From: Scand J Public Health. 2012 Feb 3. [Epub ahead of print]

To study whether having ever had local low back pain, sciatica, neck pain, or some combination of low back pain and neck pain, predicts sickness absence among municipal employees. The study sample (n=6911, 80% women, response rate 67%) included employees of the City of Helsinki who reached the age of 40, 45, 50, 55, or 60 years between 2000-02. Survey data on pain, working conditions, and health behaviours were linked to register data on sickness absence for three subsequent years. Sickness absence was categorised as self-certified (lasting for 1-3 days) and medically certified (lasting for 4 days or more) and the number of spells during the follow up was analysed using Poisson regression analysis.

In women, medically certified sickness absence was predicted by sciatica, neck pain and the combination of sciatica and neck pain, allowing for working conditions, body mass index, and smoking. Local low back pain did not predict medically certified sickness absence. Self-certified sickness absence was modestly predicted by all pain categories and by neck pain alone and with local low back pain or sciatica in men.

Medically certified sickness absence was predicted by sciatica and neck pain, but not by local low back pain. The association was accentuated in those with both sciatica and neck pain. Pain combinations may have a stronger effect on work ability than pain in one location.

From: BMC Musculoskelet Disord. 2012 Jan 24;13(1):7.

Nearly 4 million people in Australia suffer from back pain at any one time, with total treatment costs exceeding $1 billion a year. In the US, the figure is an astonishing US$32 billion a year. Back complaints are the seventh most common condition in patients consulting general practitioners in Australia, and the most common musculoskeletal condition. It is also the most common health problem for which an imaging test is ordered by a general practitioner.

A potential solution to managing the problem of low back pain is the identification and control of modifiable risk factors. This approach is appealing and seemingly logical and there are notable examples where such an approach has provided major improvements in public health. For back pain this approach has not yet been fruitful: Cochrane reviews of workplace interventions, insoles and lumbar supports have failed to support these traditional back pain prevention approaches. Prevention strategies have to date been largely based on controlling long-term exposure to risk factors, for example, modifying seats to control vibration in truck drivers. However it is likely that the full potential of prevention will not be reached unless we also consider commonly occurring, modifiable risk factors that happen just before the onset of back pain. In this regard the authors see this proposed research as complementary to, rather than in conflict with, research evaluating long term risk factors.

The existence of short term risk factors or ‘triggers’ is consistent with the time course of back pain. It is well established that most people will experience low back pain in their lifetime, that pain is typically recurrent and that episodes are usually of sudden onset. For example research conducted by this group demonstrated that in an inception cohort of 969 subjects, 82% reported that their onset of low back pain was sudden. This pattern of low back pain suggests that rather than solely looking at long term exposure to risk factors it would be instructive to also look closely at events occurring immediately prior to the episode to identify modifiable triggers to the episode. This information is routinely sought by health practitioners when a patient with low back pain seeks care. The treating clinician commonly asks the patient what activity they were performing just prior to the onset of pain, in essence, “was the episode triggered by something unusual that happened just before?” The scientific method best suited to answer this question is the case-crossover design.

The authors will use the case-crossover design to provide the first accurate estimates of the transient increase in risk of low back pain associated with transient exposure to various triggers. It is possible that they will identify several factors that are not modifiable but this information will be extremely important to our understanding and explanation of the causes of low back pain.

From: Man Ther. 2012 Jan 17. [Epub ahead of print]

Low back pain may be related to patterns of lumbar postures and movements used to perform different tasks, but it is unclear which patterns with which tasks contribute to low back pain. For example, increases in both lumbar flexion and extension have been linked to low back pain. Some studies have reported increased lumbar flexion in people with low back pain during activities involving flexion, such as golfing and cycling. Other studies have reported that increased lumbar extension is associated with low back pain during sitting. Inconsistent findings regarding the direction of increased lumbar movement or the presence of flexed versus extended postural alignment potentially associated with low back pain may be due to the inclusion of subjects with widely varying movement patterns in a single low back pain group. Several researchers have proposed that there are subgroups of people with low back pain whose symptoms are associated with different direction related postures or movement patterns (e.g., flexion or extension related).

If multiple low back pain subgroups are studied as a single population, differences between subgroups demonstrating patterns in opposite directions could average out to suggest no difference in motion between people with and without low back pain. When subgrouping was not included in the study design, several studies found no differences in lumbar postural alignment and motion between people with and without low back pain. Still other studies found that decreased lumbar motion is associated with low back pain. Lumbar postural alignment and motion characteristics associated with low back pain may be more clearly identified when people with low back pain are subgrouped based on lumbar patterns associated with symptoms.

Systems of subgrouping people with low back pain have allowed researchers to identify consistent differences in lumbar posture and motion between people with flexion or extension related low back pain symptoms and people without low back pain. Studies that subgrouped people with low back pain using O’Sullivan’s system reported that during typical sitting men with flexion related low back pain sat closer to their end range of available lumbar flexion compared to men without low back pain and that people in a flexion related subgroup sat in more lumbar flexion than people without low back pain and people in an extension related subgroup. Additionally, during slumped sitting, investigators found that people with extension related low back pain demonstrated less end range lumbar flexion than people with flexion related low back pain and people without low back pain. Finally, these investigators also found that people with extension related low back pain demonstrated less end range lumbar flexion during forward bending than people with flexion related low back pain. Investigators using the Movement System Impairment model for low back pain (Sahrmann SA. Diagnosis and treatment of movement impairment syndromes. St. Louis: Mosby, Inc; 2002) found that while there were no differences in standing lumbar alignment between people with and without low back pain, when subgrouped, people with low back pain in an extension related subgroup stood in more lumbar extension than people with low back pain in a flexion related subgroup and people without low back pain. Differences in end range lumbar flexion during flexion related tasks between subgroups based on the Movement System Impairment model have not been studied.

Low back pain may also be related to certain tasks. Some tasks, such as prolonged sitting and frequent forward bending, increase the risk of developing low back pain. However, the growing understanding of subgrouping suggests that the risk of low back pain may be influenced not only by what task is performed, but how high risk tasks are performed. The current study examines end range lumbar flexion during two common high risk tasks: slumped sitting and standing forward bending. End range lumbar flexion, as opposed to total lumbar flexion range of motion, was selected because the authors were only interested in the final position of the lumbar spine. Greater absolute amounts of lumbar flexion, regardless of an individual’s starting position, may indicate greater lumbar tissue laxity and a reduced ability of the passive structures of the lumbar spine to provide stability, particularly in resisting flexion. These tissue characteristics may place people at greater risk for tissue injury and pain. The specific tasks examined in the current study were chosen because they are both common flexion related tasks, but differ in the static versus dynamic nature of the task. The authors assessed the consistency of flexion related patterns across these tasks for two low back pain subgroups classified based on the Movement System Impairment model.

Differences in lumbar posture and motion between low back pain subgroups could be influenced by gender differences. Previous studies of differences in lumbar flexion between low back pain subgroups included more males in flexion related groups and more females in extension related groups. One study comparing people with flexion related low back pain to people without low back pain included only male subjects. The imbalance in gender distributions in past studies may have influenced the subgroup findings. In the back healthy population, it has been reported that men tend to adopt sitting postures and perform movements, such as forward bending, with greater lumbar flexion than women. Additionally, men tend to stand in more lumbar flexion and women in more lumbar extension. These findings suggest that, when there are uneven distributions of males and females, differences in posture and movement patterns between genders could influence differences found between low back pain subgroups. The current research will assess whether subgroup differences are independent of potential gender differences by incorporating comparable distributions of males and females within each subgroup.

The purpose of this study was to examine the effects of low back pain subgroup, classified based on the Movement System Impairment model, on lumbar end range flexion and symptom behaviour with a flexed posture (slumped sitting) and a flexion related movement (forward bending). The study included the two most prevalent of five low back pain subgroups studied to date: rotation and rotation with extension. The rotation subgroup demonstrates patterns of posture and motion and low back pain symptoms during tests associated with lumbar rotation, flexion, and extension. The rotation with extension subgroup demonstrates patterns of posture and motion and low back pain during tests associated with lumbar rotation, and extension, but not flexion. The authors predicted that the rotation subgroup would display greater end range lumbar flexion with slumped sitting and forward bending compared to the rotation with extension subgroup, and that the rotation subgroup would be more likely to report increased symptoms with both tasks than the rotation with extension subgroup. A secondary purpose was to examine differences in end range lumbar flexion between males and females and the effect of such differences on low back pain subgroup results. The authors predicted that males would show greater end range lumbar flexion than females, regardless of low back pain subgroup, and that gender effects would not be specific to either low back pain subgroup.

In this study, two low back pain subgroups, classified according to the Movement System Impairment model, demonstrated predictable differences in end range lumbar flexion across two flexion related tasks. Subjects in the rotation subgroup displayed significantly greater end range lumbar flexion during slumped sitting and a trend towards greater end range lumbar flexion during forward bending than subjects in the rotation with extension subgroup. Despite no differences between subgroups in current pain on the day of testing, the rotation subgroup was also more likely to report increased symptoms with both tasks than the rotation with extension subgroup. During both slumped sitting and forward bending, males displayed greater end range lumbar flexion than females; however, the subgroup differences identified were not the result of gender differences in end range lumbar flexion. Comparable distributions of males and females in each subgroup were used and no interactions between subgroup and gender on end range lumbar flexion were present. These findings support recommendations of subgrouping people with low back pain by demonstrating that subgroups of people with low back pain differ in amounts of end range lumbar flexion during tests of posture and potentially during movement.

The findings of the current study are consistent with previous research on slumped sitting and typical sitting. A prior study demonstrated that during slumped sitting, subjects in a flexion related low back pain subgroup sat in more end range lumbar flexion compared to an extension related low back pain subgroup. Prior studies also demonstrated that during typical sitting, subjects in a flexion related low back pain subgroup sat in more lumbar flexion compared to an extension related low back pain subgroup. The results of the current study are also consistent with others’ observations of end range lumbar flexion during forward bending in people with low back pain. Subjects in a flexion related low back pain subgroup had greater end range lumbar flexion with forward bending compared to subjects in an extension related low back pain subgroup.

The current study also indicates that gender is a factor in end range lumbar flexion during flexion related tasks. The findings are consistent with research on back healthy subjects showing males adopt greater lumbar flexion than females during prolonged sitting and that males have greater lumbar flexion and less hip flexion compared to females during forward bending and a reaching task involving forward bending. In the current study, a similar relationship between lumbar flexion exhibited by men and women during slumped sitting and forward bending was also evident in people with low back pain.

One possible reason for differences in end range lumbar flexion between genders and subgroups could be differences in hip movement. During forward bending, reduced hip flexion might contribute to greater end range lumbar flexion. This could explain differences between males and females observed in this study, where greater lumbar flexion corresponded to reduced hip flexion for males compared to females. It is logical that decreased hamstring flexibility could limit hip flexion motion during forward bending, thereby encouraging greater lumbar flexion to compensate. Studies of healthy individuals have demonstrated that males have reduced hamstring flexibility compared to females. Although there is some evidence to suggest a relationship between reduced hamstring flexibility and decreased pelvic or hip flexion during forward bending in healthy individuals and in people with low back pain, the evidence regarding the relationship between hamstring flexibility and lumbar flexion is equivocal and the studies are limited methodologically. On the other hand, the amount of hip flexion may not influence differences in end range lumbar flexion between subgroups. There were differences in end range lumbar flexion between subgroups, but not in end range hip flexion during forward bending. This may suggest that hip flexibility affecting lumbar motion is not the main issue differentiating subgroups, but rather the issue may be related to the consistent demonstration of lumbar flexion across tasks.

The finding of differences in end range lumbar flexion between genders and subgroups across two different flexion related tasks provides some support to the proposal that people adopt directional, stereotypic patterns of posture and movement. The frequent use of a limited repertoire of stereotypic posture and movement patterns used across many daily activities could lead to microtrauma to lumbar region tissues. It has been proposed that a cycle of spinal ligament subfailure leading to changes in neuromuscular control and subsequent tissue injury plays a role in low back pain. Repeated use of end range flexion across many tasks could potentially result in tissue changes that reduce spinal stability and put people at risk for tissue damage, injury, and pain. For flexion related low back pain subgroups, during postures maintained for long periods of time (e.g., slumped sitting), passive structures could lose their ability to support the spine. During movements that take the lumbar spine into a great amount of lumbar flexion (e.g., forward bending), the combination of stereotypic movement patterns involving exaggerated end range flexion and tissue laxity from prior exposure to flexion postures could promote greater repeated use of certain tissues and further injury to the lumbar spine.

The current study lends support to the proposal that repeated adoption of end range lumbar flexion during many tasks may put people at greater risk for pain during flexion. The rotation subgroup, which showed a pattern of greater lumbar flexion during slumped sitting and forward bending than the rotation with extension subgroup, were more likely to report symptoms during both tests. However, males, who showed greater lumbar flexion during slumped sitting and forward bending than females, were not more likely to report symptoms during either test. Differences in symptoms during both slumped sitting and forward bending found between subgroups, but not between genders, suggest that increased end range flexion values alone do not directly correspond to an increased likelihood of low back pain symptoms. The authors would propose that the interaction of increased end range motion, paired with decreased movement variability across activities and an increased likelihood of performing repeated end range motions, is what sets a person up to develop pain. For the rotation subgroup, avoiding lumbar flexion, particularly end range lumbar flexion, may be an important component of treatment.

The results of this study add further evidence suggesting a link between low back pain and lumbar posture and movement patterns. A greater understanding of the mechanisms that contribute to low back pain development, persistence, and recurrence can provide information to guide preventative and rehabilitative treatments for low back pain. Subgrouping people with low back pain may allow for treatments that target the posture and movement patterns most related to symptoms. Treatments emphasizing modifying lumbar movement patterns based on low back pain subgrouping are showing promise. Additional research on low back pain subgroups can provide further insight into the posture and movement patterns that contribute to low back pain and how this information can be used to improve the care of people with low back pain.

People in the rotation subgroup displayed more end range lumbar flexion during slumped sitting and forward bending than people in the rotation with extension subgroup. Men displayed greater end range lumbar flexion than women during both slumped sitting and forward bending. Differences found between subgroups, however, were not related to gender differences. These results support the proposal that people with low back pain display stereotypic patterns of posture and movement. They also support the need for subgrouping people with low back pain based upon patterns of posture and movement and symptoms consistently displayed across tasks. An increased understanding of differences between subgroups of people with low back pain is necessary to understand what contributes to low back pain problems and to guide preventative and rehabilitative treatment strategies.

Source: Differences in end range lumbar flexion during slumped sitting and forward bending between low back pain subgroups and genders

From: Eur Spine J. 2012 Jan 17. [Epub ahead of print]

This prospective magnetic resonance imaging (MRI) study in chronic low back pain patients evaluated the natural course of degenerative lumbar spine changes in relation to Modic 1 type changes within 1 year. From 3,811 consecutive chronic low back pain patients referred to lumbar spine MRI 54 patients with a large Modic 1 type changes were selected using strict exclusion criteria to exclude specific back disorders. Follow-up MRI was obtained within 11-18 months.

At baseline Modic 1 type changes was associated with an adjacent endplate lesion in 96% of the cases. In follow-up, an unstable Modic 1 type change was associated both with an increase of endplate lesions, decrease of disc height and change in disc signal intensity, most found at L4/5 or L5/S1. In disc spaces without Modic 1 type changes, progression of degenerative changes was rare. Endplate deformation, decreasing disc height and change of disc signal intensity appear essential features of accelerated degenerative process associated with Modic 1 type changes.

From: BMC Musculoskelet Disord. 2011 Sep 13;12:202

The importance of spine stability is a central paradigm in spine care. Maintenance of spine stability, through decreasing excessive or abnormal spinal movement, is the rationale for many commonly used treatments ranging from ‘lumbar stabilization’ rehabilitation to spinal fusion surgery. The spinal degenerative cascade is an important theory related to the concept of spine stability, and was originally popularized by Kirkaldy-Willis. Kirkaldy-Willis described a ‘cascade’ of degenerative changes affecting the three joint complex comprised of the intervertebral disc anteriorly and the lumbar zygapophyseal (‘facet’) joints posteriorly. This degenerative cascade consists of three sequential clinical stages: 1) dysfunction, 2) instability, and 3) stabilization. Kirkaldy-Willis described a mutual interrelationship of the intervertebral disc and facet joints, and pointed out that precipitating events in degeneration could begin not only with the intervertebral disc, but also with the facet joints.

Over time, however, the sequence of spinal degeneration has often been viewed from a more limited standpoint, with the perspective that anterior structure changes affecting the intervertebral disc largely precede- and lead to- posterior structure changes affecting the facet joints. The notion that degeneration begins with the intervertebral disc is described in textbooks of spine care and has been supported by some research studies. Vernon-Roberts conducted a landmark study of fewer than 100 cadaveric specimens that found that degenerative disc changes were always accompanied by facet joint degenerative changes. This study concluded that disc degeneration was the primary event leading to degenerative spondylosis. In an imaging study of 68 subjects with low back pain, Butler et al. also found that facet joint degeneration did not occur in the absence of disc degeneration, but disc degeneration frequently occurred without facet joint degeneration. Butler concluded that discs degenerate before facets. These conclusions were further supported by a recent cross-sectional MRI study of individuals with low back pain. Some authors, however, have questioned the view that disc degeneration necessarily precedes facet degeneration. A prior report notes that facet arthrosis on MRI precedes disc degeneration in 20% of men. Furthermore, in a large study of skeletal specimens (n = 647), Eubanks et al. found that facet joint osteoarthritis often preceded changes of disc degeneration in younger individuals.

Many prior studies of the degenerative cascade that have concluded that disc degeneration uniformly precedes facet degeneration have been based on convenience samples of individuals with low back pain. Given the prevailing notion among clinicians that much low back pain originates from the disc, recruitment from spine clinics therefore presents a probable selection bias in prior samples. No studies have examined a large, community-based sample that is unselected for low back pain. Furthermore, no studies examining the interrelationships between anterior and posterior structure degeneration have used multivariate analyses to adjust for important demographic and anthropometric factors thought to be related to spinal degeneration.

The authors conducted an epidemiologic study of patterns of degeneration in the community-based population of the Framingham Heart Study. The aims of the present study were: 1) to determine the prevalence of different patterns of anterior and posterior spinal structure degeneration in the community-based population, and 2) to examine whether the observed epidemiology is consistent with the view that degeneration always begins with the intervertebral discs, and 3) to determine the independent relationship between anterior structure and posterior structure degeneration, while adjusting for important demographic and anthropometric factors.

The current study is consistent with the view that, for a majority of individuals, degeneration begins with the anterior spinal structures. However, a minority of individuals (10-20%, depending on the definition of anterior degeneration used) across the age spectrum exhibits a pattern of isolated posterior degeneration without substantial loss of disc height, occurring most frequently at the L5-S1 and L4-L5 spinal levels. For these individuals, the factors of age, gender, and BMI may explain, at least in part, the development of posterior structure degeneration without concurrent changes in the disc

Kirkaldy-Willis described spinal degeneration as the result of a complex interaction between the intervertebral discs and facet joints, which begins with precipitating events that could take place in any component of the three-joint complex. He stated clearly, ‘In some patients the changes seen during the course of the progressive degenerative process affect mainly the facet joints’. These findings that some individuals have changes of facet degeneration without any changes of disc height loss is therefore consistent with the Kirkaldy-Willis view, and furthermore is supported by some earlier studies. The seminal cadaveric study by Lewin reported that facet joint osteoarthritis sometimes occurred in the absence of disc degeneration or vertebral osteophytosis. Eubanks’ study of skeletal lumbar spines found that lumbar facet joint osteoarthritis appeared early in the course of aging, often preceding anterior vertebral changes. On the other hand, some cadaveric and imaging studies described above have concluded that disc degeneration always precedes facet degeneration. Taken together, the existing literature suggests that many exceptions exist to the generalization that anterior changes precede posterior changes. These exceptions may be explained by the contributions of increased age, female gender, and higher BMI.

Longitudinal studies in humans are needed to verify whether any of the previously proposed biomechanical, demographic, or anthropometric risk factors for posterior structure degeneration are truly causal. A compelling alternative explanation exists: the predominant influence of heredity in disc degenerative changes has already been shown, and heredity may well explain much of the variation seen in facet degenerative changes as well.

Future longitudinal studies should ideally allow for examination of genetic factors, and should account for other covariates not considered in this study, including occupational loading, prior physical trauma, lumbosacral alignment, and facet joint orientation and tropism. In particular, these findings that isolated posterior degeneration occurred predominantly at the L5-S1 and L4-L5 levels may warrant more detailed consideration of lumbosacral biomechanical factors. Furthermore, since disc height narrowing is a relatively nonspecific finding with poorly understood determinants, future studies should take into account other parameters of disc degeneration, including quantitative assessments of desiccation, herniation, and annular pathology.

The observed epidemiology of lumbar spinal degeneration in the community-based population is consistent with an ordered sequence beginning in the anterior structures, for a majority of individuals. However, some individuals demonstrate atypical patterns of degeneration, beginning in the posterior joints. Increased age and BMI, and female gender, may be related to posterior degeneration in these individuals. Longitudinal studies are needed to better understand the importance of segmental level biomechanics in degeneration, and ideally should include not only these important covariates, but also examination of genetic factors.

Disc desiccation, herniation, annular pathology and genetics are additional variables that affect degeneration and were not factored into the study results.

Source: The source also goes into details regarding the grading methods of anterior and posterior degeneration -Does lumbar spinal degeneration begin with the anterior structures? A study of the observed epidemiology in a community-based population

From: Eur Spine J. 2012 Jan 8. [Epub ahead of print]

Clinical guidelines provide similar recommendations for the management of new neck pain and low back pain but it is unclear if general practitioner’s (GP) care is similar. While GP’s management of low back pain is well documented, little is known about GP’s management of neck pain. We aimed to describe GP’s management of new neck pain and compare this to GP’s management of new low back pain in Australia between April 2000 and March 2010. All GP-patient encounters for a new (i.e. first visit to any medical practitioner) neck pain or low back pain problem were compared in terms of treatment delivered, referral patterns and requests for laboratory and imaging investigations.

General practitioners in Australia have managed new neck pain and low back pain problems at a rate of 3.1 and 5.8 per 1,000 GP-patient encounters, respectively. GP’s primarily utilised medications, in particular non-steroidal anti-inflammatory drugs, to manage new neck and low back pain problems and referred approximately 25% of all patients for imaging. Patients with new neck pain are more frequently managed using physical treatments and were referred more often to allied health professionals and specialists. In comparison, patients with new low back pain were managed more frequently with medication, advice, provision of a sickness certificate and ordering of pathology tests.

This is the first time GP management of a new episode of neck pain has been documented using a nationally representative sample and it is also the first time that the management of back and neck pain has been compared. Despite guidelines endorsing a similar approach for the management of new neck pain and low back pain, in actual clinical practice Australian GPs manage these two conditions differently.

From: Int J Occup Med Environ Health. 2012 Mar;25(1):41-50. Epub 2012 Jan 5

Low back pain is a common health problem among hospital nurses. However, the prevalence, characteristics, and work-related risk factors of low back pain have not been widely investigated in Taiwan.

This study used a cross-sectional survey of 217 hospital nurses to gather self-reported information on the prevalence of back pain, demographic and pain characteristics, and work-related risk factors from 178 respondents who indicated a past history of back pain. The association between the characteristics of back pain and work-related risk factors was also examined.

The lifetime prevalence of back pain was 82.03%, and the point prevalence of back pain was 43.78%. The mean pain score is 41.67. The number of years at work was significantly associated with the pain score for an individual’s most recent episode of back pain, the extent of bothersomeness of back pain and leg pain, and the extent to which back pain interfered with normal work.

Back pain is common among hospital nurses in Taiwan. Years at work are significantly associated with pain severity and disability caused by back pain.

From: Pain. 2012 Jan;153(1):203-10

This study undertook an economic analysis of the costs of early retirement due to back problems, with the aim of quantifying how much lower the value of accumulated wealth of individuals who exit the workforce early due to back problems is by the time they reach the traditional retirement age of 65years – compared to those who remained in the workforce. This was done using the output dataset of the microsimulation model Health&WealthMOD.

It was found that over 99% of individuals who are employed full time will have accumulated some wealth at age 65 years, whereas as little as 74% of those who are out of the labour force due to back problems will have done so. Those who retire from the labour force early due to back problems will have a median value of total accumulated wealth by the time they are 65 of as little as $3708 (for women aged 55-64years). This is far lower than the median value of accumulated wealth for those women aged 55-64 years who remained in the labour force full time, who will have $214,432 of accumulated wealth at age 65 years.

Not only will early retirement due to back problems limit the immediate income available to individuals, but it will also reduce their long-term financial capacity by reducing their wealth accumulation. Maintaining the labour force participation of those with back problems, or preventing the onset of the disease, should be a priority in order to maintain living standards comparable with others who do not suffer from this condition.

From: Ergonomics. 2012 Jan;55(1):87-102

The objective of this study was to measure the effect size of three important factors in manual material handling, namely expertise, lifting height and weight lifted. The effect of expertise was evaluated by contrasting 15 expert and 15 novice handlers, the effect of the weight lifted with a 15-kg box and a 23-kg box and the effect of lifting height with two different box heights: ground level and a 32 cm height. The task consisted of transferring a series of boxes from a conveyor to a hand trolley.

Lifting height and weight lifted had more effect size than expertise on external back loading variables (moments) while expertise had low impact. On the other hand, expertise showed a significant effect of posture variables on the lumbar spine and knees. All three factors are important, but for a reduction of external back loading, the focus should be on the lifting height and weight lifted.

The objective was to measure the effect size of three important factors in a transfer of boxes from a conveyor to a hand trolley. Lifting height and weight lifted had more effect size than expertise on external back loading variables but expertise was a major determinant in back posture.

From: Lijec Vjesn. 2011 Sep-Oct;133(9-10):330-6

Disorders of lumbosacral facet joints are manifested by low back pain with or without referred leg pain and decreased mobility of the lumbosacral spine (lumbosacral facet syndrome). The most frequent causes of lumbosacral facet syndrome are functional disorders (functional blockade or dysfunction of facet joint=reversible restriction of facet joint movements caused by meniscoid entrapment) and degenerative changes of facet joints while the others are less frequent (spondyloarthropathies, infection, tuberculosis, synovial cyst, injury). Although it has been proven that the facet joints are one of the most frequent sources of chronic low back pain (15-45%), the fact is that the facet syndrome has been frequently overlooked in patients with chronic low back pain.

Following are the main reasons for explaining why the facet syndrome has been overlooked in patients with chronic low back pain:

1. Facet joints disorders are manifested by non-specific clinical picture.

2. Diagnosis of facet syndrome cannot be established by either the conventional clinical examination or radiological examinations.

3. A very small number of doctors are practicing manual functional examination which can establish the diagnosis of facet joint dysfunction.

4. Diagnostic anesthetic block which can confirm the facet syndrome diagnosis is not a widely accessible method.

There is a lack of research in frequency of facet syndrome in patients with acute low back pain. Chronic mechanical low back pain caused by dysfunction of several structurally unchanged facet joints can have the same features as the inflammatory pain which can result in misdiagnosis of spondyloarthropathy. Acute lumbosacral facet syndrome caused by dysfunction of facet joints responds very well to manual therapy. The most important therapeutic options in patients with chronic lumbosacral facet syndrome caused by degenerative changes and/or dysfunction of facet joints are manual therapy, kinesiotherapy (flexion exercises), therapeutic blocks and radiofrequency denervation. The article describes etiopathogenesis, clinical manifestations, diagnosis, differential diagnosis and therapy of lumbosacral facet syndrome with emphasis on functional disorders of facet joints that can cause particular diagnostic and therapeutic problems.