Whiplash injury is a common injures in our daily lives, but the mechanism of it and the best treatment is largely unknown. The development of chronic pain and disability following whiplash injury is not uncommon and results in substantial social and economic costs. Clinical manifestation and recovery time are difference, which make it difficult for doctor diagnosis and treatment. The current study have shown that the social class, severity of collision, compensation and lawsuit, physical and psychological factors were relevant predictors for the outcome of whiplash. This article is try to overview the status quo of the whiplash injury.
Cervical Vertebrae ; injuries ; Humans ; Prognosis ; Whiplash Injuries ; diagnosis ; pathology ; physiopathology ; therapy

Despite a large number of rear-end collisions on the road and a high frequency of whiplash injuries reported, the mechanism of whiplash injuries is not completely understood. One of the reasons is that the injury is not necessarily accompanied by obvious tissue damage detectable by X-ray or MRI. An extensive series of biomechanics studies, including injury epidemiology, neck kinematics, facet capsule ligament mechanics, injury mechanisms and injury criteria, were undertaken to help elucidate these whiplash injury mechanisms and gain a better understanding of cervical facet pain. These studies provide the following evidences to help explain the mechanisms of the whiplash injury: (1) Whiplash injuries are generally considered to be a soft tissue injury of the neck with symptoms such as neck pain and stiffness, shoulder weakness, dizziness, headache and memory loss, etc. (2) Based on kinematical studies on the cadaver and volunteers, there are three distinct periods that have the potential to cause injury to the neck. In the first stage, flexural deformation of the neck is observed along with a loss of cervical lordosis; in the second stage, the cervical spine assumes an S-shaped curve as the lower vertebrae begin to extend and gradually cause the upper vertebrae to extend; during the final stage, the entire neck is extended due to the extension moments at both ends. (3) The in vivo environment afforded by rodent models of injury offers particular utility for linking mechanics, nociception and behavioral outcomes. Experimental findings have examined strains across the facet joint as a mechanism of whiplash injury, and suggested a capsular strain threshold or a vertebral distraction threshold for whiplash-related injury, potentially producing neck pain. (4) Injuries to the facet capsule region of the neck are a major source of post-crash pain. There are several hypotheses on how whiplash-associated injury may occur and three of these injuries are related to strains within the facet capsule connected with events early in the impact. (5) There are several possible injury criteria to correlate with the duration of symptoms during reconstructions of actual crashes. These results form the biomechanical basis for a hypothesis that the facet joint capsule is a source of neck pain and that the pain may arise from large strains in the joint capsule that will cause pain receptors to fire.
Biomechanical Phenomena ; Cervical Vertebrae ; physiopathology ; Female ; Humans ; Male ; Neck ; physiopathology ; Shear Strength ; Whiplash Injuries ; classification ; diagnosis ; physiopathology

PURPOSE: Whiplash associated disorders remain a major health problem in terms of impact on health care and on societal costs. Aetiology remains controversial including the old supposition that the cervical muscles do not play a significant role. This study examined the muscle activity from relevant muscles during rear-end impacts in an effort to gauge their influence on the aetiology of whiplash associated disorders. METHODS: Volunteers were subjected to a sub-injury level of rear impact. Surface electromyography (EMG) was used to record cervical muscle activity before, during and after impact. Muscle response time and EMG signal amplitude were analysed. Head, pelvis, and T1 acceleration data were recorded. RESULTS: The activities of the cervical muscles were found to be significant. The sternocleidomastoideus, trapezius and erector spinae were activated on average 59 ms, 73 ms and 84 ms after the impact stimulus, respectively, prior to peak head acceleration (113 ms). CONCLUSION The cervical muscles reacted prior to peak head acceleration, thus in time to influence whiplash biomechanics and possibly injury mechanisms. It is recommended therefore, that muscular influences be incorporated into the development of the new rear-impact crash test dummy in order to make the dummy as biofidelic as possible.
Acceleration ; Accidents, Traffic ; Biomechanical Phenomena ; Electromyography ; Head ; physiopathology ; Humans ; Models, Biological ; Neck Muscles ; physiopathology ; Reaction Time ; Whiplash Injuries ; etiology ; physiopathology

Finite element method (FEM) is an effective mathematical method for stress analysis, and has been gradually applied in the study of biomechanics of human body structures. This paper reviews the construction, development, materials assignment and verification of FEM model of cervical vertebra, and it also states the research results of injury mechanism of whiplash injury and biomechanical response analysis of the cervical vertebra using FEM by researchers at home and abroad.
Adult ; Biomechanical Phenomena ; Cervical Vertebrae/physiopathology* ; Finite Element Analysis ; Humans ; Intervertebral Disc/physiopathology* ; Male ; Models, Anatomic ; Soft Tissue Injuries/physiopathology* ; Stress, Mechanical ; Whiplash Injuries/physiopathology*

There is a close functional relationship between the jaw and neck regions and it has been suggested that trigeminal sensory impairment can follow whiplash injury. Inclusion of manageable routines for valid assessment of the facial sensory capacity is thus needed for comprehensive evaluations of patients exposed to such trauma. The present study investigated facial thermal thresholds in patients with chronic whiplash-associated disorders (WADs) with both a qualitative method and quantitative sensory testing (QST). Ten women with pain and dysfunction following a whiplash injury were compared to 10 healthy age-matched women. Thermal detection thresholds were assessed by qualitative chair-side testing and by QST according to the method-of-limits. Seven test sites in the facial skin (overlying each trigeminal branch bilaterally, and the midpoint of the chin) were examined. The detection warm and cold thresholds were defined as the mean values of 10 individual thresholds. For the WAD patients, the qualitative assessment demonstrated both reduced and increased sensitivity compared to the healthy, whereas QST systematically showed significantly higher detection thresholds (i.e., decreased sensitivity) for both cold and warm stimuli. For the individuals who were assessed as having increased sensitivity in the qualitative assessment, the QST displayed either normal or higher thresholds, i.e., decreased sensitivity. The results suggest that QST is more sensitive for detecting thermal sensory disturbances in the face than a qualitative method. The impaired thermal sensitivity among the patients corroborates the notion of altered thermal detection capacity induced by WAD-related pain.
Case-Control Studies ; Chronic Disease ; Evaluation Studies as Topic ; Facial Pain ; etiology ; physiopathology ; Female ; Humans ; Neck Pain ; etiology ; physiopathology ; Sensory Thresholds ; Skin ; physiopathology ; Statistics, Nonparametric ; Thermosensing ; Trigeminal Nerve Injuries ; complications ; physiopathology ; Whiplash Injuries ; complications ; physiopathology

This study was conducted to develop a three-dimension finite element (FE) model of Chinese human neck for dynamic response during impact condition. A 50th percentile adult human in good health was chosen as a model. The 3-D FE model of C1-T1 was constructed by using of SCT scanning technology to get the data of DICOM format, using software Materialisc mimics, Pro-E to achieve three-dimension reconstruction, and using software TrueGrid to mesh. The model was composed of cervical vertebra, discs, facet joints, ligaments and muscles, which consisted of 24916 nodes and 15023 elements, including 14626 eight-node solid elements, 19 two-node link elements and 378 two-node cable elements. In LS-DYNA, the dynamic response of human neck under frontal impact was investigated and compared with experimental results so as to validate the model. The method proposed can develop complex FE model with eight-node elements fleetly and accurately in order to make computing more stably. The developed three-dimension FE model was used for dynamic response during impact condition, which may be helpful to studies on the injury of Chinese human neck.
Accidents, Traffic ; Adult ; Biomechanical Phenomena ; Cervical Vertebrae ; diagnostic imaging ; injuries ; physiology ; Finite Element Analysis ; Humans ; Imaging, Three-Dimensional ; methods ; Male ; Models, Biological ; Neck ; physiology ; Stress, Mechanical ; Tomography, Spiral Computed ; Whiplash Injuries ; etiology ; physiopathology