Myth: Additional movement of the spine in a patient with a spinal injury would actually worsen the condition or result in a secondary injury. There are really no data to support this.
The natural responses of the body to a serious injury actually provide somewhat of a de facto splint. With C-spine injuries, the muscles of the neck contract and that, along with pain, limits additional severe motion (at least in a conscious patient)
There’s absolutely NO EVIDENCE the C-spine can be immobilized to any significant degree.