Before selecting a back brace you will need to determine what the purpose of the back brace is and what it can do for you. When getting a medical brace to the back doctor prescribes a brace will have all this information ready when you're fitted for a brace to your back.
If you have persistent back pain you must have a brace that will help to improve your bad posture. If you participate in activities that will require heavy lifting you will want one that gives you support. Some need orthopedic spine brace that will help to support your back while you are recovering from an injury.
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For bending and heavy lifting consider lower back brace that has suspenders so that when not in use can hang from your shoulder. This will keep it from moving normally when you do not lift heavy objects. The brace should wrap tightly around the abdomen and lower back just above your hip bone.
The back of this brace must immobilize your lower back when you lift heavy objects, forcing you to lift with your legs and not your back.
Posture back brace will often support the entire back and not just your lower back. Carefully consider what materials were used to build the brace. While the latex strongly supports it does not breathe properly.