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PubMedDate not supplied

Effects of gold and silver backings on the dose rate around an 125I seed.

Measurements of the effect of either gold or silver backing on the dose rate around an 125I seed were performed using a Therados RFA7 dosimetry system and a small diode detector which was 2.5 mm in diameter and 0.06 mm thick. It was found that the presence of the gold or silver backing modifies the diode response on the side of the 125I seed away from the backing. The effect depends on the backing material and the distance from the seed. There is a small increase close to the gold backing but a decrease further away. This decrease at distances greater than 10 mm from the seed is uniformly 10%, the same as found when the seed is backed by air. There is an increase of up to 25% observed with silver backing the seed and this increase remains significant more than 30 mm from the seed. When the response increases, the results are hard to interpret quantitatively because of variations in the diode response per unit dose with photon energy and extreme sensitivity to geometric changes. Nonetheless, except for the increase at close distances with the gold, the results are in agreement with EGS4 Monte Carlo photon transport simulations which are for a simplified geometry and account for x-ray fluorescence from the K-shell. Furthermore, the increase in the gold-backed case is qualitatively explained by Williamson's Monte Carlo calculations which take into account the L-shell fluorescent x-rays from gold.

Brachytherapy↗
PubMed2000

3 year simvastatin treatment and lens nuclear back scattering.

AIM: To determine if 3 year treatment of hypercholesterolaemia with simvastatin causes an increase of lens nuclear back scattering. METHODS: 160 patients with hypercholesterolaemia in the Scandinavian Simvastatin Survival Study (4S) were followed for 3 years. Half (80) of the patients took simvastatin and half (80) received placebo. The lens was photographed with a Topcon SL-45 slit lamp camera at the beginning and at 1 year intervals. A common lens nuclear area was used for measuring lens nuclear back scattering. RESULTS: Nuclear back scattering increased with age and there was more pronounced scattering in women than in men. Lens nuclear back scattering did not differ significantly between the simvastatin and placebo groups, but the power was low (0.2). Lens nuclear back scattering increased during the study period independently of baseline back scattering, age, and sex for both groups. CONCLUSION: Although no significant difference was found between the simvastatin and placebo groups, the currently available data are insufficient for exclusion of the possibility that taking simvastatin during a 3 year period increases nuclear back scattering. However, a possible minor increase of nuclear back scattering is clinically irrelevant considering known beneficial effects of simvastatin on coronary heart disease.

Adult↗
PubMed1970

Increased ureteral back pressure enhances renal tubular sodium reabsorption.

Moderate increases of ureteral back pressure usually cause decreases of glomerular filtration rate and even greater decreases of sodium excretion. It has been assumed previously that increased ureteral back pressure does not enhance renal tubular sodium reabsorption directly and that the decreases of sodium excretion are caused by the decreases of glomerular filtration rate. In the experiments reported here, the effect of increased ureteral back pressure on urinary sodium excretion was studied in dogs in which changes of filtration rate were minimized by infusing saline while ureteral back-pressure was increased. When ureteral back pressure was increased on one side by 10-23 cm of water, the inulin clearance of the experimental kidney decreased by only 3-12% in 21 experiments, did not change significantly (+/-2%) in eight experiments, and increased by 3-8% in seven experiments. The sodium excretion of the experimental kidney decreased in all experiments regardless of whether its inulin clearance increased, decreased, or was unchanged from control values. When the inulin clearance of the experimental kidney increased or remained unchanged during increased ureteral back pressure, its reabsorption of sodium increased more than could be accounted for by the increase of filtered sodium. When the inulin clearance of the experimental kidney decreased during increased ureteral back pressure, its reabsorption of sodium decreased less than could be accounted for by the decrease of filtered sodium.Therefore, the effect of increased ureteral back pressure to decrease urinary sodium excretion is caused in part by increased tubular reabsorption of sodium.

Animals↗
PubMed1990

Total knee replacement: radiologic findings in failure of porous-coated metal-backed patellar component.

One technique for replacing the articular surface of the patella in total knee replacement is the use of a cementless porous-coated metal-backed polyethylene component. Anteroposterior, lateral, and Merchant or skyline radiographs in 10 cases of porous-coated metal-backed components that failed were evaluated for component alignment, component displacement, radiolucencies, loose beads, and integrity of the patellar component. Component failure was documented by surgery in all 10 cases. Seven cases of failure involved the patellar pegs or junction of the pegs with the metal backing and three cases involved the polyethylene portion. In the seven cases of peg-metal backing failure, three cases showed loose beads before failure and seven cases showed displacement of the metal backing at time of failure. All three cases of polyethylene failure showed narrowing or displacement of the polyethylene portion. Our experience shows that displacement of the metal backing, displacement of the polyethylene, and disruption of patellar pegs are seen in failed porous-coated metal-backed patellar components. Loose beads may be seen before peg-metal backing failure.

Humans↗
PubMed1997

Managing Back Pain During Pregnancy.

The incidence of low-back pain during pregnancy is thought to be about 50%. It occurs most commonly after the sixth month and can last until the sixth month postpartum. The major predictors are back pain prior to pregnancy and multiparity. Several biomechanical and physiologic changes during pregnancy contribute to back pain. As the woman's abdominal muscles are stretched and tone is diminished, they lose their ability to contribute to neutral posture. During pregnancy, production of the hormone relaxin increases ten-fold. The hormone creates joint laxity, which not only allows the pelvis to accommodate the enlarging uterus, but also weakens the ability of static supports in the lumbar spine to withstand shearing forces. In the pelvis, joint laxity is most prominent in the symphysis pubis and the sacroiliac joints. On physical exam, neither lumbar nor sacroiliac back pain is generally associated with any evidence of neurologic deficit or hip pathology. In cases of lumbar back pain, the physical exam will be most consistent with discogenic pain and/or facet element pain. Therefore, a pregnant woman's pain may be most pronounced on flexion and standing. Among the tests that can be used to evaluate lower-back pain are the posterior pelvic provocation test; ventral gapping test; dorsal gapping test; sacroiliac joint fixation test; Patrick's test, or FABERE's maneuver (flexion, abduction, external rotation, and extension); and Derbolowski's test. The most common types of back pain during pregnancy are lumbar pain, sacroiliac pain, and nocturnal back pain.

Journal Article↗
PubMed1998

The feed-back regulation of erythropoietin production in healthy humans.

The proposed oxygen-dependent feed-back loop regulation of EPO production (Fogh 1978, Erslev 1991, LeHir et al 1991, Nielsen 1991) is mainly supported by data from studies in animals and cell cultures. The feed-back loop and its dependence on oxygen was therefore challenged by studies in healthy humans: Exposure of humans to different levels of acute and continued altitude hypobaria provided evidence for an oxygen dependency of the EPO response. This response is consistent with the proposed feed-back loop regulation of EPO production. Exposure to continued altitude hypobaria demonstrated that the decline in human EPO production is initiated before an EPO-induced erythropoiesis is detectable, and that this decline is related to a concomitant decrease in the haemoglobin-oxygen affinity. Contrary to the feed-back loop, this time-relation indicate that the feed-back regulation of EPO production during continued hypobaric hypoxia is exerted primarily through a decrease in the haemoglobin-oxygen affinity, rather than by the effects of an EPO-stimulated erythropoiesis. A laboratory experiment demonstrated that the lowering of PaO2 by short-term breathing of hypoxic gas could trigger human EPO production. Since the possible influence of spontaneous non-hypoxic variations in EPO production was taken into account, the magnitude of the human EPO response to hypoxia was found to be less than formerly observed in humans and rodents. Contrary to former observations in rodents, the triggering of human EPO production was not related to a hypoxic or normoxic increase of the haemoglobin-oxygen affinity, and normocapnia, without changes in pH or haemoglobin-oxygen affinity, sufficed to suppress the human EPO response to hypoxia. Together with the altitude studies, these results have demonstrated that human EPO production is dependent on, and triggered by, oxygen deprivation, and that changes in the haemoglobin-oxygen affinity play a role mainly in the feed-back regulation rather than in the triggering of human EPO production. Increased circulating levels of the proinflammatory cytokine IL-6 was found in healthy humans during four days of altitude exposure as compared with sea level. The other proinflammatory cytokines IL-1 beta, and TNF alpha remained unchanged, and the increased serum IL-6 did not induce production of c-reactive protein. However, a relation was shown between serum IL-6, SaO2, and serum EPO. These observations in humans confirm earlier in vitro studies in that IL-6 may have a co-stimulatory role on EPO production in the presence of hypoxia. Comparable circadian variations in human EPO production were shown in sedentary subjects, athletes, and healthy but hypoxaemic subjects. Human EPO production could not be triggered by one hour of high-intensity exercise, whereas longitudinal changes in exercise showed a trend of relation between human EPO production, serum concentration of free testosterone, and indices of body composition. These results have demonstrated an endogenous, probably hormonal, and oxygen-independent regulation of human EPO production, which is at variance with the oxygen dependent feed-back loop regulation of EPO production. Conclusively, the present investigations have shown that the feed-back loop regulation of EPO production, as described by studies in rodents and cell-culture models, cannot be applied to the physiology of human EPO production without modifications.

Animals↗
PubMed1998

Urodynamic verification of noninvasive back-pressure recordings from the urinary bladder.

Obstructive voiding is best evaluated with urodynamics, especially simultaneous measurement of bladder-pressure and urine flow rates. As an alternative to catheterization for urodynamics, noninvasive back-pressure methods using an external condom system have been introduced. This device uses one side tube in the condom for pressure recording and an outlet tube that is clamped for short periods of time during voiding. However, there have been problems with accurate back-pressure recording, including leaking, clamping techniques, hydrostatic pressures associated with pressure recording below the level of the symphysis pubis, and assessment of back pressures in relation to bladder and detrusor pressures. To address these issues, we have modified the condom for passing a catheter into the urethra for simultaneous direct bladder and back-pressure recording. The clamping device on the outlet tube also has been modified to produce back flushing of urine in addition to clamping. Hydrostatic issues have been addressed by making pressure recordings at the level of the symphysis pubis. Seven patients with obstructive symptoms were evaluated using these new devices. Back pressures were not statistically different than detrusor pressures recorded with a urethral catheter. Thus, the modifications have improved back-pressure recording techniques. The use of noninvasive back-pressure recording may be an important adjunct in the evaluation of obstructive uropathy.

Condoms↗
PubMed2004

Can cardiopulmonary resuscitation injure the back?

Cardiopulmonary resuscitation (CPR) is performed frequently by nurses in general hospitals and often in compromised positions. This may induce injury to the rescuer's spine particularly if the CPR procedure is continued for a considerable time before medical staff arrive. Back pain as an occupational symptom in nurses has received considerable attention in the medical literature, but there is no report on the effect of CPR on back discomfort. This article reports a survey of the CPR experience of nurses in general hospitals and nursing homes and explores the difficulties encountered by nurses during the CPR procedure. A questionnaire was sent to nurses who had CPR experience in three general hospitals and 20 nursing homes through the nursing administrators of the respective units. Analysis of 205 completed questionnaires showed that the duration of the CPR procedure could last up to 27 min. While 86% of the nurses performed CPR on a bed, 70% of them had their legs hanging over the edge of the bed without support and 55% had to turn their head or back to look at the ECG monitor during the procedure. Over 80% experienced back discomfort during or after the CPR procedure and 56% considered their back discomfort was related to the duration of the procedure. Twenty percent of the nurses suffered back injury or prolapsed disc and over 40% of these 'injured' nurses considered their back injury was related to or aggravated by CPR. Results of this survey suggest there is a need to review the support given to nurses to ensure safe administration of the CPR procedure in the general ward environment.

Back Injuries↗
PubMed1997

A controlled trial of an educational program to prevent low back injuries.

BACKGROUND: Low back injuries are common and costly, accounting for 15 to 25 percent of injuries covered by workers' compensation and 30 to 40 percent of the payments made under that program. The high costs of injury, the lack of effective treatment. and the evidence that there are behavioral risk factors have led to widespread use of employee education programs that teach safe lifting and handling. The effectiveness of those programs, however, has received little rigorous evaluation. METHODS: We evaluated an educational program designed to prevent low back injury in a randomized, controlled trial involving about 4000 postal workers. The program, similar to that in wide use in so-called back schools, was taught by experienced physical therapists. Work units of workers and supervisors were trained in a two-session back school (three hours of training), followed by three to four reinforcement sessions over the succeeding few years. Injured subjects (from both the intervention and the control groups) were randomized a second time to receive either training or no training after their return to work. RESULTS: Physical therapists trained 2534 postal workers and 134 supervisors. Over 5.5 years of follow-up, 360 workers reported low back injuries, for a rate of 21.2 injuries per 1000 worker-years of risk. The median time off from work per injury was 14 days (range, 0 to 1717); the median cost was $204 (range, zero to $190,380). After their return to work, 75 workers were injured again. Our comparison of the intervention and control groups found that the education program did not reduce the rate of low back injury, the median cost per injury, the time off from work per injury, the rate of related musculoskeletal injuries, or the rate of repeated injury after return to work; only the subjects' knowledge of safe behavior was increased by the training. CONCLUSIONS: A large-scale, randomized, controlled trial of an educational program to prevent work-associated low back injury found no long-term benefits associated with training.

Adolescent↗
PubMed1996

Prevalence of back pain and characteristics of the physical workload of community nurses.

A research project is described that analyses the back pain prevalence and physical working conditions of community nurses. The purpose was to compare the position of nurses working in institutional care with the specific situation of nurses working in the private homes of their patients. The results of a questionnaire showed that the back pain prevalence was relatively high as compared to other occupations and also when compared to other health care sectors. The home care organization is influenced not only by sick leave due to back pain, but also its efficiency is hampered by nurses with back pain who continue to work. It appeared that the total sick leave incidence due to musculoskeletal disorders other than back pain exceeds that due to back pain alone. The physical exposure level not only consisted of frequent and heavy lifting and transferring of patients but also a substantial static workload was present. The onset of back pain seems to result from a gradual build up of overload reaching its maximum. A preventive approach should take these differential loading factors into account. The consequences for preventive interventions are discussed resulting in recommendations towards a (participatory) ergonomic approach. This material forms the baseline of a controlled prospective trial in home care.

Adult↗
PubMed2000

Validity of the modified back-saver sit-and-reach test: a comparison with other protocols.

PURPOSE: Studies have shown that the classical sit-and-reach (CSR) test, the modified sit-and-reach (MSR), and the newly developed back-saver sit-and-reach (BS) test have poor criterion-related validity in estimating low-back flexibility but yielded moderate criterion-related validity in hamstring flexibility. The V sit-and-reach (VSR) test was found to be practical but the validity has not been established. The purpose of this study was to propose a modified back-saver sit-and-reach (MBS) test, which incorporated all advantages of the various protocols, and to compare the criterion-related validity and reliability of all these tests. METHODS: 158 college students (F = 96, and M = 62; age = 20.77 +/- 2.51) performed CSR, VSR, BS (left and right leg), and MBS (left and right leg) tests in a randomized order. Scores from each test were then correlated with the criterion measures. RESULTS: For all sit-reach tests, intraclass reliability (single trial) was very high (r = 0.89-0.98). MBS yielded significant and highest r with low-back and hamstring criterion for men (r = 0.47-0.67) and women (r = 0.23-0.54). The low-back and right hamstring validity of MBS for men were significantly (P < 0.01) higher than those from BS and CSR, whereas no differences in criterion-related validity were found between the MBS and other protocols in women. The ratings of perceived comfort among the sit-and-reach protocols were significantly different (P < 0.001) from each other. The rating for MBS was observed the most comfortable test as compared with other protocols. CONCLUSION: The MBS test is not only a reliable test for hamstring and low-back flexibility, it is also a more practical with improved validity for hamstring and low-back flexibility in men than previous protocols.

Adolescent↗
PubMed1991

Low-back injuries in a heavy industry. II. Labor market forces.

Trends in rates of low-back strains, low-back impact injuries, and non-low-back injuries among field employees of a petroleum drilling company, 1979-1985, were examined to investigate the relationship between economic factors and the incidence of low-back and other injuries. Economic indicators included the rate of resignations, a surrogate for turnover, and the rate of layoffs. Only lost-time low-back strain rates increased during times of worker layoffs. Non-low-back injury rates were highest during periods of high turnover and no layoffs. Although the increasing age of the work force and the anxiety generated by an industry-wide depression may have played a role, it is likely that the increase in lost-time low-back strain injuries was a worker response to possible layoff.

Accidental Falls↗
PubMed1996

Early prediction of chronic disability after occupational low back injury.

STUDY DESIGN: An inception cohort design was used to study a consecutive sample of back-injured workers. OBJECTIVE: To refine and to test the Vermont Disability Prediction Questionnaire's ability to indicate an individual's relative risk for chronic disability after occupational low back injury. SUMMARY OF BACKGROUND DATA: Although most back-injured workers return to work quickly, the minority who do not account for the majority of associated costs and health care. Early identification of workers at high risk for disability would facilitate intervention strategies. METHODS: During the study recruitment period, people aged 18-60 years reporting occupational low back injury to the Vermont Department of Labor and Industry within 11 days of onset were eligible. A Vermont Disability Prediction Questionnaire was mailed to the 442 subjects who could be contacted and who gave informed consent. One hundred sixty-three of the 166 subjects who completed and returned the questionnaire within 15 days of initial injury were telephoned 3 months later to determine work status. Those who returned the questionnaire were compared with those who would not consent or did not return the questionnaire in time according to age, sex, residence, wages, work hours per week, and length of employment. Employment status (inability to work because of low back pain) was evaluated by telephone interview 3 months after initial injury. RESULTS: The follow-up interviewer was blinded to the Vermont Disability Prediction Questionnaire scores. of the 163 subjects, 16 (10%) were not working because of low back pain. Using a simple dichotomous scoring system for 11 questionnaire items, a cut-off score of 0.48 identified 3-month postinjury work status, with 0.94 sensitivity and 0.84 specificity. CONCLUSIONS: The Vermont Disability Prediction Questionnaire is a brief, easily administered and scored tool for identifying back-injured workers at relative risk for chronic disability. Such early identification should increase the efficiency of disability prevention strategies by directing them toward people who need them most. The accuracy of the questionnaire needs to be tested in a variety of different clinical and socioeconomic settings.

Adult↗
PubMed2002

Biopsychosocial multivariate predictive model of occupational low back disability.

STUDY DESIGN: To establish outcome, 253 workers with subacute and chronic low back conditions were assessed with a comprehensive multimethod biopsychosocial protocol at baseline, 3 days after the initial examination, and 3 months later. OBJECTIVE: To validate empirically a biopsychosocial model for prediction of occupational low back disability. SUMMARY OF BACKGROUND DATA: Costs of low back occupational disability continue to spiral despite stabilization of low back injury rates. An empirically based model to predict occupational disability in workers with low back injuries is required. METHODS: Workers with subacute low back injuries (4-6 weeks after injury, n = 192) and those with chronic back pain (6-12 months after injury, n = 61) were the study participants. The biopsychosocial protocol included five groups of variables: 1) sociodemographic, 2) medical, 3) psychosocial, 4) pain behavior, and 5) workplace-related factors. Predictive validity was investigated through a 3-month follow-up assessment, at which time the return to work outcome was determined. Stepwise logistic regression models were developed to predict work status. RESULTS: The final integrated model consisted of variables from a wide biopsychosocial spectrum: vitality, health transition, feeling that job is threatened due to injury, expectations of recovery, guarding behavior, perception of severity of disability, time to complete walk, and right leg typical sciatica. CONCLUSIONS: The "winning" variables identified in the integrated model are dominated by cognitions, which are accompanied by disability behaviors. A cognitive-behavioral model with an adaptation-oriented rather than a pathology-oriented focus is favored for early intervention with high-risk workers since cognitions are amenable to change.

Adult↗
PubMed2003

Efficacy and safety of rofecoxib in patients with chronic low back pain: results from two 4-week, randomized, placebo-controlled, parallel-group, double-blind trials.

STUDY DESIGN: Two replicate, 4-week, randomized, double-blind, placebo-controlled, trials of rofecoxib 25 and 50 mg versus placebo for chronic low back pain. OBJECTIVES: To determine the efficacy and safety of two doses of rofecoxib compared to placebo in the treatment of chronic low back pain. SUMMARY OF BACKGROUND DATA: Although nonsteroidal anti-inflammatory drugs are commonly prescribed for chronic low back pain, their efficacy is unproven and toxicity can be serious. These studies evaluated the efficacy and tolerability of rofecoxib, a selective COX-2 inhibitor, in the treatment of chronic low back pain. METHODS: Patients with chronic low back pain were randomized 1:1:1 to rofecoxib 25 mg, 50 mg, or placebo once daily. Primary endpoint: Low Back Pain Intensity. Secondary endpoints: Pain Bothersomeness, Global Assessments of Response to Therapy, Global Assessment of Disease Status, Roland-Morris Disability Questionnaire, SF-12 Health Survey, Use of Rescue Acetaminophen, and Discontinuations Due to Lack of Efficacy. RESULTS: Combining both studies, 690 patients were randomized to placebo (N = 228), rofecoxib 25 mg (N = 233), or rofecoxib 50 mg (N = 229). Mean (+/- SD) age was 53.4 (+/- 12.9) years, pain duration 12.1 (+/- 11.8) years, 62.3% female. Both rofecoxib groups improved significantly. Mean differences from placebo in pain intensity were -13.50 mm, -13.81 mm (25, 50 mg doses) respectively (P < 0.001). Both regimens were superior to placebo in eight of nine secondary endpoints. Fifty mg provided no advantage over 25 mg. Both rofecoxib regimens were well tolerated, although 25 mg had a slightly better safety profile. CONCLUSIONS: Rofecoxib significantly reduced chronic low back pain in adults and was well tolerated.

Adolescent↗
PubMed2003

Back pain in children: no association with objectively measured level of physical activity.

STUDY DESIGN: A cross-sectional survey of 481 children aged 8-10 years and 325 adolescents aged 14-16 years obtained through a proportional two-stage cluster sample of children living in Odense, Denmark. OBJECTIVES: To investigate whether there are any associations between back pain and the level of self-reported physical activity, the level of self-reported physical inactivity, and the level of objectively measured physical activity. In addition, to test the validity of the self-reported physical activity data. SUMMARY OF BACKGROUND DATA: A sedentary lifestyle in children is believed to be harmful for the back, whereas moderate physical activities are supposed to be beneficial. There is no obvious epidemiologic evidence in favor of this concept. In none of the previous studies has the combined activity/inactivity pattern been investigated, nor has the amount of physical activity been measured objectively. METHODS: The associations and dose-response connections for back pain, mid back pain, and low back pain in the preceding month were studied in relation to self-reported physical activity and physical inactivity. In addition, an objective and validated method to measure the daily level of physical activity (the accelerometer) was used to establish the associations with the same outcome variables. The association between the level of self-reported activities and the accelerometer was investigated. RESULTS: The self-reported data resulted in mixed findings, but there were no associations between any of the three pain variables and the readings from the accelerometer, and no changes occurred after adjustment for age, gender, and puberty stage. There was a weak and inconsistent correlation (0.25) between the accelerometer readings and self-reported physical activity that nevertheless tested significantly for trend but none between the accelerometer readings and the level of self-reported physical inactivity. CONCLUSIONS: There is no obvious association between the objectively measured level of physical activity and back pain in children and adolescents. Simple self-reported levels of physical activity and inactivity cannot be used meaningfully on young people in back pain research.

Adolescent↗
PubMed2003

Muscle relaxants for nonspecific low back pain: a systematic review within the framework of the cochrane collaboration.

STUDY DESIGN: A systematic review of randomized and/or double-blinded controlled trials. SUMMARY OF BACKGROUND DATA: The use of muscle relaxants in the management of nonspecific low back pain is controversial. It is not clear if they are effective, and concerns have been raised about the potential adverse effects involved. OBJECTIVES: The aim of this review was to determine if muscle relaxants are effective in the treatment of nonspecific low back pain. METHODS: A computer-assisted search of the Cochrane Library (Issue 2, 2002), MEDLINE (1966 up to October 2001), and EMBASE (1988 up to October 2001) was carried out. These databases were searched using the algorithm recommended by the Cochrane Back Review Group. References cited in the identified articles and other relevant literature were screened. Randomized and/or double-blinded controlled trials, involving patients diagnosed with nonspecific low back pain, treated with muscle relaxants as monotherapy or in combination with other therapeutic methods, were included for review. Two reviewers independently carried out the methodologic quality assessment and data extraction of the trials. The analysis comprised not only a quantitative analysis (statistical pooling) but also a qualitative analysis ("best evidence synthesis"). This involved the appraisal of the strength of evidence for various conclusions using a rating system based on the quality and outcomes of the studies included. Evidence was classified as "strong," "moderate," "limited," "conflicting," or "no" evidence. RESULTS: Thirty trials met the inclusion criteria. Twenty-three trials (77%) were of high quality; 24 trials (80%) were on acute low back pain. Four trials studied benzodiazepines, 11 nonbenzodiazepines, and 2 antispasticity muscle relaxants in comparison with placebo. Results showed that there is strong evidence that any of these muscle relaxants are more effective than placebo for patients with acute low back pain on short-term pain relief. The pooled relative risk for nonbenzodiazepines versus placebo after 2 to 4 days was 0.80 (95% confidence interval: 0.71 to 0.89) for pain relief and 0.49 (95% confidence interval: 0.25 to 0.95) for global efficacy. Adverse events, however, with a relative risk of 1.50 (95% confidence interval: 1.14 to 1.98) were significantly more prevalent in patients receiving muscle relaxants and especially the central nervous system adverse effects (relative risk 2.04; 95% confidence interval: 1.23 to 3.37). The various muscle relaxants were found to be similar in performance. CONCLUSIONS: Muscle relaxants are effective in the management of nonspecific low back pain, but the adverse effects require that they be used with caution. Trials are needed that evaluate if muscle relaxants are more effective than analgesics or nonsteroidal anti-inflammatory drugs.

Controlled Clinical Trials as Topic↗
PubMed1985

[The back in everyday life].

The adaptation of man to an erect posture is the result of phylogenetic as well as ontogenetic evolution of the spinal structures and is largely responsible for the development of back pain. Apart from the specific conditions of overwork, a large number of physical activities and certain postures maintained over long periods of time can favour the development of back pain. The prevention of benign back pain therefore depends on a re-education of the correct use of the back. This can be performed in the form of individual prevention or in small groups of subjects suffering from back pain in whom a high risk activity can be isolated in order to direct the re-education. Primary prevention can also be considered in subjects not presenting back pain, consisting of a better knowledge of the back and its correct use.

Adaptation, Physiological↗