The signal of left infrahumeral ligament is not uniform, considering ligament injury or rupture, which is an important cause of shoulder instability, and may be accompanied by local redness, swelling, heat and pain, and it is necessary to clarify the severity of the injury. 1. Mild ligament injury: the ligament is not ruptured, there may be local inflammation and edema, MRI shows high brightness or mottled signal shadow. Local hot compress, massage, or with the use of blood circulation, anti-inflammatory pain medications, such as Yunnan Baiyao, Wuzui Snake Bone Paste, blood circulation pain capsule, ibuprofen and so on. 2. Moderate ligament injury: the ligament shows partial rupture, and MRI also shows high brightness or mottled signal shadow. Some patients can consider the above conservative treatment, local braking, appropriate rehabilitation exercises to promote its recovery. 3. Severe ligament injury: complete rupture of the ligament or localized diffuse swelling, MRI shows rupture or extensive high brightness signal shadow. Severe ligament injury or rupture can be considered arthroscopic surgical repair or reconstruction treatment. Ligament signal unevenness on MRI should be actively carried out for further examination to clarify the cause of the disease and choose the treatment plan under the guidance of the doctor.