A spinal cord injury (SCI) is damage to the spinal cord resulting in a temporary or permanent change in function, leading to altered sensation, strength, or function below the injury level. These injuries are almost always caused by a sudden, traumatic event that forcefully impacts the spine. Approximately 18,000 new cases of SCI occur annually in the United States. This article identifies the activities and circumstances statistically most likely to cause these injuries.
The Primary Mechanisms of Spinal Cord Injury
Motor vehicle crashes (MVCs) are consistently the leading cause of spinal cord injuries, accounting for approximately 38% of all new cases reported since 2015. The mechanisms often involve severe forces, including hyperflexion, hyperextension, and compression of the spine. Sudden deceleration, such as during a head-on collision, can cause fractures or dislocations of the vertebrae, subsequently damaging the spinal cord.
Falls represent the second-most frequent cause of spinal cord injuries, responsible for about 32% of cases. The percentage of SCIs caused by falls has increased steadily, corresponding with an aging population. Incidents include falls from a height, such as a ladder or roof, as well as falls on the same level due to slipping or tripping.
The third major category involves acts of violence, accounting for about 15% of all SCIs. The primary mechanism is penetrating trauma, with gunshot wounds being the most frequent cause. Unlike the blunt force trauma seen in crashes or falls, penetrating injuries directly sever or lacerate the spinal cord, often resulting in a complete injury.
Understanding Injury Mechanisms in High-Risk Recreation
While motor vehicle crashes and falls are the top statistical causes, sports and recreational activities account for about 8% of SCIs. Diving into shallow water is the single most common sports-related activity. This injury happens when the diver’s head strikes the bottom of a pool or natural body of water, leading to a specific mechanism called axial loading.
Axial loading transmits a compressive force directly through the top of the head and down the cervical spine, crushing the vertebrae. This force, often combined with hyperflexion, causes burst fractures or dislocations in the mid-to-lower cervical spine, typically at C5–C7. These injuries frequently result in severe neurological deficits, including tetraplegia.
Contact sports like football, rugby, and ice hockey also carry a notable risk, primarily through high-impact collisions. Spearing, hitting an opponent head-first, is a specific dangerous maneuver that can cause an axial loading injury similar to a shallow-water dive. Other recreational activities, such as horseback riding, cycling, and winter sports, contribute to the remaining sports-related SCIs through falls and high-velocity impacts.
Demographic Patterns and Risk Factors
Spinal cord injuries show a distinct demographic pattern that reflects the primary causes of injury. There is a strong gender disparity, with males accounting for approximately 78% to 79% of all new SCI cases. The average age of injury currently stands at 43 years old.
The age distribution shows two distinct peaks in incidence. Younger adults, particularly those between the ages of 16 and 30, are disproportionately affected by motor vehicle crashes and acts of violence. Older adults, especially those over the age of 65, see a significantly higher incidence of SCI due to falls.
The mechanism of injury also correlates with the severity or completeness of the injury. Blunt force trauma from crashes and falls often results in incomplete injuries, where some motor or sensory function is preserved below the injury level. In contrast, penetrating trauma, such as a gunshot wound, is more likely to result in a complete SCI due to the direct, destructive nature of the injury.