There are many reasons for knee soreness, such as osteoarthritis, meniscus injury, joint strain and so on. 1. Osteoarthritis: Osteoarthritis occurs in middle-aged and old people, due to the ageing of the knee degenerative changes, the formation of aseptic inflammation, so it shows the symptoms of knee soreness, pain, limited activities, stiffness, deformity and so on. 2. Meniscus injury: meniscus injury may be caused by excessive activity, trauma and other factors, which will not only lead to the phenomenon of knee soreness, but also have obvious limitation of activities, unable to twist the knee. 3. Joint strain: too much exercise in general can also lead to knee soreness, such as running, climbing, walking for a long time, etc., which can cause joint strain and induce synovitis, so there will be symptoms of knee soreness and pain. There are many reasons for knee soreness, besides the above factors, osteophytes, chondromalacia patella, excessive exercise, rheumatoid arthritis and other diseases may also cause knee soreness. It is recommended to go to the hospital in time to improve the examination after the symptoms appear, clear diagnosis, give targeted treatment, do not ignore the symptoms, take it lightly.