home // Car Information // Chevrolet
C S I M V C C.J. Stankewich, Harborview Medical Center OVERVIEW
Source: www-nrd.nhtsa.dot.gov
File Size: 23.12 KB
Category: Car Information
Last Download : 11 days 4 hours 53 minutes ago
Share this info:
Short Description: He sustained a posterior C4-C5 lamina fracture with anterior subluxation and .... A 1991 Chevrolet Corvette was t-boned on the right side by a 1997 Plymouth ...
Content Inside: CERVICAL SPINE INJURIES IN MOTOR VEHICLE CRASHES C.J. Stankewich, Harborview Medical Center OVERVIEW Safety systems advances have had a profound effect in reducing injury in motor vehicle accidents. Automotive safety advances offering protection to the neck currently include seatbelts, airbags, and head rests. Seatbelts were designed to prevent occupants from being ejected, historically a frequent cause of neck injury. Seatbelts and airbags were also designed to protect the head, face and neck from contact with the vehicle interior. Head rests are intended to support the head and prevent hyperextension in rear impacts. The airbag has been proposed to offer protection against hyperflexion in frontal impacts, but its ability to limit cervical motion has not been proven. Despite gains in protection, crashes in late model vehicles may still result in injury to the cervical spine. Motor vehicle accidents are currently the most common cause of injury to the cervical spine (National Spinal Cord Injury Data), resulting in chronic pain, paralysis and death. The cervical spine functions to protect the spinal cord while allowing movement of the head. Structurally, complex motion of the head is provided by seven cervical vertebrae, each offering relative motion. Excessive motion, though, may result in bony or soft tissue damage to the cervical spine and may compromise its ability to protect the spinal cord. Injurious motion of the head may result from the dramatic accelerations or decelerations that occur in motor vehicle accidents. In addition, contact of the head with interior components of the vehicle may apply additional compressive, tensile or bending forces to the neck. Multiple mechanisms of injury to the cervical spine have been defined. These include excessive flexion, extension or lateral rotation that may be combined with compression or tension (Allan 1982). The specific anatomical structure and location of injury that the cervical spine sustains is dependent in the mechanism of injury applied. It is also sensitive to the initial position of the head relative to the neck, the rate of loading and the degree to which the neck is constrained also affect the tolerance. Individual parameters, including the presence of preexisting pathology or deformities, as well as the geometry and bone density, also effect biomechanics. Pediatric cervical spines behave differently from adult on due to anatomic features including proportionately heavier heads as well as material differences including greater ligament laxity and growth centers that are susceptible to shear forces (Orenstein 1984). In addition to the biomechanical complexities of the cervical spine, there are a myriad of occupant kinematics that can result from motor vehicle accidents. Injury can occur when the head moves relative to the torso with either sufficient rotation to exceed the normal range of motion or with sufficient force to load the cervical spine beyond its tolerances. In frontal crashes, the restraint system acts to rapidly decelerates the torso, while the head remains in motion until it reaches its end of range of motion in flexion.
