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Biomedical subjects

A K Burton

Publications and source records attributed to A K Burton.

At least 19 recordsLinked to original sources
PubMed1998

Clinical guidelines in the management of low back pain.

With the emergent concept of evidence-based practice, various countries have produced clinical guidelines for the management of acute low back pain since 1993-94. By and large the evidence-base for these proposals is consistent, though over the last 4 years it has increased considerably, and there has been a slight change of emphasis in several aspects. As all the guidelines are based on the same evidence, the similarity between them is not surprising. The common features are diagnostic triage along with periodic assessment to guide management strategies. There has been progressive reduction in the recommendation of rest as a treatment option, and early activation is increasingly recognized as a potent intervention. There has been a progressive recognition that psychosocial factors are important determinants for the risk of chronicity, and that such factors need to be addressed clinically. Specific therapeutic recommendations vary, but these are probably less important than the overall strategy. It is obviously hoped that clinical management should improve as a result of these initiatives, but effective dissemination and implementation are persisting concerns, and the effectiveness of clinical guidelines in changing clinical practice is still unproven.

Acute Disease↗
PubMed1997

Back injury and work loss. Biomechanical and psychosocial influences.

The exponential increase in occupational low back pain disability is a problem that is not being addressed adequately in clinical practice. The notion of achieving primary control through ergonomic intervention, based on biomechanics principles, has so far been unhelpful. The traditional secondary prevention strategies of rest and return to restricted work duties are seemingly suboptimal. Biomechanics/ergonomic considerations may be related to the first onset of low back pain, but there is little evidence that secondary control based solely on these principles will influence the risk of recurrence or progression to chronic disability. More promising in this respect are programs that take account of the psychosocial influences surrounding disability. Work organizational issues are clearly important, but so also is the behavior of clinicians. The balance of the available evidence suggests that clinicians generally should adopt a proactive approach to rehabilitation by recommending, whenever possible, early return to normal rather than restricted duties as well as complementary psychosocial advice if the issue of chronic disability is to be successfully tackled.

Back Injuries↗
PubMed1997

Is ergonomic intervention alone sufficient to limit musculoskeletal problems in nurses?

This study retrospectively surveyed 1,216 nurses at hospitals in Belgium and The Netherlands. Data concerning workloads, musculoskeletal symptoms, work loss and psychosocial factors were collected by questionnaire. Lifetime prevalence rates for musculoskeletal problems and low back trouble were significantly lower in the Dutch hospitals than the Belgian hospitals, but a significantly higher proportion of Dutch nurses had 'heavy' workloads. Overall, symptoms and work loss in the previous 12 months were not related to workload, nor was the perception that work was causative; a change of duties because of symptoms was rare (< 3%). The Dutch nurses differed strikingly from Belgian nurses on the psychosocial variables; they were less depressed and significantly more positive about pain, work and activity. It is proposed that ergonomic interventions alone may be sub-optimal in controlling musculoskeletal problems among nurses. The additional provision of psychosocial information to challenge misconceptions and encourage self-management is proposed.

Adaptation, Psychological↗
PubMed1996

Occupational risk factors for the first-onset and subsequent course of low back trouble. A study of serving police officers.

STUDY DESIGN: A survey of occupational risks for low back trouble in two police forces discordant for one known physical stressor (wearing body armor weighing approximately 8.5 kg. OBJECTIVES: To determine the hazard for first-onset and subsequent course of low back trouble associated with occupational physical and psychosocial stressors. SUMMARY OF BACKGROUND DATA: Various occupational physical stressor have been associated with the prevalence of back pain, but their relationship with first-onset low back trouble is uncertain. Psychosocial factors reportedly are important determinants of chronicity. METHODS: Anamnestic data on low back trouble were collected from representative random samples of "exposed" and control forces, along with variables describing exposure to occupational physical stressors and sports results. Psychometric tests were administered. RESULTS: Occupational risk factors for first-onset low back trouble were determined from lifetables based on officers with no previous back pain history. Survival time to first onset was affected adversely by wearing body armor and, less so, by vehicular exposure and sports participation. The proportion with persistent (chronic) trouble did not depend on length of exposure since onset, but longer service was associated with recurrent episodes. Chronicity was related to distress and blaming police work. Work loss was associated with blaming work and wearing body armor. Changing to lighter duties after development of low back trouble occurred rarely. CONCLUSIONS: Exposure to occupational physical stress seems detrimental; It reduced survival time to first-onset of low back trouble. Recurrence was associated with time since onset, but persistent trouble was not. Sports participation was a risk if occupational hazards were high.

Adult↗
PubMed1996

The natural history of low back pain in adolescents.

STUDY DESIGN: A 5-year longitudinal interview and questionnaire-based survey of back pain in adolescents. OBJECTIVES: To determine the natural history of back pain during adolescence in boys and girls and to explore the influence of sports participation and lumbar flexibility. SUMMARY OF BACKGROUND DATA: Previous data on low back pain and flexibility in adolescents have come largely from cross-sectional studies with differing definitions and age groups. A longitudinal study would offer a more detailed description of aspects of the natural history of back pain. METHODS: A cohort of 216 11-year-old children was given a structured questionnaire about back pain. Follow-up evaluation was annual for 4 more years. Lumbar sagittal mobility was measured in first and last years. Life-table analysis was the chosen statistical method. RESULTS: Annual incidence rose from 11.8% at age 12+ to 21.5% at 15+ years. Lifetime prevalence rose from 11.6% at age 11+ to 50.4% at age 15+ years. Experience of back pain was frequently forgotten. Recurrent pain was common, usually manifesting as such rather than as progression from a single episode; few children required treatment. Back pain was more common in boys than girls, especially by age 15 years. There was a positive link between sports and back pain only for boys. Severity and flexibility were not related to sex, treatment, or sport. CONCLUSIONS: Back pain in adolescents is common; it increases with age and is recurrent, but in general does not deteriorate with time. Much of the symptomatology may be considered a normal life experience, probably unrelated to adult disabling trouble.

Adolescent↗
PubMed1996

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.

Absenteeism↗
PubMed1996

Low back pain in children and adolescents: to treat or not?

Recent cohort data has shown that low back pain is a common symptom in adolescents that, by the age of 16, approaches the level found in adults. The symptoms are frequently recurrent, but are not usually associated with disability. Spells are frequently forgotten, and medical attention is not generally sought. Although the possibility of serious spinal pathology must be considered, the majority of adolescent back trouble may be considered a normal life experience. The efficacy of treatment for non-specific back pain in this age group is undetermined, but the similarities with adult symptoms suggests that management should follow current clinical guidelines for adults (early activation and advice stressing the benign nature of the problem). Persisting root pain may best respond to chemonucleolysis. There is no evidence that treatment or lifestyle changes at this age will reduce symptoms in adult life, but inappropriate medical attention may have detrimental psychosocial consequences.

Adolescent↗
PubMed1996

Patient educational material in the management of low back pain in primary care.

Distributing educational material about low back pain to patients is increasingly seen as a possible adjunct to clinical management and a potential means of reducing the risk of the progression of the disorder toward chronic disability. Most back pain is managed in the primary care setting, where such material could save time and support the efforts of these practitioners. Recent evidence-based clinical guidelines for acute low back pain in U.S. and U.K. have advocated the use of educational material, but most of the available booklets are based on traditional biomedical theory about back pain and are neither evidence-based nor in line with recent guidelines. The few of these booklets that have been tested have had inconsistent effects. A new booklet has been developed which is evidence-based, in line with recent guidelines, and states its messages in a firm, uncluttered, and unambiguous manner. Preliminary studies show that it is readily accepted by patients, that they understand the messages, and that it creates a positive shift in beliefs about low back pain. Further studies regarding the use of this booklet are required to determine its effect on clinical outcomes.

Humans↗
PubMed1996

Lumbar disc degeneration and sagittal flexibility.

It is uncertain whether intervertebral disc degeneration is associated with reduced or increased flexibility, although lumbar flexibility is known to reduce with advancing age. This cross-sectional study of 214 middle-aged men attempted to determine the influence on lumbar sagittal flexibility from intervertebral disc degeneration parameters measured from magnetic resonance images (disc height, signal intensity, bulging, osteophytes). Multivariate analyses showed that a reduced extent of lumbar flexibility could be accounted for by the combined effect of decreasing disc height together with increasing age, weight, and back pain frequency. Although it remains possible that single degenerate discs will display increased mobility, the presence of discs at various stages of degeneration results in a net reduction of flexibility. The factors studied here explained only 31% of the variance in flexibility; the major determinants remain to be identified and quantified.

Adult↗
PubMed1995

Absence resulting from low back trouble can be reduced by psychosocial intervention at the work place.

STUDY DESIGN: A 1-year prospective study in industry, assessing effects of an educational pamphlet on various psychosocial parameters and absenteeism resulting from low back trouble. OBJECTIVES: To determine the value of distributing an educational psychosocial pamphlet to reduce absenteeism resulting from back trouble. The pamphlet was designed to alter avoidance behaviors by encouraging a positive, active approach. SUMMARY OF BACKGROUND DATA: Attempts to control back-pain disability have failed. Fear of pain and activity seemingly leads to avoidance behaviors than contribute to chronicity and work loss. Avoidance behaviors are mediated by attitudes and beliefs; such attitudes and beliefs are a reasonable target for educational interventions designed to change "inappropriate" behaviors (e.g., extended absenteeism). Health education pamphlets are advocated widely but tested rarely. METHODS: Three factories participated in the study. Psychosocial data were collected by questionnaires; absence data were extracted from company records. A psychosocial pamphlet was distributed in one factory; the control subjects received either a nonspecific pamphlet or no intervention. The pamphlet emphasized a positive approach to low back trouble (reduction of negative beliefs and attitudes). RESULTS: In the company whose employees received pamphlets, a significant reduction occurred for the number of spells with extended absence and the number of days of absence (70% and 60%, respectively) compared with extrapolated values. A concomitant positive shift in beliefs concerning the locus of pain control and the inevitable consequences of low back trouble was found. CONCLUSION: A simple industrial intervention using a psychosocial pamphlet, which was designed to reduce avoidance behaviors by fostering positive beliefs and attitudes, successfully reduced extended absence resulting from low back trouble.

Absenteeism↗
PubMed1995

Psychosocial predictors of outcome in acute and subchronic low back trouble.

STUDY DESIGN: A prospective survey of patients seeking primary care for low back pain. Clinical and psychosocial data, available at presentation, were explored for predictors of outcome at 1 year. OBJECTIVES: To determine the relative value of clinical and psychosocial variables for early identification of patients with a poor prognosis. SUMMARY OF BACKGROUND DATA: Current treatment strategies for low back pain have failed to stem the rising levels of disability. Psychosocial factors have been shown to be important determinants of response to therapy in chronic patients, but the contribution from similar data in acute or subchronic patients has not been comprehensively investigated. METHODS: Two hundred fifty-two patients with low back pain, presenting to primary care, underwent a structured clinical interview and completed a battery of psychosocial instruments. Follow-up was done by mail at 1 year; outcome was measured using a back pain disability questionnaire. Predictive relationships were sought between the data at presentation and disability at follow-up. RESULTS: Most patients showed improved disability and pain scores, although more than half had persisting symptoms. Eighteen percent showed significant psychological distress at presentation. Multiple regression analysis showed the level of persisting disability to depend principally on measures in the psychosocial domain; for acute cases outcome is also dependent on the absence or presence of a previous history of low back trouble. Discriminant models successfully allocated typically 76% of cases to recovered/not-recovered groups, largely on the basis of psychosocial factors evident at presentation. CONCLUSIONS: Early identification of psychosocial problems is important in understanding, and hopefully preventing, the progression to chronicity in low back trouble.

Acute Disease↗
PubMed1994

Continuous measurement of lumbar posture using flexible electrogoniometers.

Continuous measurement of changing limb segment angle is possible using a recently introduced flexible electrogoniometer but, unfortunately, the magnitude of linear displacements occurring during flexion and extension of the trunk has prevented its use as a measure of spinal mobility and posture. To overcome this limitation, a specially constructed, lightweight, aluminium carriage has been developed to allow free linear travel of the electrogoniometer, while maintaining the angle recorded between the thoracolumbar junction and the sacrum. The reliability and practicability of this new approach for recording changes in lumbar posture have been investigated. Following bench tests and operator training, measurements of maximal flexion and extension of the lumbar spine were repeated on 12 subjects. The extent of sagittal mobility was compared with measures from a fluid-filled inclinometer and a flexicurve. Analysis of the data showed that the use of the aluminium carriage did not markedly influence the accuracy of the electrogoniometer, and the technique as modified was found to be comparable with standard techniques for estimating the extent of lumbar sagittal flexibility. A field based study, involving four garage mechanics, was undertaken to examine the usability and acceptability of the electrogoniometer technique for continuous measurements. Lumbar curvature was monitored continuously for a two hour period during the course of the mechanics' working day. Dedicated software provided angle-time plots from which it was established that extreme flexed or extended postures were maintained only for relatively short periods; projection to an eight hour shift would indicate that a total of approximately 40 min is spent in extension beyond 10 degrees and flexion beyond 50 degrees. The technique has the potential to provide quantitative information on lumbar posture necessary for non-invasive, biomechanical investigations of spinal loading. It will be particularly useful for both sporting and occupational ergonomics field-studies.

Adult↗
PubMed1994

Estimation of spinal loads in overhead work.

To explore the spinal loads occurring in overhead working postures and to assess the value of ergonomic reduction of lumbar extension, spinal strain was measured by stature change in simulated motor vehicle maintenance tasks. A field study identified the typical extent of lumbar extension incurred in this type of work. In the laboratory eight male volunteers tightened and loosened bolts both overhead and at chest-height for 30 min periods; records were made of lumbar posture, ground reaction force, and perceived exertion. Stature change was measured using a refined technique which permitted estimation of net effect of the work loads. The field study revealed that motor mechanics typically spent 8% of their time working overhead with up to 10 degrees of lumbar extension. In the laboratory study, the overhead task entailed more lumbar extension and perceived exertion than did the chest-height task; ground reaction forces did not differ substantially between tasks. Only small changes in stature were observed at the end of the work period, and there was no significant difference between the tasks (means: overhead, +0.61 mm; chest-height, -0.23 mm: p = 0.31). Stature change was significantly correlated with lordosis for overhead work such that increased lordosis (compared with chest-height work) was associated with relative stature gain. No evidence was found to indicate a need for ergonomic intervention in overhead work tasks so far as spinal loading is concerned. The lack of substantial change in stature from tasks perceived to involve moderately high levels of exertion was unexpected; it would appear that some elements of dynamic work tasks may have a relative unloading effect, and that lordotic postures reduce load on the spinal discs.

Biomechanical Phenomena↗
PubMed1991

Does leisure sports activity influence lumbar mobility or the risk of low back trouble?

In order to look for relationships between leisure sports activity and both low back trouble and back flexibility, 958 people, aged 10-84 years, were examined. Their history of low back trouble and leisure sports participation was recorded, together with measurements of maximal lumbar sagittal mobility. No evidence was found to suggest that the extent of sports participation either during childhood or as an adult was related to the development, frequency, or onset-age of low back trouble. Although sports participation was not associated with flexibility in schoolchildren, adults who had continued leisure sports for greater than 5 years showed relatively reduced lumbar mobility. On the basis of the results presented here, it is concluded that sporting pursuits at amateur/leisure level do not, in themselves, represent a major risk factor for low back trouble. On the contrary, it was found that adults typically continued leisure sports participation for some years after developing low back trouble. Sports participation, in general terms, is not contraindicated for those who have experienced low back trouble, but regular exercise does not apparently result in increased lumbar flexibility.

Adolescent↗
PubMed1991

Prediction of the clinical course of low-back trouble using multivariable models.

The inability to predict outcome in patients with low-back pain seriously impedes clinical trials and leads to inappropriate or unnecessary treatment. This prospective study investigated the value of multivariable mathematical models to predict the 1-year clinical course of 109 patients with low-back trouble (LBT). Discriminant analysis was used to determine predictive models for outcome groups at 1 month, 3 months and 1 year. The variables selected in the analyses were subsets of 29 items from a clinical interview at presentation. These included anamnestic features of the first episode as well as symptomatic details and results from clinical tests for the current spell. The derived models successfully discriminated outcome groups with estimates of sensitivity and specificity ranging from 63 to 99%. When models from one set of patients were tested for predictive accuracy by the application of them to a different set, nonrecovery and satisfactory improvement were predicted with a 76-100% success rate. The results affirmed the importance of considering combinations of interrelated variables for prediction and discrimination in LBT. This work has demonstrated that outcome can be predicted successfully by the use of mathematic models based just on presentation data. The ability to determine homogenous groups in respect to outcome is seen as an important aid to therapeutic research; further work will enable refinement of these models for general clinical use and for incorporation into computer-based interview systems.

Adult↗
PubMed1991

Noninvasive measurement of lumbar sagittal mobility. An assessment of the flexicurve technique.

The use of flexicurves to measure lumbar sagittal mobility was subjected to a series of reliability and validation experiments. Appropriate statistical methods were described and used to quantify intraobserver and intrasubject variability and to determine limits of agreement with measurements from radiographs. It was shown that the traditional use of correlation coefficients can produce misleading or inadequate information. The flexicurve technique had an intraobserver variability of 3-4 degrees of movement, was not significantly influenced by intrasubject variability, and provided measurements typically within 6 degrees of radiographic measurements. The data suggest that the flexicurve technique is less biased than the inclinometric method. These results demonstrate the use of suitable statistical methods to assess the clinical usefulness, or level of interchangeability, of spinal measurement instruments.

Biomechanical Phenomena↗
PubMed1990

Lumbar sagittal mobility and low back symptoms in patients treated with manipulation.

The relationship between lumbar sagittal mobility and symptoms was explored in a 1-year prospective study of 55 patients undergoing manipulative treatment. A significant increase in mean mobility was found to occur in the 1st month, together with a concomitant significant decrease in mean pain values; symptoms continued to decrease thereafter, but mobility remained unchanged. More detailed analysis of the data revealed that symptomatic improvement was as common in patients with unaltered or reduced mobility as it was in those who showed an increase; changes in mobility at 1 month had no predictive value for symptomatic status at 1 month or 1 year. It is concluded that if any benefits actually result from manipulative therapy they are not a direct function of increased overall lumbar sagittal mobility. It remains possible that manipulation may influence other mobility parameters, such as coupled motions, so future studies should be directed toward investigation of three-dimensional movement patterns.

Adult↗