”It is a common condition characterized by shoulder joint pain and limited mobility. In clinical practice, rotator cuff injury and frozen shoulder both have symptoms of shoulder pain, but the treatment and exercises are very different. So, how to distinguish between frozen shoulder or rotator cuff injury? Frozen shoulder is usually caused by cold or strain, while rotator cuff injury is caused by trauma and has a different etiology. The biggest difference between the two is that the former will gradually relieve the pain over a period of six months to a year, and the arm cannot be lifted with the help of others, while the latter cannot lift the arm by itself, but it can be lifted with the help of others. Patients with frozen shoulder need to do exercises such as pushing, climbing wall lifting, and wide range of circular rotation to pull apart the adhered tissues, while exercise and activities in patients with rotator cuff injury will increase the degree of rotator cuff tear. Long time misdiagnosis will lead to fattening of the rotator cuff muscles due to lack of stress, and at this time, even if they receive surgical stitches, the treatment will not be very effective because the muscles no longer have contraction function. The most effective way to treat rotator cuff tears is surgery. The treatment technique of shoulder arthroscopy has improved the precision of surgery from technology, which not only reduces the patient’s pain and trauma, but also greatly improves the prognosis of recovery. At the same time, with the post-operative exercises, the patient’s recovery effect is also very significant. Although the symptoms of rotator cuff injury and frozen shoulder are similar, the treatment methods are completely different, so it is best for the public to find a specialist to identify the symptoms of shoulder pain to avoid delaying the best treatment time.