Types of collision include head-on, road departure, rear-end, side collisions, and rollovers. Many different terms are commonly used to describe vehicle collisions. The World Health Organization uses the term road traffic injury, while the U.S. Census Bureau uses the term motor vehicle accidents (MVA), and Transport Canada uses the term "motor vehicle traffic collision" (MVTC). Other common terms include auto accident, car accident, car crash, car smash, car wreck, motor vehicle collision (MVC), personal injury collision (PIC), road accident, road traffic accident (RTA), road traffic collision (RTC), and road traffic incident (RTI) as well as more unofficial terms including smash-up, pile-up, and fender bender. Some organizations have begun to avoid the term accident, instead preferring terms such as collision, crash or incident. This is because the term accident implies that there is no one to blame, whereas most traffic collisions are the result of driving under the influence, excessive speed, distractions such as mobile phones or other risky behavior.Historically, in the United States, the use of terms other than accident had been criticized for holding back safety improvements, based on the idea that a culture of blame may discourage the involved parties from fully disclosing the facts, and thus frustrate attempts to address the real root causes. Health effects
Physical
A number of physical injuries can commonly result from the blunt force trauma caused by a collision, ranging from bruising and contusions to catastrophic physical injury (e.g., paralysis), traumatic or non-traumatic cardiac arrest and death. Psychological
Following collisions, long-lasting psychological trauma may occur.
Degenerative disc disease can lead to a chronic debilitating condition and can have a serious negative impact on a persons quality of life. When pain from degenerative disc disease is severe, traditional nonoperative treatment may be ineffective. Cause
There is a disc between each of the vertebrae in the spine. A healthy, well-hydrated disc will contain a great deal of water in its center, known as the nucleus pulposus, which provides cushioning and flexibility for the spine. Much of the mechanical stress that is caused by everyday movements is transferred to the discs within the spine and the water content within them allows them to effectively absorb the shock. At birth, a typical human nucleus pulposus will contain about 80% water. However natural daily stresses and minor injuries can cause these discs to gradually lose water as the annulus fibrosus, or the tough outer fibrous material of a disc, weakens. Because degenerative disc disease is largely due to natural daily stresses, the American Academy of Orthopaedic Manual Physical Therapists have suggested it is not truly a "disease" process.This water loss makes the discs more flexible and results in the gradual collapse and narrowing of the gap in the spinal column. As the space between vertebrae gets smaller, extra pressure can be placed on the discs causing tiny cracks or tears to appear in the annulus. If enough pressure is exerted, it is possible for the nucleus pulposus material to seep out through the tears in the annulus and can cause what is known as a herniated disc.