The causes of back muscle soreness are muscle injury, back fasciitis, osteoporosis and so on. 1. Muscle injury: trauma, prolonged exercise or prolonged labor can lead to injury to the muscles of the back, intermuscular small blood vessel injury, local oozing, edema, acidic metabolite accumulation, and local muscle soreness. 2. Fasciitis of the back: prolonged maintenance of posture, prolonged fatigue, work at home, and so on. This can cause excessive stress on the muscles and fascia of the back, and if it gets cold, it will trigger muscle spasms, which will lead to recurrent episodes over time, causing back fasciitis and localized aches and pains. 3. Osteoporosis: middle-aged and old-aged women, especially menopausal women, are prone to calcium loss, triggering osteoporosis, local bone brittle, the muscles need to bear more power, back to the soreness. Sore back muscles are recommended to be treated under the guidance of a physician.