The periapical area is the area around the shoulder joint, which serves to keep the joint stabilized, among other things. The shoulder joint is the connecting part of the upper limb and the trunk, and it is the joint with the greatest range of motion in the human body, while the periapical region mainly refers to the surrounding of the shoulder joint. The role of the periapical area is to connect the joint head and the joint fossa, and to maintain stability within the joint to avoid friction of the articular cartilage surfaces, which can help in the flexion and extension of the joint. If the ligaments and joint capsule in the periapical area are strained, it will easily lead to frozen shoulder, which will cause pain, accompanied by the limitation of shoulder lifting function, and also easily lead to dislocation of the shoulder joint. If you are not feeling well, you should go to the hospital in time to get a clear diagnosis and then the doctor will arrange a treatment plan, which should not be taken lightly to avoid delaying your condition.