They are often used for herniated disks, pinched nerves, fractures, muscular strains and sprains (such as whiplash), or after an invasive procedure or injury. There are many types of cervical collars. The least restrictive, a soft collar, is often used in transition from a more rigid brace to none at all. A rigid collar such as the Philadelphia, Miami, Atlas, or Patriot collar is much more restrictive and is usually worn 24 hours a day until the injury has healed. Source Ortho proudly Features Cervical Collars by Aspen and ProCare.