Some people present themselves as prim and posture perfect. Others seem like out and out slouches. And still, others seem to be able to use their bodies well—i.e., with reasonably good body mechanics—during movement and/or when striking common positions, all the while making it seem oh, so natural.

This shows up as a comfortable sinking down into the couch for up to several hours at a stretch.

But such a habit can do damage to your neck and/or back in the long run. The teens in the image above may be altering the normal and desirable lordosis in these areas by training—in a sense—the spinal curves to flatten and also by cultivating muscle tension and/or weakness.

One of the first things to do to get good posture is to know what’s going on in your spine when performing your usual activities. Take the woman in the picture above, for example. Based on her positioning, she’s missing out on an important opportunity to support her body. Instead of sitting upright on her pelvis, she’s got a criss-cross pattern going. Her weight is supported on the back of her pelvis, on her right elbow, and also on her left mid-back area. This is not very balanced and it will likely cause her to rely on muscle tension to keep the position, when, sadly, well-aligned bones would do a better job of it.

Learn how to sit with good posture with alignment and chair tips. Learn which types of exercises will help correct your posture.