Standing for 12 hours a day may lead to the following: 1. It may cause a series of fatiguing injuries. If you stand for such a long time in a day, it may lead to corresponding fatigue injuries in the lower limbs, lower back, and even the chest and back. For example, in the lower extremities, there may be degenerative lesions of the knee joint, such as osteoarthritis. In the hip, there is a risk of ischemic necrosis of the femoral head in addition to osteoarthritis. In the lumbar region, there is a risk of lumbar strain or a series of degenerative changes in the lumbar spine. In the thoracic back, it may produce muscle tension, fasciitis, or small joint misalignment.2. Prolonged standing may lead to severe swelling of the lower extremities. In the process of standing, the lower extremities are in the very lower part of the body, and blood circulation is slower, which can easily lead to swelling of the lower extremities. 3, it may lead to foot-related injuries. Long-term standing, squeezing, may lead to the collapse of the arch or produce vascular and nerve compression-related diseases in the foot. 4, long-term standing may also lead to deep vein thrombosis in the lower limbs. Long-term braking and inactivity of the lower limbs may lead to slow blood circulation and thrombosis in the large veins of the lower limbs.