The main causes of knee muscle adhesion include inflammation, trauma and tumor. 1. Inflammation: Most of the muscle adhesions are caused by inflammation, such as localized myositis, cellulitis, abscess and so on. After the inflammation heals, it will cause scar tissue which will lead to muscle adhesion. 2. Trauma: Muscle adhesion can also be caused by trauma, after trauma will cause local internal bleeding, when the bruise is absorbed, it will be mechanized into scar tissue for repair, and the scar tissue will cause muscle adhesion. 3. Tumor: muscle adhesion can also be caused by tumor, because the growth of tumor will grow and adhere to the muscle tissue, thus causing muscle adhesion. Functional exercises can be performed after knee muscle adhesion, and surgical release treatment is needed in serious cases.