Because as you've now read, bad posture affects almost all areas of your body in a negative way. If you're concerned about your posture and how it's affecting your health, you can see an osteopath without a referral from your GP.
Aside from easing pain, osteopaths can also help improve flexibility, and joint motion, as well as provide you with advice on the ergonomics in your environment (ie, the placement and alignment of your desk/computer/chair/). Visit Osteopathy Australia to find your nearest practising professional.
You can also look to ballet-style workouts if you want to maintain good spinal health — the popular exercise fuses Pilates, yoga and ballet and, with a strong focus on the core, assists in correcting posture.