The term immobilization refers to the use of devices studied to reduce movements of one or more body segments in order to avoid other injuries a part from those already caused by the trauma itself.
Immobilization devices are divided into two categories: devices for partial immobilization and devices for total immobilization. Cervical collars are part of the first of these two groups. This device significantly limits patient’s neck’s movements, although alone is not sufficient to ensure complete immobilization. Cervical collars currently available on the market are mainly of two types: monovalve, formed from a single piece, and bivalve, formed by two. 
Rigid monovalve cervical collar is usually made from a single piece of plastic material provided with padding and characterized by a shaped ruff on the front and a cervical shield almost flat. Bivalve rigid cervical collar, instead, usually consists of two distinct padded plastic parts. Using this type of device, first we proceed by positioning the chin-rest, that’s the front part, and subsequently the occipital support, that’s the rear part. Both types of collars have a large central hole that allows to measure the carotid pulse, to carry out tracheotomy and to enable rescuers to set up various types of operations. Normally, non-adjustable models are available in different sizes: is crucial to correctly measure the size of the collar in order to choose the right one for patient’s anatomy to make an accurate and safe ìimmobilization.
The application of both types of these cervical collars necessarily requires the presence of two operators. Before starting the immobilizing operation, you should remove objects that could impede the proper positioning of the cervical collar (such as necklaces, big earrings, scarves and various clothing). The first rescuer, when possible, is placed behind the patient and manually immobilizes his head and neck in a neutral position. This one, in fact, ensures less risk of spinal cord injury, realising the maximum possible space within the spinal canal. The second rescuer, however, deals with the application of the collar to the patient. During these operations It is essential that the head is always held motionless and in neutral position.