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PubMed2002

The effect of antidepressant treatment on chronic back pain: a meta-analysis.

BACKGROUND: Back pain is one of the most common problems in primary care. Antidepressant medication is often prescribed, especially for chronic back discomfort, to alleviate pain and restore the patient's ability to conduct activities of daily living. OBJECTIVE: To assess the efficacy of antidepressants in treating back pain in adults. METHODS: We searched the MEDLINE (1966-2000), PsycLit, Cinhal, EMBASE, AIDSLINE, HealthSTAR, CANCERLIT, the Cochrane Library (clinical trials registry and the Database of Systematic Reviews), Micromedex, and Federal Research in Progress databases and references of reviewed articles. Included articles were written in English and dealt with randomized placebo-controlled trials of antidepressant medication use among adults with chronic back pain. Two reviewers abstracted data independently. Two continuous outcomes, change in back pain severity and ability to perform activities of daily living, were measured. Study quality was assessed with the methods used by Jadad and colleagues, and data were synthesized using a random-effects model. RESULTS: Nine randomized controlled trials with 10 treatment arms and 504 patients were included. Seven treatment arms included patients with major depression. Patients had chronic back pain, averaging 10.4 years. Patients treated with antidepressants were more likely to improve in pain severity than those taking placebo (standardized mean difference, 0.41; 95% confidence interval, 0.22-0.61) but not in activities of daily living (standardized mean difference, 0.24; 95% confidence interval, -0.21-0.69). Patients treated with antidepressants experienced more adverse effects (22% vs 14%, P =.01) than those receiving placebo. CONCLUSION: Antidepressants are more effective than placebo in reducing pain severity but not functional status in chronic back pain.

Activities of Daily Living↗
PubMed2000

Bed rest for acute low back pain and sciatica.

BACKGROUND: Low back pain is a common reason for consulting a general practitioner, and advice on daily activities constitutes an important part in the primary care management of low back pain. OBJECTIVES: To assess the effects of bed rest for patients with acute low back pain or sciatica. SEARCH STRATEGY: We searched the Cochrane Musculoskeletal Group trial register, Cochrane Controlled Trials Register, MEDLINE, Embase, Sport, Scisearch, and reference lists of relevant articles. We also contacted authors of relevant articles. Date of the most recent searches: December 1998. SELECTION CRITERIA: We included all randomised studies or quasi randomised studies where at least one comparison group of adult patients with acute low back pain with or without radiation of pain below the knee was advised to rest in bed for at least two days and one group was not, or where comparison groups were advised to stay in bed for different lengths of time. The main outcomes of interest were pain, functional status, recovery and return to work. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected trials for inclusion, assessed the validity of included trials and extracted data. Investigators were contacted to obtain missing information. MAIN RESULTS: Nine trials with a total of 1435 patients were included. Five trials met all four validity criteria and were assessed to have low risk of bias, while four trials were assessed to have moderate to high risk of bias. Four trials compared bed rest with advice to stay active, and overall the results were heterogeneous. Overall results from two high quality studies indicate no difference in pain intensity at three weeks follow-up [Standardized Mean Difference 0.0 (95%CI: -0.3, 0.2)], and a small difference in functional status in favour of staying active [Weighted Mean Difference 3.2 (on a 0-100 scale) (95%CI 0.6, 5.8)]. Two high quality trials reported no differences in pain intensity between two to three days of bed rest and seven days of bed rest. Another two high-quality trials found no differences between bed rest and exercises in pain intensity or functional status. REVIEWER'S CONCLUSIONS: Bed rest compared to acvice to stay active will at best have small effects, and at worst might have small harmful effects on acute LBP. Differences in effects of advice to stay in bed compared with advice to stay active are small for patients with low back pain with or without sciatica. There is not an important difference in the effects of bed rest compared with exercises in the treatment of acute low back pain, or seven days compared with two to three days of bed rest in patients with low back pain of different duration with and without radiating pain.

Acute Disease↗
PubMed2002

Advice to stay active as a single treatment for low back pain and sciatica.

BACKGROUND: Low back pain is one of the most common conditions managed in primary care. Restricted activity, rest, and symptomatic analgesics are the most commonly prescribed treatment for low back pain and sciatica. OBJECTIVES: To assess the effects of advice to stay active as single treatment for patients with low back pain. SEARCH STRATEGY: Computerised searches in MEDLINE, EMBASE, Sport, The Cochrane Controlled Trials Register, Musculoskeletal Group's Trials Register and Scisearch, and scanning of reference lists from relevant articles were undertaken. Relevant studies were also traced by contacting authors. Date of the most recent searches: December 1998. SELECTION CRITERIA: We included all randomised trials or quasi-randomised trials where the study population consisted of adult patients with low back pain or sciatica, in which one comparison group was advised to stay active. The main outcomes of interest were pain, functional status, recovery and return to work. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected trials for inclusion, assessed the validity of included trials and extracted data. Investigators were contacted to collect missing data or for clarification when needed. MAIN RESULTS: Four trials, with a total of 491 patients, were included. Advice to stay active was compared to advice to rest in bed in all trials. Two trials were assessed to have low risk of bias and two to have moderate to high risk of bias. The results were heterogeneous. Results from one high quality trial of patients with acute simple LBP found small differences in functional status [Weighted Mean Difference (on a 0-100 scale) 6.0 (95% CI: 1.5, 10.5)] and length of sick leave [WMD 3.4 days (95% CI: 1.6, 5.2)] in favour of staying active compared to advice to stay in bed for two days. The other high quality trial compared advice to stay active with advice to rest in bed for 14 days for patients with sciatic syndrome, and found no differences between the groups. One of the high quality trials also compared advice to stay active with exercises for patients with acute simple LBP, and found improvement in functional status and reduction in sick leave in favour of advice to stay active. REVIEWER'S CONCLUSIONS: The best available evidence suggests that advice to stay active alone has small beneficial effects for patients with acute simple low back pain, and little or no effect for patients with sciatica. There is no evidence that advice to stay active is harmful for either acute low back pain or sciatica. If there is no major difference between advice to stay active and advice to rest in bed, and there is potential harmful effects of prolonged bed rest, then it is reasonable to advise people with acute low back pain and sciatica to stay active. These conclusions are based on single trials.

Bed Rest↗
PubMed1994

Electromyography of back muscles during quadrupedal and bipedal walking in primates.

Despite the extensive electromyographic research that has addressed limb muscle function during primate quadrupedalism, the role of the back muscles in this locomotor behavior has remained undocumented. We report here the results of an electromyographic (EMG) analysis of three intrinsic back muscles (multifidus, longissimus, and iliocostalis) in the baboon (Papio anubis), chimpanzee (Pan troglodytes), and orangutan (Pongo pygmaeus) during quadrupedal walking. The recruitment patterns of these three back muscles are compared to those reported for the same muscles during nonprimate quadrupedalism. In addition, the function of the back muscles during quadrupedalism and bipedalism in the two hominoids is compared. Results indicate that the back muscles restrict trunk movements during quadrupedalism by contracting with the touchdown of one or both feet, with more consistent activity associated with touchdown of the contralateral foot. Moreover, despite reported differences in their gait preferences and forelimb muscle EMG patterns, primates and nonprimate mammals recruit their back muscles in an essentially similar fashion during quadrupedal walking. These quadrupedal EMG patterns also resemble those reported for chimpanzees, gibbons and humans (but not orangutans) walking bipedally. The fundamental similarity in back muscle function across species and locomotor behaviors is consistent with other data pointing to conservatism in the evolution of the neural control of tetrapod limb movement, but does not preclude the suggestion (based on forelimb muscle EMG and spinal lesion studies) that some aspects of primate neural circuitry are unique.

Animals↗
PubMed1990

Back pain following general anaesthesia and surgery: evaluation of risk factors and the effect of an inflatable lumbar support.

Factors that contribute to postoperative lumbar back pain and the effect of an inflatable lumbar support on the incidence of postoperative backache were examined. The study consisted of two parts, a pilot study in which mathematical models for appropriate support pressures were produced and the main study to assess the role of an inflatable lumbar support. The use of a support reduced the incidence of back pain on the first postoperative day from 46 to 21 per cent (P = 0.007). The patient's sex, height, weight, and the presence or absence of obesity were not found to be significant factors in the incidence of postoperative back pain. Previous back pain or arthritis in any joint tended to be associated with an increase in the severity and incidence of postoperative back pain. Postoperative back pain was more severe after procedures lasting more than 40 min. Early mobilization reduced the amount of back pain. In conclusion, patients benefit from the use of an inflatable lumbar support if they have previously suffered from backache or if they are to be anaesthetized for more than 40 min.

Adult↗
PubMed1992

Contribution of vertebral deformities to chronic back pain and disability. The Study of Osteoporotic Fractures Research Group.

Among 2992 white women aged 65-70 years recruited from population-based listings, we measured radiographic vertebral dimensions of T5-L4 and calculated ratios of heights: anterior/posterior, mid/posterior, and posterior/posterior of either adjacent vertebra. The degree of deformity for each vertebra was analyzed in terms of the number of standard deviations (SD) that ratio differed from the mean ratio calculated for the same vertebral level in this population. We correlated the severity of each woman's worst vertebral deformity with back pain, back disability in six activities of daily living, and height loss since age 25. Only 39.4% of the cohort had no vertebral deformity; 10.2% had a deformity greater than or equal to 4 SD. Vertebral deformities less than 4 SD below the mean were not associated with increased back pain, disability, or loss of height. In contrast, women whose deformity was greater than or equal to 4 SD had a 1.9 (95% CI, 1.5-2.4) times higher risk of moderate to severe back pain and a 2.6 (95% CI, 1.7-3.9) times higher risk of disability involving the back; they were also 2.5 (95% CI, 2.0-3.2) times more likely to have lost greater than or equal to 4 cm in height. All three types of vertebral deformity (wedge, end plate, and crush) were equally associated with these outcomes. Multiple deformities less than 4 SD did not increase the likelihood of these three outcomes, but multiple deformities greater than or equal to 4 SD tended to be associated with increased back pain, disability, and height loss. This large cross-sectional study suggests that vertebral deformities cause substantial pain, disability, or loss of height only if vertebral height ratios fall 4 SD below the normal mean. Much back pain could not be attributed to vertebral deformities, suggesting other causes.

Aged↗
PubMed1999

Back pain in women post-partum is not a unitary concept.

BACKGROUND AND PURPOSE: At least half of all pregnant women experience back pain at some time during pregnancy and some of them also have persisting back pain post-partum. The aim of the present study was to identify and classify back problems in women post-partum by use of different pain provocation tests and define their relationship to spinal sagittal configuration and mobility. METHOD: One hundred and nineteen women with back pain persisting two months after delivery were interviewed and examined, on average 7.2 months post-partum. Ten clinical pain provocation tests were performed. The first was performed to identify hip pain, the second to identify radiating pain and the other eight tests were performed to provoke pain in the areas of the posterior pelvic/sacroiliac joints, the symphysis pubis and the lumbar spine. The spinal sagittal configuration and mobility were measured in the thoracic and lumbar spine, respectively, with Debrunner's kyphometer (Protek AG, Berne, Switzerland). RESULTS: Twenty-seven per cent of women had pain in the area of the posterior pelvic/sacroiliac joints, 18% in the area of the lumbar spine, 39% both in the area of the posterior pelvic/sacroiliac joints and in the lumbar spine, and in 16% no pain could be provoked. There were no statistically significant differences between the four groups with respect to the spinal sagittal configuration or the mobility in the thoracic or lumbar spine. CONCLUSIONS: Back pain post-partum is not a unitary concept. Based on the clinical tests, women with back pain post-partum can be separated into groups with different pain localizations. The measuring of the spinal sagittal configuration and mobility did not help to further identify or classify post-partum back pain.

Adult↗
PubMed2001

Vertical anthropometric measures and low back pain in adolescents.

BACKGROUND AND PURPOSE: The present paper explores aspects of a large dataset of adolescent potentiates of low back pain. Standing, trunk and shoulder height, subischial height, weight and mean leg length are examined in relation to reports of low back pain in the last two weeks, in strata of age and gender. METHOD: The present study examined 1254 adolescents, aged 11-18 years, drawn from 12 Adelaide public high schools during 1998. RESULTS: At each year of age, girls reported significantly more low back pain than boys. Girls and boys at each year of age provided different relationships between low back pain and anthropometric features, highlighting the unique nature of adolescent growth. The most consistent findings were anthropometric differences between 16-year-old boys, and 13- and 15-year-old girls, with and without low back pain, who may be at critical stages of the peak growth curve. CONCLUSION: We suggest a high prevalence of low back pain in adolescents, and that young sufferers with low back pain may be reflecting attributes of their stage of anthropometric growth.

Adolescent↗
PubMed2004

Attitudes and beliefs of Brazilian and Australian physiotherapy students towards chronic back pain: a cross-cultural comparison.

BACKGROUND AND PURPOSE: The attitudes and beliefs of physiotherapists and students can potentially influence the outcome of treatment of low back pain. These attitudes and beliefs may be influenced by external factors, such as ethnicity. No study that compared the attitudes and beliefs of physiotherapy students from different cultural backgrounds, such as from Brazil or Australia, towards chronic low back pain was found. The purpose of the present study was therefore to compare the attitudes and beliefs of Brazilian physiotherapy students with those of Australian physiotherapy students and to published data from North American healthcare providers, and to investigate whether a history of chronic low back pain affects students' attitudes and beliefs. METHOD: A survey study design was used. Data were collected from 153 Brazilian physiotherapy students and compared with existing data from Australian physiotherapy students who had never been exposed to a chronic low back pain teaching module. Students' attitudes and beliefs were assessed by use of the HC-PAIRS questionnaire. These data were also compared with published data from North American healthcare providers. RESULTS: The Brazilian physiotherapy students had significantly higher scores on the HC-PAIRS questionnaire than the Australian students and the North American healthcare providers. A previous history of chronic low back pain did not affect students' attitudes and beliefs. CONCLUSIONS: As demonstrated by higher HC-PAIR scores, the Brazilian physiotherapy students agree more strongly with the notion that low back pain justifies disability and activity limitation than do Australian physiotherapy students and North American healthcare providers. A history of chronic low back pain does not affect students' attitudes and beliefs.

Adult↗
PubMed1988

Benefits of a back care and light duty health promotion program in a hospital setting.

Back injuries are a common and expensive problem in industry in terms of both direct and indirect costs. A dramatic increase in the costs of workers' compensation for work-related back injuries occurred from 1981-1985 in a hospital setting. During this five-year period, costs of back injuries rose from $36,384 to $272,751, a 750% increase, and the incidence per thousand employees rose from 21 in 1981 to 33 in 1985. A back care education program was instituted by the Physical Therapy Department and Employee Health Service for all departments within the hospital, with content tailored to individual job requirements. Because employees who have had one back injury are at risk for reinjury, an "at risk" program was also developed. For those injured employees without time off work and without need for medical care, a private session with a physical therapist is required to assess musculoskeletal problems and to review posture and body mechanics directly related to specific job tasks. Those employees unable to work in their usual positions are assigned to temporary modified jobs as part of the Light Duty Program. In 1986, following the institution of these two programs in the hospital, the cost of back injuries dramatically decreased to $72,296, a $200,000 drop, and the incidence per thousand employees fell to fifteen. The efficacy of this health promotion intervention program was confirmed both in the cost benefit to the hospital as well as in reduction in incidence of low back injury.

Back Pain↗
PubMed2005

[Attendance at back care programmes: a representative study of the working population in Germany].

OBJECTIVES: To investigate nationwide participation rates in back care programmes of the German working population. METHODS: From a national health survey conducted in Germany between October 1997 to March 1999 (n = 3313 employees aged 18 to 69), we investigated how participation in back care programmes correlates with sociodemographic characteristics, occupation, lifestyle and health factors. RESULTS: Approximately one out of six (17.5%) employee has ever attended a back care class. 7.2% took part in this kind of health promotion programme during the past year. After adjusting for various symptom prevalences, the survey revealed that males, full-time employees, singles and people with an unfavourable lifestyle were less likely to attend such programmes. CONCLUSIONS: This paper is the first to provide representative data on uptake of back care classes and investigate the correlates of participation in back care programs in Germany. The study indicates that people with the highest risk for low back pain are the least likely to take back care classes.

Adolescent↗
PubMed2005

Vertebral deformity, back symptoms, and functional limitations among older women: the Framingham Study.

Vertebral deformity is the most common manifestation of osteoporosis. The purpose of this study was to determine the relation between incident vertebral deformity and back symptoms; and limitations in nine specific functional activities. Subjects were participants in the Framingham Study, a longitudinal, population-based sample involving residents of Framingham, MA, USA. Subjects consisted of 444 surviving female members of the original cohort who had baseline (1968-1975) and follow-up (1992-1993) spine radiographs evaluated for deformity using a semiquantitative scale. Ages ranged from 72 to 96 years. At the follow-up examination, subjects were asked if they experienced pain, aching, or stiffness in their back on most days and if they had difficulty performing nine specific functional skills. We found that incident vertebral deformity was associated with limitations in several functional activities, most notably, pushing or pulling a large object (OR 2.51, 95% confidence interval 1.40, 4.52). For most activities, there was no increase in the risk of functional limitations among women with vertebral deformity who did not report back symptoms at the end of the follow-up compared with those without vertebral deformity or back symptoms. For several functional activities, individuals with both vertebral deformity and back symptoms had greater limitations than would be expected from the additive contribution of both conditions. Back symptoms were associated with limitations in most functional activities, even in the absence of vertebral deformity. Efforts to prevent and treat back pain, independent of vertebral deformity status, might help to reduce functional limitations in older women.

Activities of Daily Living↗
PubMed2006

Reduction in the risk of developing back pain persists at least 30 months after discontinuation of teriparatide treatment: a meta-analysis.

INTRODUCTION: Teriparatide [rhPTH (1-34)] reduces fracture risk, and in a published meta-analysis of clinical trials, teriparatide-treated patients had reduced incidence of back pain relative to placebo or to antiresorptive drugs. The aim of this study was to evaluate back pain in teriparatide-treated versus comparator-treated patients during an interval including controlled clinical trials plus 30 months of additional follow-up. METHODS: A meta-analysis of four completed randomized, double-blinded trials of teriparatide [rhPTH (1-34)] versus comparator was performed. A multivariate Cox proportional hazards model was used to assess the heterogeneity of results and to estimate the relative risk of back pain. RESULTS: Patients in the pooled teriparatide group had reduced risk for any back pain [relative risk, 0.73 (95% CI, 0.61-0.87)], moderate or severe back pain [0.72 (0.58-0.89)], and severe back pain [0.39 (0.25-0.61)] compared with pooled controls, from initiation of the study drug through the end of follow-up. Sensitivity analysis showed that the results were robust to the removal of each individual trial from the meta-analysis. Separate meta-analyses comparing teriparatide versus placebo or antiresorptive drugs gave similar results. CONCLUSIONS: Teriparatide-treated patients had a reduced incidence of back pain versus those receiving a comparator during an observation encompassing clinical trials plus 30 months of posttreatment observation.

Back Pain↗
PubMed2005

Cardiopulmonary resuscitation and back injury in ambulance officers.

OBJECTIVE: Cardiopulmonary resuscitation (CPR) is frequently performed by allied health professionals, and, if undertaken in compromised positions, it may induce injury to the rescuer's spine. Back pain as an occupational symptom in manual workers 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 that explored the difficulties encountered by ambulance officers during the CPR procedure. METHODS: A questionnaire was sent to ambulance officers who had CPR experience through the Director and station officers-in-charge of the Fire Services Department in Hong Kong. RESULTS: Analysis of 318 completed questionnaires showed that the duration of the CPR procedure could last up to 32 min. Two hundred and ninety ambulance officers had experience in delivering CPR on a bed, and 60% of them often had to climb onto the bed with their legs overhanging to perform CPR. Eighty-nine percent were often required to turn their head or twist their back to look at the monitor during CPR. Almost 60% complained of always, and 36% sometimes, experiencing back discomfort during CPR. Only 4.5% had no experience of back discomfort during CPR. Seventy-six (24%) respondents suffered back injury, and as many as 62% of these 76 officers considered the cause of their back injury was related to CPR delivery. Nearly 50% of respondents reported that it was difficult to maintain balance and concurrently deliver CPR while travelling in the ambulance or when the patient was being transported from one location to another. CONCLUSIONS: Results of this survey suggest that there is a need to review the support given to ambulance officers to ensure safe administration of CPR, particularly during ambulance transport.

Ambulances↗
PubMed2004

Comparison of a high-intensity and a low-intensity lumbar extensor training program as minimal intervention treatment in low back pain: a randomized trial.

In a randomized, observer-blinded trial, the effectiveness of 3-month high-intensity training (HIT) of the isolated lumbar extensors was compared to low-intensity training (LIT). Eighty-one workers with nonspecific low back pain longer than 12 weeks were randomly assigned to either of the two training programs. Training sessions were performed on a modified training device that isolated the lower back extensors. Total intervention time was limited to 5-10 min (one or two training sessions) per week. Training effects were assessed in terms of changes in self-rated degree of back complaints, functional disability, and general, physical and mental health. Secondary outcomes in this study were muscle strength and fear of moving the back (kinesiophobia). Outcomes were evaluated at 1,2, 3, 6, and 9 months after randomization. The results showed that the two treatment programs led to comparable improvements in all outcome measures, except for mean isometric strength at 1, 2, 3, 6, and 9 months and kinesiophobia score at 2 and 9 months of follow-up. The high-intensity training group showed a higher strength gain (24 to 48 Nm) but a smaller decline in kinesiophobia (2.5 and 3.4 points, respectively), compared to the low-intensity training group. It can be concluded that high-intensity training of the isolated back extensors was not superior to a non-progressive, low-intensity variant in restoring back function in nonspecific (chronic) low back pain. In further research, emphasis should be put on identifying subgroups of patients that will have the highest success rate with either of these training approaches.

Adult↗
PubMed2004

Low back pain prevention's effects in schoolchildren. What is the evidence?

Given the high prevalence rates of back pain, as early as in childhood, there has been a call for early preventive interventions. To determine which interventions are used to prevent back problems in schoolchildren, as well as what the evidence is for their utility, the literature was searched to locate all investigations that used subjects under the age of 18 and not seeking treatment. Included investigations were specifically designed as an intervention for low back pain (LBP) prevention. Additionally, a literature search was performed for modifiable risk factors for LBP in schoolchildren. The literature-update search was performed within the scope of the "COST Action B13" of the European Commission, approved for the development of European guidelines for the management of LBP. It was concluded that intervention studies in schoolchildren focusing on back-pain prevention are promising but too limited to formulate evidence-based guidelines. On the other hand, since the literature shows that back-pain reports about schoolchildren are mainly associated with psychosocial factors, the scope for LBP prevention in schoolchildren may be limited. However, schoolchildren are receptive to back-care-related knowledge and postural habits, which may play a preventive role for back pain in adulthood. Further studies with a follow-up into adulthood are needed to evaluate the long-term effect of early interventions and the possible detrimental effect of spinal loading at young age.

Adolescent↗
PubMed1989

Is recurrent low back trouble associated with increased lumbar sagittal mobility?

The hypothesis that increased lumbar sagittal mobility constitutes a risk factor for recurrent low back trouble was tested in respect of two specific groups of subjects thought likely to display this phenomenon: young females reporting recurrent back pain, and middle-aged adults reporting recurrent or persistent sciatic symptoms. Lumbar flexibility was estimated from back surface curvatures by a validated technique which uses a flexicurve to record mobility in upper (T12-L4) and lower (L4-S2) lumbar regions. Mean mobility for young females (less than 40 years) with recurrent back pain was less, though not significantly so, than those without back trouble. A loss of mobility was also found in young males with recurrent trouble. However, it was a proportionally greater loss than that found in the females and was statistically significant. The mean mobility for middle-age adults with recurrent sciatic symptoms was significantly reduced compared to those without a history of back trouble. Whilst these results failed to support the general hypothesis, it remains possible that aspects of increased mobility not studied here, such as localized segmental instability or abnormal coupled motions, may be associated with an increased frequency of recurrent low back trouble.

Adolescent↗
PubMed1991

Electromyographic recordings of low back pain subjects and non-pain controls in six different positions: effect of pain levels.

Surface electromyographic (EMG) activity recordings of bilateral paraspinal muscle tension were measured twice on 20 non-pain controls and on 46 low back pain subjects (21 individuals with intervertebral disk disorders and 25 subjects with unspecified musculoskeletal backache) during 6 positions: standing, bending from the waist, rising, sitting with back unsupported, sitting with back supported, and prone. Back pain subjects were measured during both low pain and high pain states. Results revealed a non-significant trend for all subjects, regardless of diagnosis, to have higher paraspinal muscle tension levels on the second (or high pain) assessment. A significant diagnosis by position interaction was observed which was similar to the interaction in our previous study which employed only a single measurement session. Analysis of simple main effects revealed this to be due to control subjects during the standing position having lower EMG levels than the back pain groups, and intervertebral disk disorder subjects having higher EMG levels than the other groups during the supported sitting position. As in our previous study, diagnosis was found to be a clinically significant factor, in that controls had much fewer clinically abnormal readings than back pain patients. The lack of a significant effect for pain state is congruent with findings in the headache literature. The importance of clearly defined diagnostic categories in low back pain research and the utility of measuring subjects in various positions is discussed, as are possible explanations for lack of significant pain state findings.

Adolescent↗