The purpose of wearing a weight belt is to protect the lower back. While there is debate as to whether a weight belt can actually keep a lifter’s back safe, there is no doubt that without proper exercise execution and attention paid to posture, even a weight belt will be useless.
Proper posture is integral to weight training and one of the basic things that a lifter should be striving to achieve. Poor posture often leads to poor exercise form and increasing the existing muscular imbalances, not to mention the increase in chances of injury. A simple way of maintaining good posture during lifting is to do a mental checklist before you begin every exercise.
If you are standing, make sure your feet are shoulder-width apart; the back is upright with the chest thrust out and shoulders pulled back. Hold your chin up and always keep your abdominals tight throughout the execution of the exercise.