If the human body regularly maintains the movement of neck contraction and shoulder shrugging, and is not able to relax the local muscles, and the symptoms will gradually worsen. Muscle contracture is the most common muscle in the hip area, but there are very few people who have contracture of the neck. The nature of this contracture is usually a spastic muscle contraction, and there is usually only a spastic contraction of one side of the neck muscles. Bilateral neck muscle contracture is very rare, but not uncommon. This disease is caused by the gradual fibrosis of muscle cells, which leads to the loss of their original elasticity and function, and the shortening of the total length of the muscle, which leads to the shrugging of the shoulders and the shrinking of the neck. There are also some people who just suddenly make the movement of neck contraction and shoulder shrugging from time to time, which is usually a habitual movement.