Prior History Of Low Back Pain Research Articles

Role of the Flexion Relaxation Phenomenon in the Analysis of Low Back Pain Risk in the Powerlifter: A Proof-of-Principle Study.

Unlike the most common training approaches for bodybuilding, powerlifting programs are generally based on maximum and submaximal loads, putting enormous stresses on the lumbar spine. The flexion relaxation phenomenon evaluation is a clinical tool used for low back pain (LBP) assessment. This study aimed to evaluate the role of the flexion relaxation phenomenon in the analysis of LBP in the powerlifters. Healthy professional powerlifters participated in the study. In fact, we divided the participants into a LBP-low-risk group and a LBP-high-risk group, based on a prior history of LBP. Outcome measures included flexion relaxation ratio (FRR) and trough surface electromyography collected during trunk maximum voluntary flexion; furthermore, during a bench press lifting, we measured the height of the arched back(ARCH), using a camera and the Kinovea video editing software, to consider a potential correlation with the risk of LBP. We included a group of 18 male (aged 24-39y) powerlifters of 93kg category. We measured a nonsignificant mean difference of ARCH between low-risk LBP group and high-risk LBP subjects. Curiously, maximum voluntary flexions were both above the threshold of 3.2μV; therefore, with an absence of appropriate myoelectric silence, on the contrary, the FRR ratios were higher than 9.5, considering the presence of the phenomenon, exclusively for the low-risk group. The lumbar arched back measurement data did not report any association with the LBP risk, regarding the maximum voluntary flexion value, and even more than the FRR there is a relationship with the presence or the absence of LBP risk. FRR could be considered as a useful parameter for studying the risk of LBP in powerlifting. The FRR index not only refers to the possible myoelectric silence of the lumbar muscles in trunk maximum forward flexion but also takes into account the energy value delivered by the lumbar muscles during the flexion. Furthermore, we can indicate that the size of the powerlifter ARCH may not be a determining factor in the occurrence of LBP.

Occupational Characteristics of Low Back Pain Among Standing Workers in a Japanese Manufacturing Company.

Low back pain (LBP) is a major public health problem that adversely affects the quality of life (QOL) of workers. The etiology of LBP is considered to be multi-factorial with individual, physical, and psychosocial factors contributing to its development and persistence. Although prevention of LBP in workers in the workplace is very important, only a small number of studies have assessed the risk factors and epidemiology of LBP among Japanese factory workers who stand as part of their job. This cross-sectional study investigated the prevalence of LBP in 691 factory employees who conducted their work while standing. Health-related QOL was evaluated using the Roland-Morris Disability Questionnaire (RDQ) to quantify the severity of LBP with the aim of identifying risk factors for LBP among workers who stand as part of their work in an electronics manufacturing company. We observed that the prevalence of LBP lasting for at least 48 hours within a week was 20.0% among participants, with female employees and those with a prior history of LBP having a significantly increased risk of developing LBP. The distribution of the RDQ score showed a negative regression curve among the employees, which was different from the normal distribution pattern reported previously in Japanese patients with LBP. These findings suggest that prolonged standing among factory workers poses an increased risk for LBP.

The greatest risk for low-back pain among newly educated female health care workers; body weight or physical work load?

BackgroundLow back pain (LBP) represents a major socioeconomic burden for the Western societies. Both life-style and work-related factors may cause low back pain. Prospective cohort studies assessing risk factors among individuals without prior history of low back pain are lacking. This aim of this study was to determine risk factors for developing low back pain (LBP) among health care workers.MethodsProspective cohort study with 2,235 newly educated female health care workers without prior history of LBP. Risk factors and incidence of LBP were assessed at one and two years after graduation.ResultsMultinomial logistic regression analyses adjusted for age, smoking, and psychosocial factors showed that workers with high physical work load had higher risk for developing LBP than workers with low physical work load (OR 1.8; 95% CI 1.1–2.8). In contrast, workers with high BMI were not at a higher risk for developing LBP than workers with a normal BMI.ConclusionPreventive initiatives for LBP among health care workers ought to focus on reducing high physical work loads rather than lowering excessive body weight.

Multifidus size and symmetry among chronic LBP and healthy asymptomatic subjects

Previous studies have provided evidence of multifidus muscle atrophy in people with low back pain (LBP). In cases of acute LBP, these studies have shown that the pattern of atrophy is both vertebral level and side specific. For chronic LBP, there are conflicting reports about the extent and location of muscle atrophy. The purpose of this study was to compare chronic LBP patients and asymptomatic subjects on measures of multifidus size (cross-sectional area; CSA) and symmetry (proportional difference of relatively larger side to smaller side). Data were obtained from 40 asymptomatic subjects without a prior history of LBP (13 females, 27 males), and a retrospective audit was undertaken of records from 50 chronic low back pain patients (27 females, 23 males) presenting to a back pain clinic. Results of the analysis showed that chronic LBP patients had significantly smaller multifidus CSAs than asymptomatic subjects at the lowest two vertebral levels. Males were found to have significantly larger multifidus CSAs than females at all vertebral levels except L5, the most common symptomatic level as determined by manual examination. The greatest asymmetry between sides was seen at the L5 vertebral level in patients with unilateral pain presentations. The smaller multifidus CSA was ipsilateral to the reported side of pain in all cases. The results of this study support previous findings that the pattern of multifidus muscle atrophy in chronic LBP patients is localized rather than generalized. Furthermore, between side asymmetry may be seen in chronic LBP patients presenting with a unilateral pain distribution.

Clinical Examination Variables Discriminate Among Treatment-Based Classification Groups: A Study of Construct Validity in Patients With Acute Low Back Pain

Treatment-based classification (TBC) provides matched interventions for patients with acute low back pain (LBP) through key history and clinical findings. This study investigated the discriminant validity of TBC by determining whether commonly used clinical examination variables discriminated among TBC groups. The mean age of the 131 participants was 37.7 years (SD=10.1), 66 participants (50.4%) were female, mean duration of LBP was 16.5 days (SD=16.1), and 60 participants (45.8%) had a prior history of LBP. Fifty-one study participants (38.9%) were classified for specific exercise, 42 (32.1%) for mobilization, 28 (21.4%) for immobilization, and 10 (7.6%) for traction. One-way analyses of variance and Kruskal-Wallis tests were used to investigate differences in clinical variables by TBC group. Then, discriminant function analysis (DFA) predicted TBC group membership. The TBC groups differed on present pain intensity, duration of LBP, and history of LBP. Present pain intensity, duration of LBP, total lumbar flexion, presence of leg pain, and history of LBP produced 2 statistically significant discriminant functions that predicted TBC group membership. These functions correctly classified (cross-validation value in parentheses) 65% (65%) for specific exercise, 45% (40%) for mobilization, and 32% (32%) for immobilization. This study provided evidence supporting the discriminant validity of TBC. Additional diagnostic information related to TBC groups was generated.

Low back pain: what is the long-term course? A review of studies of general patient populations.

It is often claimed that up to 90% of low back pain (LBP) episodes resolve spontaneously within 1 month. However, the literature in this area is confusing due to considerable variations regarding the exact definitions of LBP as well as recovery. Therefore, the claim--attractive as it might be to some--may not reflect reality. In order to investigate the long-term course of incident and prevalent cases of LBP, a systematic and critical literature review was undertaken. A comprehensive search of the topic was carried out utilizing both Medline and EMBASE databases. The Cochrane Library and the Danish Article Base were also screened. Journal articles following the course of LBP without any known intervention were included, regardless of study type. However, the population had to be representative of the general patient population and a follow-up of at least 12 months was a requirement. Data were extracted independently by two reviewers using a standard check list. The included articles were also independently assessed for quality by the same two reviewers before they were studied in relation to the course of LBP using various definitions of recovery. Thirty-six articles were included. The results of the review showed that the reported proportion of patients who still experienced pain after 12 months was 62% on average (range 42-75%), the percentage of patients sick-listed 6 months after inclusion into the study was 16% (range 3-40%), the percentage who experienced relapses of pain was 60% (range 44-78%), and the percentage who had relapses of work absence was 33% (range 26-37%). The mean reported prevalence of LBP in cases with previous episodes was 56% (range 14-93%), which compared with 22% (range 7-39%) for those without a prior history of LBP. The risk of LBP was consistently about twice as high for those with a history of LBP. The results of the review show that, despite the methodological variations and the lack of comparable definitions, the overall picture is that LBP does not resolve itself when ignored. Future research should include subgroup analyses and strive for a consensus regarding the precise definitions of LBP.

1988 Volvo award in clinical sciences. Facet joint injection in low-back pain. A prospective statistical study.

From January 1980 through December 1984, 454 patients were evaluated with facet joint injections. All had the chief complaint of low-back pain, normal neurologic examinations and no root tension signs. Three hundred and ninety completed the protocol, which included a lumbar motion pain assessment before and after facet injection. A total of 127 variables were studied. There were 229 males and 161 females with a median age of 38. Facet joint arthrograms were performed prior to intra-articular injection of local anesthetic and cortisone. Initial mean pain relief was only 29%. Variables correlating significantly (P less than 0.05) with more postinjection pain relief were older age, prior history of low-back pain, normal gait, maximum pain on extension following forward flexion in the standing position, and the absence of leg pain, muscle spasm and aggravation of pain on Valsalva. Greatest pain relief immediately after injection was seen with lumbar extension and rotation, motions reported to stress the facet joints or aggravate pain of facet joint origin. Patients with more pain on lumbar extension and rotation as a group, however, did not get more pain relief. From this study we were not able to identify clinical facet joint syndromes or predict patients responding better to this procedure. The facet joints were not commonly the single or primary source for low-back pain in the great majority (greater than 90%) of patients studied.