need proof? It’s very similar to what’s known as “neutral body posture,” a standard position developed by NASA based on measurements of astronauts floating in microgravity.

[h/t NPR]