Knee pain caused by too much walking is mainly due to damage to the tissues within the knee joint. First of all, too much walking can damage the synovial membrane in the knee joint and form synovitis. Once synovitis is formed, it can lead to knee pain and an increase in the amount of fluid in the knee joint. Second, too much walking can also lead to damage to the cartilage in the knee joint. The cartilage in the knee joint is a non-renewable tissue, and once damaged, it can lead to knee pain. As the damage increases, so does the pain level. Finally, too much walking can lead to damage to the meniscus of the knee, and once the meniscus is damaged, it will inevitably lead to pain.