A correctly fitted LAUMA model 105 belt should sit around the waist/lumbar area and feel snug enough to give gentle compression, but not so tight that it interferes with normal breathing, causes tingling, numbness or uncomfortable pressure. The aim is mechanical fixation of the lower back, not maximum tightness.
Use the Velcro closure to adjust the belt according to what you are doing. Many people prefer a slightly looser setting while sitting, especially during a long car trip or desk work, and a firmer setting for short periods of walking, household work, garden tasks or lifting. If the belt shifts up or folds, it may be positioned incorrectly or the size may not match your waist measurement.
Size 3 corresponds to a specific waist range, so it is worth checking the LAUMA size chart before ordering. The belt can only work properly if the elastic panels wrap evenly around the waist and apply balanced pressure to the lumbar muscles and lumbosacral area. If it is too loose, it may not stabilise the lower back well; if it is too tight, it can create discomfort and discourage correct use.
When first using the belt, test it during a short, ordinary activity rather than wearing it for many hours immediately. This makes it easier to notice whether the pressure, position and Velcro adjustment are suitable for your body and daily movement.