Lumbar muscle strain is actually a chronic inflammatory injury of the muscles in the lower back and their attachment points, fascia, or periosteum. It is one of the primary causes of lower back pain. As for its causes, there are generally two: the first being chronic strain; the second is improper treatment of acute lumbar trauma, which then becomes prolonged and turns into chronic lumbar muscle strain. Starting with the first cause, it mainly arises from long periods of bending over during work, putting the lumbar muscles in a constant state of tension, then leading to the compression of small blood vessels and ultimately causing insufficient oxygen supply to the muscles and poor elimination of metabolic substances, which then stimulates local inflammatory injuries. So, this is the main reason. Generally, in the early stages, the muscles are still in a compensatory adjustment phase, but as the condition progresses, they can no longer adjust, resulting in a series of compensatory adjustments, leading to lumbar muscle strain and ultimately causing back pain and restricted lumbar mobility. Thus, the primary causes of lumbar muscle strain are two-fold: the first is long-term chronic overload of the lumbar region, causing inflammation. The second is improper treatment following an acute lumbar sprain or trauma, which eventually leads to chronic lumbar muscle strain. There are essentially these two reasons.