Soreness on both sides of the back of the neck is usually caused by muscle strain, cervical spondylosis and other reasons. 1. Muscle strain: the two sides of the back of the neck usually include the small muscles of the neck and the trapezius muscle, prolonged low head work, read the cell phone, watch TV for too long can cause muscle strain leading to the back of the neck on both sides of the tendons soreness, prolonged work will easily aggravate the condition. 2. Cervical spine disease: such as cervical disc herniation, cervical spondylosis can compress the nerve to cause reflexive muscle tension in the back of the neck, can appear behind the neck on both sides of the tendon pain. The back of the neck on both sides of the tendon pain may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, give targeted treatment or standardized treatment.