Standing too straight is just as bad as slouching, says Brita Forsstrom, an expert in the Alexander Technique.
Make it Easy: 'Good' posture is surprisingly effortless - we only need actively to use 14 out of 640-odd muscles for standing up. And although 'bad' posture is most often identified as slouching, standing up straight like a sergeant major, poking the chest out and tilting the head back is actually just as unhealthy. You should also watch out for leaning down on to one hip, and pulling the shoulders back, too.
Start at the Beginning: Nearly all postural problems originate from tension in the neck, caused by jutting the chin up and out. If you don't deal with this first, any other measures are just sticking plasters. Stop pulling your head back, let your head release forward and allow your entire spine to lengthen. Loosen your arms and shoulders; we are designed to use our hands in front of our body, so don't force them back.