History Of Low Back Disorders Research Articles

Physical fitness as a predictor of herniated lumbar disc disease – a 33-year follow-up in the Copenhagen male study

BackgroundThe role of physical fitness (VO2Max (mlO2*min-1*kg-1)) as a risk factor for herniated lumbar disc disease (HLDD) is unknown. The objective of this study was to examine the association between aerobic (physical) fitness and risk of hospitalisation due to HLDD in a long-term follow up.MethodsThe Copenhagen Male Study is a prospective cohort study established in 1970–71. At baseline, 5,249 men answered a questionnaire about their history of back disease, physical and psychosocial working conditions, lifestyle and social class. Height and weight was measured and aerobic capacity (physical fitness) was estimated based on a submaximal bicycle test. Information about hospitalization due to HLDD was obtained from the National Hospital Register covering the period 1977 – 2003. Hazard Ratios (HR) were calculated by Cox’s proportional hazard regression model.ResultsAmong 3,833 men without history of low back disorders, 64 were hospitalized due to HLDD. The cumulative incidence of HLDD was 1.7% (n=34) among men with low physical fitness (15–32 ml O2*min-1*kg-1), and 1.7% (n=30) among men with high physical fitness (33–78 ml O2*min-1*kg-1). In a final model, adjusted for relevant confounders, the HR (95% CI) for HLDD for those with high physical fitness was 0.88 (0.51-1.50) compared to those with low physical fitness. In the same model, HR for men often exposed to strenuous work compared to those seldom or never exposed to strenuous work was 3.91(1.82-8.38). Also body height was a significant predictor.ConclusionsPhysical fitness is not associated with hospitalisation due to HLDD, and the only modifiable risk factor for hospitalisation due to HLDD seems to be strenuousness at work.

Effect of a personal weight transfer device on muscle activities and joint flexions in the stooped posture

Repetitive work in the stooped posture is a known risk factor for developing low back disorders (LBDs); regardless, the stooped posture is widespread throughout the world in the agriculture, construction, and mining industries. An on-body weight transfer device was tested as a possible intervention for reducing the risk of developing LBDs.Eighteen subjects (11 male and 7 female), with no history of LBDs, performed stooped posture tasks in the laboratory. Surface electromyograms of the erector spinae, rectus abdominis, biceps femoris, and tibialis anterior muscles were recorded. Bodily joint flexions were measured with a combination of inclinometers and electrogoniometers.When wearing the device in the stooped posture, biceps femoris activity and lumbar flexion were significantly reduced. Subjects who did not experience flexion–relaxation had a significant reduction in lumbar erector spinae activity.By reducing back muscle activity, and by limiting lumbar flexion, the device could reduce the risk of developing LBDs for those who work while adopting the stooped posture. The device may also be beneficial for those with existing LBDs. Follow up field studies are needed to confirm the long-term potential benefits of such an intervention approach.

Risk factors for the onset of non-specific neck pain: a systematic review

ObjectiveNeck pain is a common musculoskeletal disorder, but little is known about which individuals develop neck pain. This systematic review investigated factors that constitute a risk for the onset of...

들기/내리기 작업 시 소음과 배경음악이 몸통근육 피로도에 미치는 영향

The purpose of this study was to define the effects of noise and background music on the trunk muscle fatigue during dynamic lifting and lowering tasks. Six healthy male subjects with no prior history of low back disorders participated in this study. The participants were exposed to two levels of background noise such as 40dB noise and 90dB noise and three levels of background music such as no music, slow music, and fast music. Six different combinations of background noise and background music were played while the participants were performing the lifting task at 15% level of Maximum Voluntary Contraction. Electromyography signals from six muscles were collected and fatigue levels were analyzed quantitatively. In results, the 90dB noise increased trunk muscle fatigue and slowed down the recovery. The trunk muscle fatigue was the lowest when the fast music was played for as background. After recovery, the 90dB noise increased trunk muscle fatigue. The trunk muscle fatigue was the lowest when the slow music was played for as background. The results can be useful to manage the cumulative fatigue of trunk muscles due to background noise and music during repetitive lifting and lowering tasks in industry.

Spinal shrinkage and recovery in women with and without low back pain

Fowler NE, Rodacki CdeL, Rodacki AL. Spinal shrinkage and recovery in women with and without low back pain. ObjectivesTo assess the behavior of the spinal column after loading in participants with and without low back pain (LBP) using spinal shrinkage measurements as a criterion and to analyze the relations among spinal shrinkage, recovery, and LBP. DesignA case-control study with repeated measures. SettingUniversity department with recruitment from primary care. ParticipantsConvenience sample of 31 women (15 with chronic, nondisabling LBP [LBP group]; 16 with no history of low back disorders [control group]). InterventionsNot applicable. Main outcome measureChanges in body length as determined by using a stadiometer. ResultsThe spinal shrinkage induced by the exercise was similar (P>.05) in both groups (control group, mean ± standard deviation of −3.99±1.13mm; LBP group, −4.16±1.54mm). Differences in spinal length were found after 20 minutes in the recovery position (P<.05). The control group was able to recover stature to a greater extent (111.2%±13.6%) than the LBP group (P<.05), which was unable to regain stature beyond baseline (57.5%±25.1%). A negative correlation was found between regaining stature and low back pain (r=−.52, P<.05). ConclusionsParticipants with LBP were unable to recover stature to the same extent as controls. We suggest that LBP is related to the diminished ability to recover rather than to the magnitude of the spinal shrinkage imposed during the task.

Personal and psychosocial variables in workers with a previous history of LBP: 16-month follow-up

A 16-month longitudinal study was made of workers who perform physically demanding jobs. In a previous study some of these workers were found to have a history of low back disorders sufficient to miss work, and others not. All were asymptomatic at that time. To further quantify the association between various personal and psychosocial parameters that linger due to a history of low back disorders and how they may change after another 16 months of work. Originally, 72 workers were recruited from heavy industry; 26 of whom had a history of disabling low back disorders sufficient to miss work. In the follow-up study, 46 responded all of whom remained at work injury free, 13 belonged to the ‘history of back disorders’ category. While the earlier study suggested that having a history of low back disorders is associated with a larger waist girth, a greater chronicity potential as predicted from psychosocial questionnaires, perturbed flexion to extension strength and endurance ratios, and widespread motor control deficits across a variety of tasks some of which resulted in high back loads, the follow-up showed no difference in reported physical symptoms, or perceived pain over the 16 months. Both groups changed their responses from the original data collection to the 16-month follow-up with the net result of psychosocial distinguishing traits, in those with a history, diminishing. It was concluded that time and work appear to be healing.

Previous history of LBP with work loss is related to lingering deficits in biomechanical, physiological, personal, psychosocial and motor control characteristics

A cross-sectional retrospective study was made of currently asymptomatic workers who perform physically demanding jobs. To further quantify the association between various biomechanical, physiological, personal psychosocial and motor control parameters that linger due to a history of low back disorders. Seventy-two workers were recruited from heavy industry, 26 of whom had a history of disabling low back disorders (LBDs) sufficient to miss work while the others did not. The strength of the study lies in the many detailed variables measured. Having a history of low back disorders was found to be associated with a larger waist girth, a greater potential for low back pain chronicity as predicted from psychosocial questionnaires, perturbed flexion to extension strength and endurance ratios, and widespread motor control deficits across a variety of tasks, some of which resulted in high back loads. In those workers who had missed work due to back disorders, the length of time since their last disabling episode was 261 weeks on average, suggesting that multiple deficits may remain for a period of time. Having a history of LBD is associated with changes in attitudes, in body composition, and in the way people move, load their backs and respond to a variety of motor and stability challenges.

Relationships between lumbar flexibility, sit-and-reach test, and a previous history of low back discomfort in industrial workers.

The sit-and-reach (S&R) test is often included in standard fitness tests (e.g., Canadian Physical Activity, Fitness and Lifestyle Appraisal [CPAFLA]), justified on the assumption that it is an indicator of low back health. Two issues were examined here: Is low back flexibility linked to having a history of low back disorders? And is the S&R test an indicator of low back flexibility? The relationship between S&R test scores, lumbar range of motion, and having a history of low back discomfort was examined in 72 asymptomatic (at test time) industrial workers (70 M, 2 F; mean age 35 ys; height 1.79 m; mass 84.7 kg). The S&R test, among many collected, was performed according to the CPAFLA guidelines. History of low back discomfort (LBD) was categorized based on whether or not time was lost from work. The S&R test was unable to distinguish between those with a history of LBD and those without. Specific lumbar sagittal range of motion could make this distinction. A moderate correlation (r = 0.42) surfaced between S&R and lumbar flexibility. This study suggests that the value of S&R as an indicator of previous back discomfort is questionable and there may be better indicators for inclusion in the CPAFLA.

Stature loss and recovery in pregnant women with and without low back pain

Rodacki CL, Fowler NE, Rodacki AL, Birch K. Stature loss and recovery in pregnant women with and without low back pain. Arch Phys Med Rehabil 2003;84:507-12. Objectives: To assess the loss of stature and its recovery in normal and pregnant women with and without low back pain (LBP) and to examine the relations between spinal shrinkage, recovery, and LBP. Design: Stature changes were measured before and after physical activity in each group and differences in response compared between groups. Setting: A laboratory environment. Participants: Thirty-one women (7 pregnant without LBP, 8 pregnant with LBP, 16 nonpregnant with no history of low back disorders) were recruited using convenience sampling. Controls were recruited from the general community; subjects in the pregnant groups were recruited from local primary care groups. Interventions: Not applicable. Main Outcome Measures: Stature change was assessed as the main outcome measure. Changes in stature were interpreted with respect to the woman[apos]s stature at the start of the trial. Results: Stature loss induced by a moderate physical activity was similar ( P[gt].05) in all groups (control, [minus]3.99[plusmn]1.13mm; pregnant no back pain, [minus]4.23[plusmn]1.23mm; pregnant with back pain, [minus]4.57[plusmn]1.53mm). Differences were found after 20 minutes in a recovery position ( P[lt].05): the controls were able to recover stature to a greater extent (111.2%[plusmn]13.6%) than the other groups ( P[lt].05). A negative correlation was found between regain in stature and LBP in pregnant subjects ( r[equals][minus].81, P[lt].05). Conclusions: The pregnant women with LBP were unable to recover stature to the same extent as the controls and pregnant women without LBP. Results suggest that LBP in pregnancy may be related to the woman[apos]s diminished ability to recover, rather than the magnitude of the spinal shrinkage imposed during the task.

Combination of low back pain and previous low back pain and shoulder stiffness in construction employees.

A postal questionnaire for the prevalence of low back pain was studied with relevance to stiffness of that shoulder and a history of low back disorders in construction employees. The percentage of clerical employees with low back pain was 31.3% and of field workers was 30.3%. Odds ratios representing a relative risk factor for low back pain relating to each age group showed 2.35 in the clerical and 2.10 in the field workers at the age of 30-34 years, and 3.34 and 2.58 at the age of 35-39 years, respectively. In the persons with positive previous low back pain, the prevalence rate of low back pain was 52.6% in the clerical, and 50.2% in the field workers. Odds ratios for low back pain relating to previous low back pain significantly exceeded unity for the clerical employees (OR = 9.53) and the field workers (OR = 10.28), compared to those without a history of previous low back pain. The incidence of stiffness of the shoulder was 48.2% in the clerical and 45.2% in the field workers, and the prevalence rate of low back pain among those with stiffness of the shoulder was 68.5% in the clerical and 65.8% in the field workers. Odds ratio were 3.03 in both groups. Among each age group, the prevalence rate of stiffness of the shoulder with low back pain increased gradually to a maximum in the 45-49 age group of 19%, and then dropped. In those with a history of low back pain and/or stiffness of the shoulder, the prevalence of low back pain showed significantly greater value than other risk factors.

The effect of complex dynamic lifting and lowering characteristics on trunk muscles recruitment

A better understanding of how the neuromuscular spinal system behaves during lifting and lowering could provide more insight about potential causes of occupational low back disorders (LBDs), and could help in the prevention and rehabilitation process of these disorders. The purpose of this study was to quantify trunk muscle activities under various whole-body free-dynamic symmetric and asymmetric complex lifting and lowering tasks. Eleven male subjects with no prior history of LBDs participated in the study. Electromyographic activities of ten trunk muscles were monitored while subjects either symmetrically or asymmetrically lifted and lowered a box under three different speeds and three weights. The results showed that all ten muscles were responsive to various experimental conditions with the erector spinae and internal oblique muscles showing the greatest response. Substantial electromyographic activities were observed in muscles that were on the contralateral side of the load. Lowering conditions yielded consistently lower muscular activities than their corresponding lifting conditions. These results show that it is essential to consider multiple trunk muscles in modeling efforts of quantifying spinal loading, as well as for back rehabilitation research purposes.