A bony protrusion at the back of the neck is often due to several reasons: First, it may be a normal bony protrusion. At the back of the neck, there are very many bony protrusions, such as the spinous processes of the cervical vertebrae that can be felt under the skin, and these protrusions become more pronounced if the patient is thin or does head-down movements. For example, at the back of the neck, the most obvious one is the spinous process of the seventh cervical vertebra, also known as the rongeur, because when the body lowers its head, the spinous process here becomes very protruding because it is longer. Second, this condition may be caused by the misalignment of some small joints of the cervical spine, which is often seen in patients with cervical spondylosis. Such patients have some abnormal bony protrusions at the back of the neck due to the straightening of the physiological curvature of the cervical vertebrae, inversion of the arch, and misalignment of some small joints of the cervical vertebrae, which often induce very obvious pain when pressure is applied to them. Thirdly, this condition may be caused by some old injuries of the cervical spine, such as some fractures and dislocations of the cervical spine in the past, which may leave a local bony protrusion after recovery.