Chronic pain and whiplash associated disorders: rehabilitation and secondary prevention

Exercise therapy for whiplash-associated disorders: a systematic review and meta-analysis

OBJECTIVES

Acute as well as chronic pain syndromes are common after whiplash trauma and exercise therapy is proposed as one possible intervention strategy. The aim of the present systematic review was to evaluate the effect of exercise therapy in patients with Whiplash-Associated Disorders for the improvement of neck pain and neck disability, compared with other therapeutic interventions, placebo interventions, no treatment, or waiting list.

CONTENT

The review was registered in Prospero (CRD42017060356) and conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A literature search in PubMed, Scopus and Cochrane from inception until January 13, 2020 was combined with a hand search to identify eligible randomized controlled studies. Abstract screening, full text assessment and risk of bias assessment (Cochrane RoB 2.0) were conducted by two independent reviewers.

SUMMARY

The search identified 4,103 articles. After removal of duplicates, screening of 2,921 abstracts and full text assessment of 100 articles, 27 articles that reported data for 2,127 patients were included. The included articles evaluated the effect of exercise therapy on neck pain, neck disability or other outcome measures and indicated some positive effects from exercise, but many studies lacked control groups not receiving active treatment. Studies on exercise that could be included in the random-effect meta-analysis showed significant short-term effects on neck pain and medium-term effects on neck disability.

OUTLOOK

Despite a large number of articles published in the area of exercise therapy and Whiplash-Associated Disorders, the current evidence base is weak. The results from the present review with meta-analysis suggests that exercise therapy may provide additional effect for improvement of neck pain and disability in patients with Whiplash-Associated Disorders.

Catastrophizing and perceived injustice: risk factors for the transition to chronicity after whiplash injury

STUDY DESIGN

The article will summarize research that has supported the role of pain catastrophizing and perceived injustice as risk factors for problematic recovery after whiplash injury.

OBJECTIVE

This article focuses on two psychological variables that have been shown to impact on recovery trajectories after whiplash injury; namely pain catastrophizing and perceived injustice.

SUMMARY OF BACKGROUND DATA

Research has shown that psychological variables play a role in determining the trajectory of recovery after whiplash injury.

METHODS

This article will focus on two psychological variables that have been shown to impact on recovery trajectories after whiplash injury; namely pain catastrophizing and perceived injustice. The article will summarize research that has supported the role of pain catastrophizing and perceived injustice as risk factors for problematic recovery after whiplash injury.

RESULTS

Several investigations have shown that measures of catastrophizing and perceived injustice prospectively predict problematic trajectories of recovery after whiplash injury. Basic research points to the potential roles of expectancies, attention, coping and endogenous opioid dysregulation as possible avenues through which catastrophizing might heighten the probability of the persistence of pain after whiplash injury. Although research has yet to systematically address the mechanisms by which perceived injustice might contribute to prolonged disability in individuals with whiplash injuries, there are grounds for suggesting the potential contributions of catastrophizing, pain behavior and anger.

CONCLUSION

A challenge for future research will be the development and evaluation of risk factor-targeted interventions aimed at reducing catastrophizing and perceived injustice to improve recovery trajectories after whiplash injury.

Quality of life in subgroups of individuals with whiplash-associated disorders

BACKGROUND

The term whiplash associated disorders (WAD) includes a wide range of complaints, with neck pain as predominating symptom. Living with long term pain influences quality of life. In previous studies of other chronic pain patients, subgrouping has been made according to thermal pain thresholds measured in quantitative sensory testing (QST).

AIMS

The aims of the present study are threefold, (1) to evaluate thermal pain thresholds and health related quality of life in WAD patients compared to healthy pain-free individuals, (2) to explore whether subgrouping of the WAD patients is possible according to thermal pain thresholds over trapezius, and if so (3) to explore differences between the subgroups.

METHODS

Twenty-six patients with WAD and 18 healthy pain-free controls took part in the study. Thermal pain thresholds were measured in two sites (over the thenar and the trapezius muscle) using quantitative sensory testing (QST). Health related quality of life (HRQoL) was assessed using the SF-36. The visual analogue scale was used to rate pain intensity and unpleasantness related to the experimental situation.

RESULTS

WAD patients are more sensitive to thermal pain, and scored lower on the SF-36 in all scales when compared with healthy pain-free individuals. After analyzing clusters (K-means algorithm) two subgroups of WAD emerge, pain insensitive and pain sensitive. The pain insensitive group differed significantly from the pain sensitive group in the Role Emotional subscale of SF-36 (p=0.025).

CONCLUSIONS

Thermal pain hyperalgesia, especially for cold, seems to be a determinant for subgrouping WAD patients. These results support that such a classification of a heterogenous group could be of importance in tailoring treatment and early interventions.

Measurement of cervical flexor endurance following whiplash

AIM

To investigate measurement properties of a practical test of cervical flexor endurance (CFE) in whiplash patients including inter-rater reliability, sensitivity to clinical change, criterion related validity against the Neck Disability Index (NDI), and discriminant validity for injured versus uninjured populations.

METHODS

Two samples were recruited, 81 whiplash patients, and a convenience sample of 160 subjects who were not seeking treatment and met criteria for normal pain and range of motion. CFE was measured using a stopwatch while the subject, in crook lying, held their head against gravity to fatigue.

RESULTS

Inter-rater reliability in whiplash patients was in a range considered 'almost perfect' (Intraclass Correlation=0.96). CFE had greater inter-subject variability than the NDI or range of motion in any of three planes. However, the effect size for improvement in CFE over treatment was as large as the effect sizes for all of those measures. In multivariate regression, CFE changes accounted for changes on the NDI better than the three ranges of motion. CFE discriminated whiplash patients who were within six months of injury (n=71) from age and gender matched normals with high effect size (ES=1.5).

CONCLUSIONS

These findings provide evidence of reliability and validity for CFE measurement, and demonstrate that CFE detects clinical improvements. Variance on CFE emphasizes the need to consider inter-, and intra-subject standard deviations to interpret scores.