Whiplash Subjects Research Articles

Cervicocephalic kinesthetic sensibility in patients with whiplash injury

This study investigated cervicocephalic kinesthetic sensibility in patients with whiplash injury and the effects of a rehabilitation programme. Fourteen patients with a whiplash injury and 34 healthy subjects participated in this study. The ability to appreciate both movement and the position of the head with respect to the trunk was investigated. Active head repositioning was significantly less precise in the whiplash subjects compared to the control group. Repositioning was more precise in whiplash subjects after the 5-week rehabilitation programme. There was no correlation between error of repositioning in patients and pain intensity. It is probable that cervicocephalic kinesthesia is linked to sensory information from the extensive muscular and articular proprioceptive system. A flexion-extension injury to the neck may result in dysfunction of this system.

Confirmatory Factor Analysis and Multiple Linear Regression of the Neck Disability Index: Assessment If Subscales Are Equally Relevant in Whiplash and Nonspecific Neck Pain

ObjectiveBecause of previously published recommendations to modify the Neck Disability Index (NDI), we evaluated the responsiveness and dimensionality of the NDI within a population of adult whiplash-injured subjects. The purpose of the present study was to evaluate the responsiveness and dimensionality of the NDI within a population of adult whiplash-injured subjects. MethodsSubjects who had sustained whiplash injuries of grade 2 or higher completed an NDI questionnaire. There were 123 subjects (55% female, of which 36% had recovered and 64% had chronic symptoms. NDI subscales were analyzed using confirmatory factor analysis, considering only the subscales and, secondly, using sex as an 11th variable. The subscales were also tested with multiple linear regression modeling using the total score as a target variable. ResultsWhen considering only the 10 NDI subscales, only a single factor emerged, with an eigenvalue of 5.4, explaining 53.7% of the total variance. Strong correlation (>.55) (P < .0001) between all variables was found. Multiple linear regression modeling revealed high internal consistency with all coefficients reaching significance (P < .0001). The 4 NDI subscales exerting the greatest effect were, in decreasing order, Sleeping, Lifting, Headaches, and Pain Intensity. ConclusionA 2-factor model of the NDI is not justified based on our results, and in this population of whiplash subjects, the NDI was unidimensional, demonstrating high internal consistency and supporting the original validation study of Vernon and Mior.

CSM 2015 Orthopaedic Section Platform Presentations (Abstracts OPL1–OPL63)

CSM 2015 Orthopaedic Section Platform Presentations (Abstracts OPL1–OPL63)

Self-rated disability, fear-avoidance beliefs, nonorganic pain behaviors are important mediators of ranges of active motion in chronic whiplash patients

Purpose: The influence of self-rated disability and fear-avoidance beliefs on whiplash sufferers in their performance of active ranges of motion has not been studied well. We undertook a cross-sectional study to determine this. Methods: Chronic whiplash subjects completed a standard clinical examination. They completed the Neck Disability Index (NDI), the Tampa Scale for Kinesiophobia (TSK) and pain visual analog scale (VAS). Active ranges of motion (goniometer) and cervical nonorganic simulation signs (C-NOSS) were obtained by the examiner. Univariate and multivariable analyses were conducted on these scores. Results: Sixty-four subjects (37 female) with a mean age of 41.4 (SD 16.1) years completed all scores. NDI, pain VAS and C-NOSS correlated significantly with ROM. In a multivariable model, only the NDI score contributed significantly to the variance of the ROM scores (14%). Conclusion: As chronic whiplash sufferers perform ROM in a clinical examination, these ranges are importantly influenced by their self-perceived disability. Cervical nonorganic simulation signs can be helpful in distinguishing high from very high levels of disability and motion restriction. The lack of correlation with the TSK may present a challenge to the Fear Avoidance Model in whiplash.Implications for RehabilitationSelf-ratings of disability in chronic whiplash sufferers are influenced by their fear-avoidance beliefs.While self-ratings of disability are known to predict chronicity of whiplash, there is less known about how these ratings affect impairment assessment during recovery.This study shows that self-ratings of disability influence the presentation of impairment by chronic whiplash sufferers with respect to their ranges of neck motion.Signs of nonorganic behavior also influence ranges of motion and self-ratings of disability.These findings should be incorporated into the interpretation of impairment findings in chronic whiplash sufferers in order to improve management.

Head Eye Co-ordination Using Simultaneous Measurement of Eye in Head and Head in Space Movements: Potential For Use in Subjects With a Whiplash Injury

Describe reproducibility of a measurement method to investigate deficits in eye-head co-ordination. Combined recordings of head and eye rotation using wireless motion sensors and electro-oculography (EOG) were used as an initial step towards a method to quantify eye-head co-ordination deficits. Head rotation to the side during gaze fixation and sequential head and eye movements were studied on 20 asymptomatic control subjects and six subjects with chronic whiplash disorders. All included whiplash subjects reported eye disturbances according to a vision symptom questionnaire. The trial-to-trial reproducibility was moderate to high for 24 of 28 variables (Intraclass Correlation Coefficient 0.44 to 0.87). Velocity gain (ratio of eye and head velocities) was on average close to unity in both groups. Head stability was high in control subjects, while three of six whiplash subjects demonstrated head instability during eye movement. Whiplash subjects also demonstrated a decreased range of head movement during gaze fixation and lower head velocities as compared with the asymptomatics. The method of combined head and eye motion appears to give accurate, repeatable measurements. Case studies of whiplash subjects indicated deficits in head eye co-ordination. The method could be useful in further clinical research into eye and head movement in those with neck disorders.

MRI analysis of the size and shape of the oropharynx in chronic whiplash

To quantify differences in the size/shape of the oropharynx between female subjects with whiplash and controls. Retrospective cohort. A total of 113 subjects (79 whiplash, 34 controls) were included. T1-weighted MRI was used to measure 1) cross-sectional area (CSA [mm(2)]) and 2) shape ratios for the oropharynx. Reliability data were established. Whiplash subjects had significantly smaller oropharynx CSAs (P < 0.001) and shape ratios (P < 0.001) compared with healthy controls. Self-reported levels of pain and disability and duration of symptoms were not associated with size and shape of the oropharynx in whiplash subjects (P = 0.75 and P = 0.99, respectively). Age and BMI did influence the size (P = 0.01) and shape of the oropharynx (P < 0.001) in the whiplash subjects, but only 20 to 30 percent of the variance could be explained by these factors. Significant difference in the size and shape of the oropharynx was noted in subjects with chronic whiplash compared with controls. Future studies are required to investigate the relationships between oropharynx morphometry and symptoms in patients with chronic whiplash.

Neuromuscular control of the head in an isometric force reproduction task: comparison of whiplash subjects and healthy controls

Background context A number of recent scientific publications suggest that patients suffering from whiplash-associated disorders (WADs) exhibit sensorimotor deficits in the control of head and neck movements. Purpose The main objective of the present study was to evaluate if subjects with WADs can produce isometric neck extension and flexion forces with precision, variability, and a mode of control similar to the values of healthy subjects. Study design A control group study with repeated measures. Patient samples Neck force production parameters and neuromuscular control were measured in 17 whiplash and 14 control subjects. The experimental group included subjects who had a history of persistent neck pain or disability after a motor vehicle accident. Outcome measures Pain levels were assessed on a standard 100-mm visual analog pain scale at the beginning and end of the experiment. Each whiplash subject completed the neck disability index and the short-form 36 health survey (SF-36) questionnaire before the experiment. Methods All subjects were asked to exert flexion and extension forces against a fixed head harness. Kinetic variables included time to peak force, time to peak force variability, peak force variability, and absolute error in peak force. Surface electrodes were applied bilaterally over the sternocleidomastoideus and paraspinal muscles. Electromyography (EMG)-dependent variables included EMG burst duration and amplitude using numerical integrated techniques. Results The average time to peak force was significantly longer for whiplash subjects than for the healthy controls. A significant increase in peak force variability was also observed in the whiplash group, and no group differences were noted for absolute error. Heightened muscular activity was seen in both paraspinal muscles, even though it only reached statistical significance for the left paraspinal muscle. Conclusion Our results show that the whiplash subjects involved in the study were able to produce isometric forces with spatial precision similar to healthy controls using a motor strategy in which the time to peak force is increased. This trade-off between spatial precision and time to peak force probably reflects an adaptation aimed at limiting pain and further injuries.

Head and neck position sense in whiplash patients and healthy individuals and the effect of the cranio-cervical flexion action

Whiplash may damage structures within the neck that can affect position sense. Deep neck flexor muscle retraining may improve position sense. The current study compared range of motion and position sense in whiplash and control subjects and investigated the effects of a muscle training session on position sense. Twenty-three subjects with whiplash were compared with a matched control group. Range of motion and neck position sense measures were recorded using the 3-Space Fastrak. Measures of function were also assessed in the whiplash group. Subjects were then randomised into experimental and control groups and the former group received a training session to activate the deep neck flexor and scapular stabilising muscles (the cranio-cervical flexion action) during head and neck movements. After training, position sense measures were re-evaluated. Results showed significant reductions (P < 0.05) in active range of motion in the whiplash group when compared to the healthy group. No significant differences (P > 0.05) between whiplash and healthy groups in position matching accuracy were observed. Functional outcome scores indicated the whiplash group to be mildly disabled. No effect on error scores was observed when position-matching tasks were performed with and without the cranio-cervical flexion action. Correlations between functional measures or range of motion, and position sense were not significant. There was no evidence of position sense impairment in the mildly disabled whiplash subjects. The performance of the cranio-cervical flexion action had no effect on position sense, and hence clinical improvements observed from using this action may be more associated with mechanical stabilisation.

Widespread Sensory Hypersensitivity Is a Feature of Chronic Whiplash-Associated Disorder but not Chronic Idiopathic Neck Pain

To investigate sensory changes present in patients with chronic whiplash-associated disorders and chronic idiopathic neck pain using a variety of quantitative sensory tests to better understand the pain processing mechanisms underlying persistent symptoms. A case control study was used with 29 subjects with chronic whiplash-associated disorders, 20 subjects with chronic idiopathic neck pain, and 20 pain-free volunteers. Pressure pain thresholds were measured over the articular pillars of C2-C3, C5-C6, the median, radial, and ulnar nerve trunks in the arm and over a remote site, the muscle belly of tibialis anterior. Heat pain thresholds, cold pain thresholds, and von Frey hair sensibility were measured over the cervical spine, tibialis anterior, and deltoid insertion. Anxiety was measured with the Short-Form of the Spielberger State Anxiety Inventory. Pressure pain thresholds were decreased over cervical spine sites in both subject groups when compared with controls (P < 0.05). In the chronic whiplash-associated disorders group, pressure pain thresholds were also decreased over the tibialis anterior, median, and radial nerve trunks (P < 0.001). Heat pain thresholds were decreased and cold pain thresholds increased at all sites (P < 0.03). No differences in heat pain thresholds or cold pain thresholds were evident in the idiopathic neck pain group at any site compared with the control group (P > 0.27). No abnormalities in von Frey hair sensibility were evident in either neck pain group (P > 0.28). Both chronic whiplash-associated disorders and idiopathic neck pain groups were characterized by mechanical hyperalgesia over the cervical spine. Whiplash subjects showed additional widespread hypersensitivity to mechanical pressure and thermal stimuli, which was independent of state anxiety and may represent changes in central pain processing mechanisms. This may have implications for future treatment approaches.

Is the method of signal analysis and test selection important for measuring standing balance in subjects with persistent whiplash?

Dizziness and or unsteadiness, associated with episodes of loss of balance, are frequent complaints in those suffering from persistent problems following a whiplash injury. Research has been inconclusive with respect to possible aetiology, discriminative tests and analyses used. The aim of this pilot research was to identify the test conditions and the most appropriate method for the analysis of sway that may differentiate subjects with persistent whiplash associated disorders (WAD) from healthy controls. The six conditions of the Clinical Test for Sensory Interaction in Balance was performed in both comfortable and tandem stance in 20 subjects with persistent WAD compared to 20 control subjects. The analyses were carried out using a traditional method of measurement, total sway distance, to results obtained from the use of wavelet analysis. Subjects with WAD were significantly less able to complete the tandem stance tests on a firm surface than controls. In comfortable stance, using wavelet analysis, significant differences between subjects with WAD and the control group were evident in total energy of the trace for all test conditions apart from eyes open on the firm surface. In contrast, the results of the analysis using total sway distance revealed no significant differences between groups across all six conditions. Wavelet analysis may be more appropriate for detecting disturbances in balance in whiplash subjects because the technique allows separation of the noise from the underlying systematic effect of sway. These findings will be used to direct future studies on the aeitiology of balance disturbances in WAD.

Segmental vertebral motion in the assessment of neck range of motion in whiplash patients.

The purpose of this study was to obtain comparative data concerning the relative contribution of segmental cervical vertebral motion to the cervical range of motion (ROM) in whiplash and healthy subjects in an effort to evaluate the usefulness of X-ray analysis in future forensic and research efforts. Each subject's neck ROM was measured with an optoelectronic system and also by X-ray measurements of the angular rotation in flexion and extension. The X-rays were examined to calculate the angular movement in the sagittal plane of each of the functional units C2-C3 to C6-C7. The chronic whiplash subjects showed reduced total neck range in all directions as compared to healthy subjects (p<0.001). There was a reduced total angular rotation from flexion to extension between these two groups (p<0.01), but no significant difference, however, between chronic whiplash subjects and controls in the percentage contribution of each of the functional units C2-C3 to C6-C7 to this rotation. This data will now allow a design of trials where healthy subjects are asked to simulate restricted neck ROM while undergoing optokinetic and X-ray evaluation of segmental vertebral motion. We will be able to determine if simulators produce a similar pattern to chronic whiplash and healthy, non-simulating subjects, and thus determine if, at least for forensic and research purposes, this technique is useful in validating reported restricted neck range.

The development of psychological changes following whiplash injury

Psychological distress is a feature of chronic whiplash-associated disorders, but little is known of psychological changes from soon after injury to either recovery or symptom persistence. This study prospectively measured psychological distress (General Health Questionnaire 28, GHQ-28), fear of movement/re-injury (TAMPA Scale of Kinesphobia, TSK), acute post-traumatic stress (Impact of Events Scale, IES) and general health and well being (Short Form 36, SF-36) in 76 whiplash subjects within 1 month of injury and then 2, 3 and 6 months post-injury. Subjects were classified at 6 months post-injury using scores on the Neck Disability Index: recovered (<8), mild pain and disability (10–28) or moderate/severe pain and disability (>30). All whiplash groups demonstrated psychological distress (GHQ-28, SF-36) to some extent at 1 month post-injury. Scores of the recovered group and those with persistent mild symptoms returned to levels regarded as normal by 2 months post-injury, parallelling a decrease in reported pain and disability. Scores on both these tests remained above threshold levels in those with ongoing moderate/severe symptoms. The moderate/severe and mild groups showed elevated TSK scores at 1 month post-injury. TSK scores decreased by 2 months in the group with residual mild symptoms and by 6 months in those with persistent moderate/severe symptoms. Elevated IES scores, indicative of a moderate post-traumatic stress reaction, were unique to the group with moderate/severe symptoms. The results of this study demonstrated that all those experiencing whiplash injury display initial psychological distress that decreased in those whose symptoms subside. Whiplash participants who reported persistent moderate/severe symptoms at 6 months continue to be psychologically distressed and are also characterised by a moderate post-traumatic stress reaction.

Effect of whiplash injury on accommodation.

Accommodative disturbance has been cited as one of the causes of visual disturbance following whiplash injury but to date, with one exception, none of the studies have incorporated a group of control subjects; none of the results have been statistically analysed. The aim of the present study was to examine the amplitude of accommodation in a group of whiplash subjects, the majority of whom had specifically complained of visual/ocular symptoms. The whiplash group consisted of 19 subjects and the control group consisted of 43 subjects. The amplitude of accommodation of the right and left eyes of the whiplash and control group subjects was measured and the results of the two groups compared. There was reduced amplitude of accommodation of the right (P = 0.02) and left (P = 0.02) eyes in the whiplash group subjects compared to the control group subjects. These results indicate that whiplash was associated with defective accommodation in the present select group of whiplash subjects.

Sensory hypersensitivity occurs soon after whiplash injury and is associated with poor recovery

Hypersensitivity to a variety of sensory stimuli is a feature of persistent whiplash associated disorders (WAD). However, little is known about sensory disturbances from the time of injury until transition to either recovery or symptom persistence. Quantitative sensory testing (pressure and thermal pain thresholds, the brachial plexus provocation test), the sympathetic vasoconstrictor reflex and psychological distress (GHQ-28) were prospectively measured in 76 whiplash subjects within 1 month of injury and then 2, 3 and 6 months post-injury. Subjects were classified at 6 months post-injury using scores on the Neck Disability Index: recovered (<8), mild pain and disability (10–28) or moderate/severe pain and disability (>30). Sensory and sympathetic nervous system tests were also measured in 20 control subjects. All whiplash groups demonstrated local mechanical hyperalgesia in the cervical spine at 1 month post-injury. This hyperalgesia persisted in those with moderate/severe symptoms at 6 months but resolved by 2 months in those who had recovered or reported persistent mild symptoms. Only those with persistent moderate/severe symptoms at 6 months demonstrated generalised hypersensitivity to all sensory tests. These changes occurred within 1 month of injury and remained unchanged throughout the study period. Whilst no significant group differences were evident for the sympathetic vasoconstrictor response, the moderate/severe group showed a tendency for diminished sympathetic reactivity. GHQ-28 scores of the moderate/severe group were higher than those of the other two groups. The differences in GHQ-28 did not impact on any of the sensory measures. These findings suggest that those with persistent moderate/severe symptoms at 6 months display, soon after injury, generalised hypersensitivity suggestive of changes in central pain processing mechanisms. This phenomenon did not occur in those who recover or those with persistent mild symptoms.

Development of motor system dysfunction following whiplash injury

Dysfunction in the motor system is a feature of persistent whiplash associated disorders. Little is known about motor dysfunction in the early stages following injury and of its progress in those persons who recover and those who develop persistent symptoms. This study measured prospectively, motor system function (cervical range of movement (ROM), joint position error (JPE) and activity of the superficial neck flexors (EMG) during a test of cranio-cervical flexion) as well as a measure of fear of re-injury (TAMPA) in 66 whiplash subjects within 1 month of injury and then 2 and 3 months post injury. Subjects were classified at 3 months post injury using scores on the neck disability index: recovered (<8), mild pain and disability (10–28) or moderate/severe pain and disability (>30). Motor system function was also measured in 20 control subjects. All whiplash groups demonstrated decreased ROM and increased EMG (compared to controls) at 1 month post injury. This deficit persisted in the group with moderate/severe symptoms but returned to within normal limits in those who had recovered or reported persistent mild pain at 3 months. Increased EMG persisted for 3 months in all whiplash groups. Only the moderate/severe group showed greater JPE, within 1 month of injury, which remained unchanged at 3 months. TAMPA scores of the moderate/severe group were higher than those of the other two groups. The differences in TAMPA did not impact on ROM, EMG or JPE. This study identifies, for the first time, deficits in the motor system, as early as 1 month post whiplash injury, that persisted not only in those reporting moderate/severe symptoms at 3 months but also in subjects who recovered and those with persistent mild symptoms.

Responses to a clinical test of mechanical provocation of nerve tissue in whiplash associated disorder

Involvement of nerve tissue may contribute to the persistence of pain following a whiplash injury. This study aimed to investigate responses to the brachial plexus provocation test (BPPT) in 156 subjects with chronic whiplash associated disorder (WAD) with and without associated arm pain and 95 asymptomatic control subjects. The range of elbow extension (ROM) and visual analogue scale (VAS) pain scores were measured. Subjects with chronic WAD demonstrated significantly less ROM and higher VAS scores with the BPPT than the asymptomatic subjects (P<0.001). These effects occurred bilaterally. Within the whiplash population, subjects whose arm pain was reproduced by the BPPT demonstrated significantly less ROM on both the symptomatic and asymptomatic sides when compared to the whiplash subjects whose arm pain was not reproduced by the BPPT (P=0.003) and significantly less ROM and higher VAS scores than those whiplash subjects with no arm pain (P=0.003, 0.01). Only the whiplash subjects whose arm pain was reproduced by the BPPT demonstrated differences between the symptomatic and asymptomatic sides. These generalized hyperalgesic responses to the BPPT support the hypothesis of central nervous system hypersensitivity as contributing to persistent pain experienced by WAD patients.

Deep Cervical Flexor Muscle Dysfunction in Whiplash

Objective: To measure the deep neck flexor muscle function for its contribution to cervical segmental stabilization.Methods: A staged test of deep neck flexor action, cranio-cervical flexion, was devised. Activity in the superficial neck flexors [electromyography] and the change in shape of the cervical curve, aligned to deep flexor contraction [pressure sensor] was measured, in whiplash subjects and asymptomatic controls.Results: Whiplash subjects used more activity in superficial muscles in the test and were less able to control pressure changes than controls.Conclusion: The test appears to detect poorer motor control in the neck flexors in whiplash subjects, the increased co-activation of the superficial neck flexors being a likely compensation for reduced deep neck flexor function.

Predictive factors for the outcome of a multidisciplinary pain rehabilitation programme on sick-leave and life satisfaction in patients with whiplash trauma and other myofascial pain: a follow-up study.

To evaluate the effects of a multidisciplinary rehabilitation programme on sick-leave, coping resources and life satisfaction in whiplash patients and other pain patients. Forty patients suffering from symptoms after whiplash trauma and 33 patients with musculoskeletal pain in the neck or back were recruited for this study. Ninety-seven consecutive patients admitted to the Department of Neurosurgery with cervical pain, cervical disc herniation or symptomatic spondylosis served as a control group. Decreased coping resources and poorer life satisfaction were observed for whiplash subjects at the beginning of the rehabilitation programme compared to the control group from the Department of Neurosurgery. After the rehabilitation period 49% of the patients had improved their coping resources totalling to 63% after 2 years. At that follow-up 46% of patients had increased their life satisfaction. Furthermore, the group with whiplash injury showed a significant increase in sick absenteeism whereas the group without whiplash trauma had decreased their sick-leave. Eighty-eight per cent of the subjects could be correctly classified according to their vocational outcome by means of discriminant function. The elapse of time since working, low life satisfaction, lack of increase in coping resources during the rehabilitation programme, ethnic origin of the patient and living in the countryside predicted poor vocational outcome. Our results suggest variables from the social environment and coping resources as useful predictors for treatment outcome.

Cervicocephalic kinesthetic sensibility, active range of cervical motion, and oculomotor function in patients with whiplash injury

Objective: To investigate cervicocephalic kinesthetic sensibility, active range of cervical motion, and oculomotor function in patients with whiplash injury. Design: A 2-year review of consecutive patients admitted to the emergency unit after whiplash injury. Setting: An otorhinolaryngology department. Patients and Subjects: Twenty-seven consecutive patients with diagnosed whiplash injury (14 men and 13 women, mean age, 33.8yrs [range, 18 to 66yrs]). The controls were healthy subjects without a history of whiplash injury. Main Outcome Measures: Oculomotor function was tested at 2 months and at 2 years after whiplash injury. The ability to appreciate both movement and head position was studied. Active range of cervical motion was measured. Subjective intensity of neck pain and major medical symptoms were recorded. Results: Active head repositioning was significantly less precise in the whiplash subjects than in the control group. Failures in oculomotor functions were observed in 62% of subjects. Significant correlations occurred between smooth pursuit tests and active cervical range of motion. Correlations also were established between the oculomotor test and the kinesthetic sensibility test. Conclusion: The results suggest that restricted cervical movements and changes in the quality of proprioceptive information from the cervical spine region affect voluntary eye movements. A flexion/extension injury to the neck may result in dysfunction of the proprioceptive system. Oculomotor dysfunction after neck trauma might be related to cervical afferent input disturbances.

Reduced cognitive functions in a group of whiplash patients with demonstrated disturbances in the posture control system

Past studies examining whether or not cognitive changes actually have occurred as a result of a whiplash (WL) accident have produced varying results. The aim of this study was to identify possible cognitive dysfunctions in a group with persistent problems after whiplash due to injuries to the posture control system and related structures. The whiplash subjects (n = 23) were selected on the basis of their reduced gain in the Smooth Pursuit Neck Torsion test (SPNT). The WL group differed significantly from a closely matched control group on tests of learning and memory, and prolonged divided attention and concentration. After attempting to rule out other ways of interpreting these differences (such as pain, depression, medication, and premorbid health problems), these data were interpreted as lending support to the notion of a causal connection between the disturbed posture control system and some cognitive malfunctions.