Lumbar muscle strain, also known as functional back pain, chronic lumbar injury, and lumbar-gluteal fasciitis, etc., is actually chronic inflammation of the lumbar muscles and their attachment points, such as the fascia or periosteum. It is one of the most common causes of back pain. The main symptoms include swelling and soreness in the lumbar and sacral regions, recurring pain, which is often related to the weather, such as feeling cold. Factors such as daytime fatigue can aggravate it, rest can alleviate it, and the intensity of pain can vary. Sometimes, it is severe and other times it is mild. For instance, some people feel stiff as a board in the morning upon waking up and are afraid to move; this is a typical manifestation. Physical examination can confirm the condition, and some diagnostic tests like lumbar disc CT or MRI can help differentiate if there is any lumbar disc herniation. Additionally, it is also important to distinguish from conditions like piriformis syndrome, which generally involves sciatica, and symptoms like numbness and pain in the lower limbs. Once diagnosed, the first step is strict bed rest, and appropriate blood-activating and pain-relieving medication can be administered. Local heat application, massage, and electrotherapy are some of the physical treatments available. It is advisable to avoid lifting or moving heavy objects routinely, as these activities can impose significant strain on the back and are not conducive to the recovery from back ailments.