Cervical collars are generally divided into two groups: soft cervical collar and rigid cervical collars. Routinely, soft collars are prescribed for whiplash injury; however, some studies have suggested the use of rigid collars

The primary function of cervical collars is to immobilize the cervical spine.

Cervical collars are typically used for an extended period of time, and they should immobilize the head and neck movement while allowing for normal daily activities. Rigid collars provide more immobilization in the sagittal and transverse planes compared with soft collars. However, some studies have shown that soft and rigid collars both provide the same range of motion (ROM) in the frontal plane. Another study using a goniometer showed that the cervical column is limited more by rigid collars than by soft ones in all planes. Patient comfort is a critical factor, which encourages caregivers to give preference to soft collars in prescriptions.

The rigid collars are a similar design to the soft collars, but are constructed out of plexiglass. … Cervical collars are incorporated into rigid braces that constrain the head and chest together. Examples include the Sterno-Occipital Mandibular Immobilization Device (SOMI), Lerman Minerva and Yale types.