What low back pain is and why we need to pay attention

Low back pain is a very common symptom. It occurs in high-income, middle-income, and low-income countries and all age groups from children to the elderly population. Globally, years lived with disability caused by low back pain increased by 54% between 1990 and 2015, mainly because of population increase and ageing, with the biggest increase seen in low-income and middle-income countries. Low back pain is now the leading cause of disability worldwide. For nearly all people with low back pain, it is not possible to identify a specific nociceptive cause. Only a small proportion of people have a well understood pathological cause-eg, a vertebral fracture, malignancy, or infection. People with physically demanding jobs, physical and mental comorbidities, smokers, and obese individuals are at greatest risk of reporting low back pain. Disabling low back pain is over-represented among people with low socioeconomic status. Most people with new episodes of low back pain recover quickly; however, recurrence is common and in a small proportion of people, low back pain becomes persistent and disabling. Initial high pain intensity, psychological distress, and accompanying pain at multiple body sites increases the risk of persistent disabling low back pain. Increasing evidence shows that central pain-modulating mechanisms and pain cognitions have important roles in the development of persistent disabling low back pain. Cost, health-care use, and disability from low back pain vary substantially between countries and are influenced by local culture and social systems, as well as by beliefs about cause and effect. Disability and costs attributed to low back pain are projected to increase in coming decades, in particular in low-income and middle-income countries, where health and other systems are often fragile and not equipped to cope with this growing burden. Intensified research efforts and global initiatives are clearly needed to address the burden of low back pain as a public health problem.

A systematic review of psychological factors as predictors of chronicity/disability in prospective cohorts of low back pain

STUDY DESIGN

A systematic review of prospective cohort studies in low back pain.

OBJECTIVES

To evaluate the evidence implicating psychological factors in the development of chronicity in low back pain.

SUMMARY OF BACKGROUND DATA

The biopsychosocial model is gaining acceptance in low back pain, and has provided a basis for screening measurements, guidelines and interventions; however, to date, the unique contribution of psychological factors in the transition from an acute presentation to chronicity has not been rigorously assessed.

METHODS

A systematic literature search was followed by the application of three sets of criteria to each study: methodologic quality, quality of measurement of psychological factors, and quality of statistical analysis. Two reviewers blindly coded each study, followed by independent assessment by a statistician. Studies were divided into three environments: primary care settings, pain clinics, and workplace.

RESULTS

Twenty-five publications (18 cohorts) included psychological factors at baseline. Six of these met acceptability criteria for methodology, psychological measurement, and statistical analysis. Increased risk of chronicity (persisting symptoms and/or disability) from psychological distress/depressive mood and, to a lesser extent, somatization emerged as the main findings. Acceptable evidence generally was not found for other psychological factors, although weak support emerged for the role of catastrophizing as a coping strategy.

CONCLUSION

Psychological factors (notably distress, depressive mood, and somatization) are implicated in the transition to chronic low back pain. The development and testing of clinical interventions specifically targeting these factors is indicated. In view of the importance attributed to other psychological factors (particularly coping strategies and fear avoidance) there is a need to clarify their role in back-related disability through rigorous prospective studies.

Low back pain: a call for action

Low back pain is the leading worldwide cause of years lost to disability and its burden is growing alongside the increasing and ageing population.¹ Because these population shifts are more rapid in low-income and middle-income countries, where adequate resources to address the problem might not exist, the effects will probably be more extreme in these regions. Most low back pain is unrelated to specific identifiable spinal abnormalities, and our Viewpoint, the third paper in this Lancet Series,^2,3 is a call for action on this global problem of low back pain.

Diagnosis and classification of chronic low back pain disorders: maladaptive movement and motor control impairments as underlying mechanism

Low back pain (LBP) is a very common but largely self-limiting condition. The problem arises however, when LBP disorders do not resolve beyond normal expected tissue healing time and become chronic. Eighty five percent of chronic low back pain (CLBP) disorders have no known diagnosis leading to a classification of 'non-specific CLBP' that leaves a diagnostic and management vacuum. Even when a specific radiological diagnosis is reached the underlying pain mechanism cannot always be assumed. It is now widely accepted that CLBP disorders are multi-factorial in nature. However the presence and dominance of the patho-anatomical, physical, neuro-physiological, psychological and social factors that can influence the disorder is different for each individual. Classification of CLBP pain disorders into sub-groups, based on the mechanism underlying the disorder, is considered critical to ensure appropriate management. It is proposed that three broad sub-groups of CLBP disorders exist. The first group of disorders present where underlying pathological processes drive the pain, and the patients' motor responses in the disorder are adaptive. A second group of disorders present where psychological and/or social factors represent the primary mechanism underlying the disorder that centrally drives pain, and where the patient's coping and motor control strategies are mal-adaptive in nature. Finally it is proposed that there is a large group of CLBP disorders where patients present with either movement impairments (characterized by pain avoidance behaviour) or control impairments (characterized by pain provocation behaviour). These pain disorders are predominantly mechanically induced and patients typically present with mal-adaptive primary physical and secondary cognitive compensations for their disorders that become a mechanism for ongoing pain. These subjects present either with an excess or deficit in spinal stability, which underlies their pain disorder. For this group, physiotherapy interventions that are specifically directed and classification based, have the potential to impact on both the physical and cognitive drivers of pain leading to resolution of the disorder. Two case studies highlight the different mechanisms involved in patients with movement and control impairment disorder outlining distinct treatment approaches involved for management. Although growing evidence exists to support this approach, further research is required to fully validate it.

Chronic low back pain and fusion: a comparison of three surgical techniques: a prospective multicenter randomized study from the Swedish lumbar spine study group

STUDY DESIGN

A multicenter randomized study with a 2-year follow-up period and an independent observer was conducted.

OBJECTIVE

To compare three commonly used surgical techniques to achieve lumbar fusion primarily in terms of their ability to reduce pain and decrease disability in patients with severe chronic low back pain.

SUMMARY OF BACKGROUND DATA

Lumbar fusion can be used to reduce pain and decrease disability in patients with chronic low back pain, and different surgical techniques are available. The reported results after fusion surgery vary considerably, but most studies are retrospective and/or performed on heterogeneous patient groups. Spine surgeons commonly use the techniques presented in this report. However, in the absence of randomized trials it is difficult to know whether any one of them is better than the others for these patients.

METHODS

From 1992 through 1998, 294 patients referred to 19 spinal centers were blindly randomized into four treatment groups: three surgical groups (n = 222) and one nonsurgical group (n = 72). The sociodemographic and clinical characteristics did not differ among the groups. Eligibility included patients 25 to 65 years of age with therapy-resistant chronic low back pain that had persisted for at least 2 years and radiologic evidence of disc degeneration (spondylosis) at L4-L5, L5-S1, or both. Only patients randomized to one of three surgical groups were analyzed in the current study: Group 1 (posterolateral fusion; n = 73), Group 2 (posterolateral fusion combined with variable screw placement, an internal fixation device; n = 74), and Group 3 (posterolateral fusion combined with variable screw placement and interbody fusion; n = 75). The "circumferential fusion" in Group 3 was performed either as an anterior lumbar interbody fusion (n = 56) or as a biomechanically similar posterior lumbar interbody fusion (n = 19). The groups were composed of 51%, 58%, and 40% men respectively, and the respective mean ages were 44, 43, and 42 years. The patients had experienced low back pain for at least 2 years (mean, approximately 8 years). They had been on sick leave for approximately 3 years. Pain was measured by a visual analog scale, and disability was assessed by the Oswestry Low Back Pain Questionnaire, the Million Visual Analogue Score, and the General Function Score. Depressive symptoms were measured by the Zung Depression Scale. The global overall rating of the result was assessed by the patient and an independent observer after 2 years. Hospitalization data including operation time, blood loss, blood transfusion, and days of hospitalization in connection with surgery were reported, along with complications and the fusion rate. Records from the Swedish Social Insurance Board providing information on sick leave and economic compensation for Swedish residents were used to evaluate the patients' work status.

RESULTS

An independent observer examined 201 (91%) of 222 patients after 2 years, after 18 "group changers" and 3 dropouts had been excluded from the analyses. All surgical techniques were found to reduce pain and decrease disability substantially, but no significant differences were found among the groups. In all three groups, the patients rated the overall outcome similarly, as did the independent observer. The more demanding techniques in Groups 2 and 3 consumed significantly more resources in terms of operation time, blood transfusions, and days in hospital after surgery. The early complication rate was 6% in Group 1, 16% in Group 2, and 31% in Group 3. The fusion rate, as evaluated by plain radiograph, was 72% in Group 1, 87% in Group 2, and 91% in Group 3.

CONCLUSIONS

All the fusion techniques used in the study could reduce pain and improve function in this selected group of patients with severe chronic low back pain. There was no obvious disadvantage in using the least demanding surgical technique of posterolateral fusion without internal fixation.

The Tampa Scale for Kinesiophobia: further examination of psychometric properties in patients with chronic low back pain and fibromyalgia

The present study attempted to replicate the robustness of a two-factor model of the Tampa Scale for Kinesiophobia (TSK) in chronic low back pain (CLBP) patients and fibromyalgia patients, by means of confirmatory factor analysis. Construct and predictive validity of the TSK subscales were also examined. Results clearly indicated that a two-factor model fitted best in both pain samples. These two factors were labelled somatic focus, which reflects the belief in underlying and serious medical problems, and activity avoidance, which reflects the belief that activity may result in (re)injury or increased pain. Construct validity of the TSK and its subscales was supported by moderate correlation coefficients with self-report measures of pain-related fear, pain catastrophising, and disability, predominantly in patients with CLBP. Predictive validity was supported by moderate correlation coefficients with performance on physical performance tests (i.e., lifting tasks, bicycle task) mainly in CLBP patients. Implications of the results are discussed and directions for future research are provided.

The role of paraspinal muscle spindles in lumbosacral position sense in individuals with and without low back pain

STUDY DESIGN

A two-group experimental design with repeated measures on one factor was used.

OBJECTIVES

To investigate the role of paraspinal muscle spindles in lumbosacral position sense in individuals with and without low back pain.

SUMMARY OF BACKGROUND DATA

Proprioceptive deficits have been identified in patients with low back pain. The underlying mechanisms, however, are not well documented.

METHODS

Lumbosacral position sense was determined before, during, and after lumbar paraspinal muscle vibration in 23 young patients with low back pain and in 21 control subjects. Position sense was estimated by calculating the mean absolute error, constant error, and variable error between six criterion and reproduction sacral tilt angles.

RESULTS

Repositioning accuracy was significantly lower in the patient group than in healthy individuals (absolute error difference between groups = 2.7 degrees, P < 0.0001). Multifidus muscle vibration induced a significant muscle-lengthening illusion that resulted in an undershooting of the target position in healthy individuals (constant error = -3.1 degrees, P < 0.0001). Conversely, the position sense scores of the patient group did not display an increase in negative directional error but a significant improvement in position sense during muscle vibration (P < 0.05). No significant differences in absolute error were found between the first and last trial in the healthy individuals (P >/= 0.05) and in the patient group (P > 0.05).

CONCLUSIONS

Patients with low back pain have a less refined position sense than healthy individuals, possibly because of an altered paraspinal muscle spindle afference and central processing of this sensory input. Furthermore, muscle vibration can be an interesting expedient for improving proprioception and enhancing local muscle control.

Correlation between the MRI changes in the lumbar multifidus muscles and leg pain

AIM

In the assessment of the lumbar spine by magnetic resonance imaging (MRI), changes in the paraspinal muscles are frequently overlooked. In this study, our objective was to investigate the relationships between lumbar multifidus (MF) muscle atrophy and low back pain (LBP), leg pain and intevertebral disc degeneration.

METHODS

A retrospective study of 78 patients (aged 17-72) with LBP presenting with back pain with or without associated leg pain was undertaken. Their MR images were visually analysed for signs of lumbar MF muscle atrophy, disc degeneration and nerve root compression. The clinical history in each case was obtained from their case notes and pain drawing charts.

RESULTS

MF muscle atrophy was present in 80% of the patients with LBP. The correlation between MF muscle atrophy and leg pain was found to be significant (P < 0.01). However, the relationships between muscle atrophy and radiculopathy symptoms, nerve root compression, herniated nucleus pulposus and number of degenerated discs were statistically not significant.

CONCLUSION

Examination of the paraspinal muscles looking for atrophy of MF muscle should be considered when assessing MR images of lumbar spine. This may explain the referred leg pain in the absence of other MR abnormalities.

A randomized trial comparing acupuncture, simulated acupuncture, and usual care for chronic low back pain

BACKGROUND

Acupuncture is a popular complementary and alternative treatment for chronic back pain. Recent European trials suggest similar short-term benefits from real and sham acupuncture needling. This trial addresses the importance of needle placement and skin penetration in eliciting acupuncture effects for patients with chronic low back pain.

METHODS

A total of 638 adults with chronic mechanical low back pain were randomized to individualized acupuncture, standardized acupuncture, simulated acupuncture, or usual care. Ten treatments were provided over 7 weeks by experienced acupuncturists. The primary outcomes were back-related dysfunction (Roland-Morris Disability Questionnaire score; range, 0-23) and symptom bothersomeness (0-10 scale). Outcomes were assessed at baseline and after 8, 26, and 52 weeks.

RESULTS

At 8 weeks, mean dysfunction scores for the individualized, standardized, and simulated acupuncture groups improved by 4.4, 4.5, and 4.4 points, respectively, compared with 2.1 points for those receiving usual care (P < .001). Participants receiving real or simulated acupuncture were more likely than those receiving usual care to experience clinically meaningful improvements on the dysfunction scale (60% vs 39%; P < .001). Symptoms improved by 1.6 to 1.9 points in the treatment groups compared with 0.7 points in the usual care group (P < .001). After 1 year, participants in the treatment groups were more likely than those receiving usual care to experience clinically meaningful improvements in dysfunction (59% to 65% vs 50%, respectively; P = .02) but not in symptoms (P > .05).

CONCLUSIONS

Although acupuncture was found effective for chronic low back pain, tailoring needling sites to each patient and penetration of the skin appear to be unimportant in eliciting therapeutic benefits. These findings raise questions about acupuncture's purported mechanisms of action. It remains unclear whether acupuncture or our simulated method of acupuncture provide physiologically important stimulation or represent placebo or nonspecific effects.

The role of neuroticism, pain catastrophizing and pain-related fear in vigilance to pain: a structural equations approach

The present study aimed at clarifying the precise role of pain catastrophizing, pain-related fear and personality dimensions in vigilance to pain and pain severity by means of structural equation modelling. A questionnaire survey was conducted in 122 patients with chronic or recurrent low back pain. Results revealed that pain catastrophizing and pain-related fear mediated the relationship between neuroticism and vigilance to pain. Furthermore, vigilance to pain was found to be associated with heightened pain severity. Finally, we found that neuroticism moderated the relationship between pain severity and catastrophic thinking about pain. The results strongly support the idea that vigilance to pain is dependent upon catastrophic thinking and pain-related fear. Neuroticism is best conceived of as a vulnerability factor; it lowers the threshold at which pain is perceived as threatening, and at which catastrophic thoughts about pain emerge.

Effects of chronic low back pain on trunk coordination and back muscle activity during walking: changes in motor control

Low back pain (LBP) is often accompanied by changes in gait, such as a decreased (preferred) walking velocity. Previous studies have shown that LBP diminishes the normal velocity-induced transverse counter-rotation between thorax and pelvis, and that it globally affects mean erector spinae (ES) activity. The exact nature and causation of these effects, however, are not well understood. The aim of the present study was to examine in detail the effect of walking velocity on global trunk coordination and ES activity as well as their variability to gain further insights into the effects of non-specific LBP on gait. The study included 19 individuals with non-specific LBP and 14 healthy controls. Gait kinematics and ES activity were recorded during treadmill walking at (1) a self-selected (comfortable) velocity, and (2) sequentially increased velocities from 1.4 up to maximally 7.0 km/h. Pain intensity, fear of movement and disability were measured before the experiment. The angular movements of thorax, lumbar and pelvis were recorded in three dimensions. ES activity was recorded with pairs of surface electrodes. Trunk-pelvis coordination and mean amplitude of ES activity were analyzed. In addition, invariant and variant properties of trunk kinematics and ES activity were studied using principal component analysis (PCA). Comfortable walking velocity was significantly lower in the LBP participants. In the transverse plane, the normal velocity-induced change in pelvis-thorax coordination from more in-phase to more antiphase was diminished in the LBP participants, while lumbar and pelvis rotations were more in-phase compared to the control group. In the frontal plane, intersegmental timing was more variable in the LBP than in the control participants, with additional irregular movements of the thorax. Rotational amplitudes were not significantly different between the LBP and control participants. In the LBP participants, the pattern of ES activity was affected in terms of increased (residual) variability, timing deficits, amplitude modifications and frequency changes. The gait of the LBP participants was characterized by a more rigid and less variable kinematic coordination in the transverse plane, and a less tight and more variable coordination in the frontal plane, accompanied by poorly coordinated activity of the lumbar ES. Pain intensity, fear of movement and disability were all unrelated to the observed changes in coordination, suggesting that the observed changes in trunk coordination and ES activity were a direct consequence of LBP per se. Clinically, the results imply that conservative therapy should consider gait training as well as exercises aimed at improving both intersegmental and muscle coordination.

Disability resulting from occupational low back pain. Part II: What do we know about secondary prevention? A review of the scientific evidence on prevention after disability begins

This is the second of two papers that systematically review available scientific evidence on the causes of disability from occupational low back pain, and the effectiveness of interventions to prevent it after its onset (secondary prevention). This paper reviews the national history of how back pain and the risk factors for its extension into chronic disability, followed by a critical summary of intervention studies attempting to reduce the duration of this disability, and to evaluate the results.

Low Back Pain in Australian Adults. Prevalence and Associated Disability

OBJECTIVES

To determine the prevalence ranges of low back pain (LBP) together with any related disability in Australian adults.

DESIGN

A population-based survey.

METHODS

The survey was mailed in June 2001 to a stratified random sample of 3000 Australian adults selected from the Electoral Roll. Demographic variables of respondents were compared with the Australian population. Selective response bias was investigated using wave analysis. A range of prevalence data was derived, as were disability scores using the Chronic Pain Grade.

RESULTS

There was a 69% response rate. There was little variation between the sample and the Australian adult population. There was no significant selective response bias found. The sample point prevalence was estimated at 25.6% (95% confidence interval [CI], 23.6-27.5), 12-month prevalence was 67.6% (95% CI, 65.5-69.7), and lifetime prevalence was 79.2%, (95% CI, 77.3-81.0). In the previous 6-month period, 42.6% (95% CI, 40.4-44.8) of the adult population had experienced low-intensity pain and low disability from it. Another 10.9% (95% CI, 9.6-12.3) had experienced high intensity-pain but still low disability from this pain. However, 10.5% (95% CI, 9.2-11.9) had experienced high-disability LBP.

CONCLUSION

LBP is a common problem in the Australian adult population, yet most of this is low-intensity and low-disability pain. Nevertheless, over 10% had been significantly disabled by LBP in the past 6 months. Data from this study will provide a better understanding of the magnitude of the LBP problem in Australia, the need for access to health care resources, and also strategic research directions.

Confirmatory factor analysis of the Tampa Scale for Kinesiophobia: invariant two-factor model across low back pain patients and fibromyalgia patients

OBJECTIVES

(1) To investigate the factor structure of the Tampa Scale for Kinesiophobia (TSK) in a Dutch-speaking sample of chronic low back pain (CLBP) patients using confirmatory factor analysis, (2) to examine whether the internal structure of the TSK extends to another group of fibromyalgia (FM) patients, and (3) to investigate the stability of the factor structure in both patient groups using multi-sample analysis.

PATIENTS AND METHODS

TSK-data from 8 studies collected in Dutch and Flemish chronic pain patients were pooled. For 188 CLBP patients and 89 FM patients, complete data were available. Confirmatory factor analyses were performed to assess 4 models of kinesiophobia, and to examine which factor model provided the best fit. Furthermore, a multi-sample analysis was performed to investigate the stability of the factor structure in both patient groups.

RESULTS

For both CLBP and FM patients, the 2-factor model containing the factors "activity avoidance" and "pathologic somatic focus" was superior as compared with the 4-factor model containing the factors "harm," "fear of (re)injury." "importance of exercise," and "avoidance of activity". Moreover, the 2-factor model was found to be invariant across CLBP and FM patients, indicating that this model is robust in both pain samples.

DISCUSSION

As the 2-factor structure provided the best fit of the data in both patient samples, we recommend to use this version of the TSK and its 2 subscales in both clinical practice and research. Based on the content of the items, the subscales were labeled "Harm" and "Fear-avoidance."

Do attitudes and beliefs influence work loss due to low back trouble?

Recent evidence indicates that the influence of psychosocial factors on low back disability is as great as, if not greater than, ergonomic aspects; negative attitudes and beliefs are likely to be related to absenteeism. To measure workers attitudes and beliefs about low-back trouble, pain, work and activity five questionnaires were used. Two new instruments (Back Beliefs Questionnaire and Psychosocial Aspects of Work questionnaire) were developed and tested. The attitudes and beliefs were measured among workers in a biscuit manufacturing factory, and the responses related to absenteeism. Workers who had taken in excess of one week's absence due to low-back trouble had significantly more negative attitudes and beliefs when compared with workers who had taken shorter absence (or indeed those reporting no history of back trouble). A subset of the psychosocial parameters accounted for 32% of the variance in absence. Interventions designed to reduce negative attitudes and promote positive beliefs may help to reduce detrimental, inappropriate longer-term absenteeism due to low-back trouble.

Generalized deep-tissue hyperalgesia in patients with chronic low-back pain

Some chronic painful conditions including e.g. fibromyalgia, whiplash associated disorders, endometriosis, and irritable bowel syndrome are associated with generalized musculoskeletal hyperalgesia. The aim of the present study was to determine whether generalized deep-tissue hyperalgesia could be demonstrated in a group of patients with chronic low-back pain with intervertebral disc herniation. Twelve patients with MRI confirmed lumbar intervertebral disc herniation and 12 age and sex matched controls were included. Subjects were exposed to quantitative nociceptive stimuli to the infraspinatus and anterior tibialis muscles. Mechanical pressure (thresholds and supra-threshold) and injection of hypertonic saline (pain intensity, duration, distribution) were used. Pain intensity to experimental stimuli was assessed on a visual analogue scale (VAS). Patients demonstrated significantly higher pain intensity (VAS), duration, and larger areas of pain referral following saline injection in both infraspinatus and tibialis anterior. The patients rated significantly higher pain intensity to supra-threshold mechanical pressure stimulation in both muscles. In patients, the pressure pain-threshold was lower in the anterior tibialis muscle compared to controls. In conclusion, generalized deep-tissue hyperalgesia was demonstrated in chronic low-back pain patients with radiating pain and MRI confirmed intervertebral disc herniation, suggesting that this central sensitization should also be addressed in the pain management regimes.

Psychologic distress and low back pain. Evidence from a prospective study in the general population

STUDY DESIGN

The present is a prospective population-based cohort study.

OBJECTIVES

To determine whether psychologic distress in patients free of low back pain predicts future new episodes of such pain.

SUMMARY OF BACKGROUND DATA

An associating between symptoms of depression and anxiety and low back pain has been described in cross-sectional studies. It is unclear whether this represents cause or effect or whether it is found only in chronic pain sufferers attending specialist clinics. There is a need to investigate this prospectively in the general population.

METHODS

The study population was 4501 adults aged 18-75 years who responded to a questionnaire survey mailed to all those registered with two family practices in the United Kingdom. The survey inquired about low back pain during the previous month and included the 12-item General Health Questionnaire, a validated schedule for measuring psychologic distress in the general population. New episodes of low back pain during the 12 months after the survey were identified by two methods--continuous monitoring of all primary care consulters and a second postal survey at the end of the 12-month period to determine occurrences for which consultation had not been sought.

RESULTS

Among 1638 subjects free of current low back pain in the baseline survey, the likelihood of developing a new episode of nonconsulting low back pain was higher among those with General Health Questionnaire scores in the upper third of the range compared with the lower third (adjusted odds ratio, 1.8 [1.4, 2.4]). This could not be explained either by age and gender differences or by general physical health. The increased risk persisted when analysis was restricted to those who at baseline could not recall ever having had low back pain in the past and to those with full-time employment.

CONCLUSION

Symptoms of psychologic distress in individuals without back pain predict the subsequent onset of new episodes of low back pain. We calculate from these data that the proportion of new episodes of low back pain that might be attributable to such psychologic factors in the general population is 16%.

The Relationship Between Pain, Neuropsychological Performance, and Physical Function in Community-Dwelling Older Adults with Chronic Low Back Pain

OBJECTIVE

Chronic pain and cognitive impairment are prevalent and disabling in older adults (OA), but their interrelationship has not been rigorously tested. We did so in OA with chronic low back pain (CLBP).

DESIGN

A total of 323 OA (160 pain-free, 163 CLBP; mean age 73.5 years, 45% female) had neuropsychological (NP) testing with the Repeatable Battery for the Assessment of Neuropsychological Status, Trail Making Test, and the Grooved Pegboard Test. Pain intensity was measured with the McGill Pain Questionnaire Short Form. Physical performance (gait speed, functional reach, chair rise, trunk rotation, and static/dynamic lifting), psychosocial disruption (Geriatric Depression Scale, the Short Form-36 Mental Health and Role Limitations-Emotional Composite scale), and self-reported disability (Functional Status Index, the Short From-36 Physical Functioning/Role-Physical Composite scale) were also measured.

SETTING

Outpatient research laboratory.

RESULTS

There were no group differences in age, gender, or educational level, but significant differences in NP scores (P = 0.01) were found. Five scales accounted for the differences: immediate memory (P = 0.002), language (P = 0.004), delayed memory (P = 0.04), mental flexibility (Trails B [P = 0.02]), and Grooved Pegboard (P = 0.05). NP scores were significantly correlated with physical performance (R2= 0.30, P < 0.001), but not self-reported disability (R2= 0.04, P = 0.52) or psychosocial disruption (R2= 0.05, P = 0.46). NP function was correlated with pain intensity (R2= 0.17, P < 0.001), and NP function mediated the relationship between pain and physical performance.

CONCLUSIONS

OA with CLBP demonstrated impaired NP performance as compared with pain-free OA. Further, pain severity was inversely correlated with NP performance, and NP performance mediated the relationship between pain and physical performance. Future research should examine whether cognitive function and impaired physical performance can be improved with pain reduction.

The measurement of lumbar proprioception in individuals with and without low back pain

STUDY DESIGN

A clinical trial comparing a back pain group with a pain-free group.

OBJECTIVES

To investigate whether proprioceptive deficits existed in a group of individuals reporting low back pain.

SUMMARY OF BACKGROUND DATA

Little work has so far been conducted on the measurement of proprioception in the spine. Those studies that have been carried out, however, have failed to identify proprioceptive deficits in individuals with back pain. Previous work on peripheral joints has revealed that proprioception is affected with muscular or joint injury or degeneration.

METHODS

Forty individuals took part in the study, 20 with back pain and 20 with no pain. Participants were required to reproduce a predetermined target position, in standing and four-point kneeling, 10 times in 30 seconds. A computer screen was used to provide visual feedback on position. A mean deviation from the target position was obtained for each individual. A measurement of left elbow position sense was conducted in five individuals from each group to establish differences in short-term motor memory between the groups.

RESULTS

There were no differences between the subject groups in terms of short-term motor memory (P > 0.05). A two-way analysis of variance between subject groups and position to identify differences in accuracy (deviation from the target) found that there were differences between subject groups in either position (P < 0.05). There was no significant difference in accuracy between the positions used (P > 0.05).

CONCLUSIONS

Differences in proprioception do exist between individuals with back pain and those free from back pain. Further research needs to be undertaken on proprioceptive exercise programs and their effect on back pain.

CROSS-CULTURAL ADAPTATION OF THE NORWEGIAN VERSIONS OF THE ROLAND-MORRIS DISABILITY QUESTIONNAIRE AND THE OSWESTRY DISABILITY INDEX

OBJECTIVE

To evaluate reliability and construct validity of the Norwegian versions of the Roland Morris Disability Questionnaire and the modified Oswestry Disability Index.

DESIGN

Translation of two functional status questionnaires and a cross-sectional study of measurement properties.

METHODS

The questionnaires were translated and back-translated following the Guillemin criteria. The Norwegian versions were tested for 55 patients with acute low back pain and 50 patients with chronic low back pain. Test-retest with a 2-day interval was performed in a subsample of 28 patients from the chronic sample. Reliability was assessed by repeatability according to Bland and Altman, intraclass coefficient and coefficient of variation. Internal consistency was assessed by Cronbach's alpha. Concurrent construct validity was assessed with correlations between the questionnaires and the SF-36, Disability Rating Index and pain intensity.

RESULTS

Repeatability of the Roland Morris Disability Questionnaire was 4 points, coefficient of variation 15% and intraclass correlation coefficient 0.89, and of the modified Oswestry Disability Index 11, 12% and 0.88, respectively. Internal consistency was 0.94 for both questionnaires. The questionnaires correlated highly with the physical functioning scale of SF-36, moderately with pain, and low with mental scales of the SF-36.

CONCLUSION

The reliability and construct validity of the Norwegian versions of the Roland Morris Disability Questionnaire and the modified Oswestry Disability Index are acceptable for assessing functional status of Norwegian-speaking patients with low back pain.

Assessing change over time in patients with low back pain

BACKGROUND AND PURPOSE

This study compared the ability of the Roland-Morris (RM), Oswestry (OSW), and Jan van Breemen Institute (JVB) pain and function questionnaires to detect change over time.

SUBJECTS

The sample consisted of 88 patients with mechanical low back pain who were referred by physicians to the outpatient physical therapy department of a teaching hospital.

METHODS

Questionnaires were completed by the subjects at their initial visit and 4 to 6 weeks later. Clinically important change was estimated by having the subject and the clinician independently complete two rating scales. Sensitivity to change was assessed using receiver operating characteristic (ROC) curve analysis.

RESULTS

The ROC curve areas for the RM (0.79), OSW (0.78), and JVB pain (0.79) questionnaires were significantly greater than for the JVB function questionnaire (0.66). Blank and multiple responses per item were present on approximately 20% of the OSW questionnaires and 14% of the JVB questionnaires. Words rather than checks were evident on 3% of the RM questionnaires.

CONCLUSION AND DISCUSSION

Based on the latter finding, we believe the RM questionnaire may be the preferred instrument for assessing change over time in patients with low back pain.

Disability resulting from occupational low back pain. Part I: What do we know about primary prevention? A review of the scientific evidence on prevention before disability begins

This is the first of two papers that systematically review available scientific evidence on the causes of disability from occupational low back pain, and the effectiveness of interventions to prevent it-before disability begins (primary prevention-Part I) and after its onset (secondary prevention-Part II). This first paper reviews the risk factors for the onset of pain and associated disability followed by a critical summary of intervention studies attempting to achieve prevention and to evaluate the results.

Disuse and deconditioning in chronic low back pain: concepts and hypotheses on contributing mechanisms

For years enhancement of a patient's level of physical fitness has been an important goal in rehabilitation treatment in chronic low back pain (CLBP), based on the hypothesis that physical deconditioning contributes to the chronicity of low back pain. However, whether this hypothesis in CLBP holds is not clear. In this paper, possible mechanisms that contribute to the development of physical deconditioning in CLBP, such as avoidance behaviour and suppressive behaviour, are discussed. The presence of both deconditioning-related physiological changes, such as muscle atrophy, changes in metabolism, osteoporosis and obesity as well as deconditioning related functional changes, such as a decrease in cardiovascular capacity, a decrease in muscle strength and impaired motor control in patients with CLBP are discussed. Results of studies on the level of physical activities in daily life (PAL) and the level of physical fitness in patients with CLBP compared to healthy controls were reviewed. In studies on PAL results that were either lower or comparable to healthy subjects were found. The presence of disuse (i.e., a decrease in the level of physical activities in daily life) in patients with CLBP was not confirmed. The inconclusive findings in the papers reviewed may partly be explained by different measurement methods used in research on PAL in chronic pain. The level of physical fitness of CLBP patients also appeared to be lower or comparable to the fitness level of healthy persons. A discriminating factor between fit and unfit patients with back pain may be the fact that fit persons more frequently are still employed, and as such may be involved more in physical activity. Lastly some suggestions are made for further research in the field of disuse and deconditioning in CLBP.

Effect of patient characteristics on reported outcomes after total knee replacement

OBJECTIVE

To evaluate the effect of pre-intervention factors in patient-reported outcomes at 6 months post-operatively following total knee replacement.

METHODS

A prospective observational study was carried out using two questionnaires sent to patients while they were on the waiting list for surgery: a generic questionnaire, the Medical Outcomes Study Short Form-36 (SF-36), and a specific questionnaire, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Six months after intervention, patients again received the same questionnaires. The dependent variables were the scores of the three domains of the WOMAC and the eight domains of the SF-36.

RESULTS

We recruited 640 patients. The mean age was 71 yrs and 73.6% of the patients were females. The multivariate analysis, in which the pre-intervention scores for each domain were added as covariates, showed that the most significant pre-intervention predictors were the baseline scores of each domain. Besides that, the social support, low back pain and the baseline score of the mental health domain (SF-36) were the pre-intervention predictors in the three WOMAC domains. With regard to the SF-36 domains the main predictors were the baseline mental health score, comorbidities, low back pain and social support.

CONCLUSIONS

The main predictor of outcome at 6 months post-operatively in all eleven domains was the pre-intervention score of each domain. Presence of social support, absence of low back pain and higher baseline SF-36 mental health score were related to the improvement in the health-related quality of life post-operatively.

Fear avoidance and prognosis in back pain: a systematic review and synthesis of current evidence

OBJECTIVE

Fear of pain, which is hypothesized to result in avoidance behavior, has been described as an obstacle to recovery in populations of patients with low back pain. However, the evidence to support the link between high levels of fear at early stages of pain and poor prognosis has yet to be systematically assessed. We undertook this review to explore current evidence and to propose further development of theoretical models.

METHODS

We performed a systematic literature review of all prospective inception cohorts of patients with acute low back pain that measured fear of pain (often described as fear avoidance) at baseline.

RESULTS

We reviewed 9 studies reported between 2001 and 2006. Several of these had acceptable/good methodology. Three studies, of which at least 1 had excellent methodology, showed no link between measures of fear at baseline and poor prognosis in the short term (3 months) or the long term (12 months). Three studies with acceptable methodology showed weak evidence for such a link, but the effect sizes were small. The only study with acceptable methodology to find a clear link suggested that fear of movement was linked to long-term pain.

CONCLUSION

Despite the prevalent focus on fear of pain at early stages of back pain, there is little evidence to link such fear states with poor prognosis. There is some evidence to suggest that fear may play a role when pain has become persistent. There is a growing consensus that distress/depression plays an important role at early stages, and clinicians should focus on these factors.