Several researchers believe that back belts may lead to muscle weakness because they transfer the load from the back to the abdomen, pelvis, and legs.
Studies have shown that when a back belt is in place, the electrical activity of the back muscles is decreased. This means the muscles are not active or contracting. Over time, this can have a "detraining" effect on the muscles of the back. Once the belt is no longer used, the injury rate goes up. More research is needed to confirm this theory.