Effectiveness of three interventions for secondary prevention of low back pain in the occupational health setting - a randomised controlled trial with a natural course control.

BACKGROUND: We assessed the effectiveness of three interventions that were aimed to reduce non-acute low back pain (LBP) related symptoms in the occupational health setting. METHODS: Based on a survey (n = 2480; response rate 71%) on LBP, we selected a cohort of 193 employees who reported moderate LBP (Visual Analogue Scale VAS > 34 mm) and fulfilled at least one of the following criteria during the past 12 months: sciatica, recurrence of LBP ≥ 2 times, LBP ≥ 2 weeks, or previous sickness absence. A random sample was extracted from the cohort as a control group (Control, n = 50), representing the natural course of LBP. The remaining 143 employees were invited to participate in a randomised controlled trial (RCT) of three 1:1:1 allocated parallel intervention arms: multidisciplinary rehabilitation (Rehab, n = 43); progressive exercises (Physio, n = 43) and self-care advice (Advice, n = 40). Seventeen employees declined participation in the intervention. The primary outcome measures were physical impairment (PHI), LBP intensity (Visual Analogue Scale), health related quality of life (QoL), and accumulated sickness absence days. We imputed missing values with multiple imputation procedure. We assessed all comparisons between the intervention groups and the Control group by analysing questionnaire outcomes at 2 years with ANOVA and sickness absence at 4 years by using negative binomial model with a logarithmic link function. RESULTS: Mean differences between the Rehab and Control groups were - 3 [95% CI -5 to - 1] for PHI, - 13 [- 24 to - 1] for pain intensity, and 0.06 [0.00 to 0.12] for QoL. Mean differences between the Physio and Control groups were - 3 [95% CI -5 to - 1] for PHI, - 13 [- 29 to 2] for pain intensity, and 0.07 [0.01 to 0.13] for QoL. The main effects sizes were from 0.4 to 0.6. The interventions were not effective in reducing sickness absence. CONCLUSIONS: Rehab and Physio interventions improved health related quality of life, decreased low back pain and physical impairment in non-acute, moderate LBP, but we found no differences between the Advice and Control group results. No effectiveness on sickness absence was observed. TRIAL REGISTRATION: Number NCT00908102 Clinicaltrials.gov.

Sex-specific compensatory growth in the larvae of the greater wax moth Galleria mellonella.

Deficiency of food resources in ontogeny is known to prolong an organism's developmental time and affect body size in adulthood. Yet life-history traits are plastic: an organism can increase its growth rate to compensate for a period of slow growth, a phenomenon known as 'compensatory growth'. We tested whether larvae of the greater wax moth Galleria mellonella can accelerate their growth after a fast of 12, 24 or 72 h. We found that a subgroup of female larvae showed compensatory growth when starved for 12 h. Food deficiency lasting more than 12 h resulted in longer development and lower mass gain. Strength of encapsulation reactions against a foreign body inserted in haemocoel was the weakest in females that showed compensatory growth, whereas the strongest encapsulation was recorded in the males and females that fasted for 24 and 72 h. More specifically, we found sex-biased immune reactions so that females had stronger encapsulation rates than males in one group that fasted for 72 h. Overall, rapidly growing females had a short larval development period and the shortest adult lifespan. These results suggest that highly dynamic trade-offs between the environment, life-history traits and sex lead to plasticity in developmental strategies/growth rates in the greater wax moth.

Cost-effectiveness of providing patients with information on managing mild low-back symptoms in an occupational health setting.

BACKGROUND: Evidence shows that low back specific patient information is effective in sub-acute low back pain (LBP), but effectiveness and cost-effectiveness (CE) of information in early phase symptoms is not clear. We assessed effectiveness and CE of patient information in mild LBP in the occupational health (OH) setting in a quasi-experimental study. METHODS: A cohort of employees (N = 312, aged <57) with non-specific, mild LBP (Visual Analogue Scale between 10-34 mm) was selected from the respondents of an employee survey (N = 2480; response rate 71 %). A random sample, representing the natural course of LBP (NC, N = 83; no intervention), was extracted as a control group. Remaining employees were invited (181 included, 47 declined, one excluded) into a randomised controlled study with two 1:1 allocated parallel intervention arms ("Booklet", N = 92; "Combined", N = 89). All participants received the "Back Book" patient information booklet and the Combined also an individual verbal review of the booklet. Physical impairment (PHI), LBP, health care (HC) utilisation, and all-cause sickness absence (SA) were assessed at two years. CE of the interventions on SA days was analysed by using direct HC costs in one year, two years from baseline. Multiple imputation was used for missing values. RESULTS: Compared to NC, the Booklet reduced HC costs by 196€ and SA by 3.5 days per year. In 81 % of the bootstrapped cases the Booklet was both cost saving and effective on SA. Compared to NC, in the Combined arm, the figures were 107€, 0.4 days, and 54 %, respectively. PHI decreased in both interventions. CONCLUSIONS: Booklet information alone was cost-effective in comparison to natural course of mild LBP. Combined information reduced HC costs. Both interventions reduced physical impairment. Mere booklet information is beneficial for employees who report mild LBP in the OH setting, and is also cost saving for the health care system. TRIAL REGISTRATION: ClinicalTrials.gov NCT00908102.

The effectiveness of two active interventions compared to self-care advice in employees with non-acute low back symptoms: a randomised, controlled trial with a 4-year follow-up in the occupational health setting.

OBJECTIVE: Evaluate the effectiveness of two active interventions, aimed at secondary prevention of low back pain (LBP), in occupational health. METHODS: We performed a survey of LBP (n=2480; response rate 71%) and randomized 143 employees (66% males, 45 years) with LBP over 34 mm on VAS into Rehabilitation (n=43), Exercise (n=43) or self-care (n=40) groups. Primary outcomes were LBP, physical impairment (PI) and health-related quality of life (HRQoL) for two years and sickness absence (SA) days during four years (LBP specific, total). RESULTS: Compared to self-care, exercise reduced LBP at 12 months (mean difference (MD) -12 mm; 95% CI -21 to -2) and improved HRQoL at 12 and 24 months (0.03; 0.00 to 0.05), but did not reduce PI. The MDs of SA days in four years were -17 (-70 to 35, total) and -15 (-47 to 13, LBP specific). Exercise reduced the probability of LBP specific SA during the third and fourth year. Compared to self-care, Rehabilitation reduced LBP at 3 months (-10 mm; -19 to -1) and 6 months (-10 mm; -20 to - 1), but was not effective in HRQoL or PI. The MDs of SA days in four years were -41 (-93 to 8; total) and 5 (-30 to 47; LBP specific). Rehabilitation reduced the probability of total SA during first and second year and amount of total SA days in the fourth year. CONCLUSIONS: Among employees with relatively mild LBP, both interventions reduced pain, but the effects on SA and PI were minor. Exercise improved HRQoL. The effect sizes were rather small. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT00908102.

Traumatic spinal cord injury as a complication to ankylosing spondylitis. An extended report.

OBJECTIVE: Käpylä Rehabilitation Centre is in Finland the only unit taking care of the subacute rehabilitation activities of patients with spinal cord injury (SCI). The annual incidence of new patients with SCI is 55 (1.1 per 100,000 inhabitants). The ankylosed spine (AS) is reported to be at greater risk for fracture and SCI. The aim of the study was to clarify if this higher risk of ankylosing spondylitis (AS) could also be detected among patients with traumatic SCI rehabilitated at Käpylä Rehabilitation Centre. Further, the aim was to evaluate the characteristics of patients with traumatic SCI as a complication to AS in order to develop prevention of SCI in patients with AS. METHODS: Patient data was gathered from the patient register covering all Finnish patients with traumatic SCI (n = 1,103) rehabilitated at Käpylä Rehabilitation Centre from the year 1979 to 1998. The patient journals were subjected to a detailed and systematic analysis. Data about patients with a history of AS (n = 19; 18 men, 1 woman) was then compared to the data about all the patients with SCI (n = 1,103; 902 men, 201 women). RESULTS: Based on the national prevalence data, the incidence rate of patients with AS for traumatic SCI was found to be 11.4 times greater than expected for the population at large. The mean age of the patients with AS was clearly higher (55.3 yrs) than the mean age of the whole group of patients (36.4 yrs) with traumatic SCI. The neurologic injury was at the cervical level in 84% of the patients with AS, but only in 48% of the patients with traumatic SCI in general. Among the patients with AS, the SCI was caused by slipping in 53% of the cases, whereas slipping was the reason for SCI only in 7% of the cases in general. CONCLUSION: Patients with AS seem to run a higher risk of traumatic SCI than the people at large, and the injury levels are higher. In particular, male patients with advanced AS should be instructed to install preventive devices such as night lights and handrails, supports or head rests when driving a car, and they should avoid walking on slippery surfaces, loose carpets etc. They also should be encouraged to avoid excessive use of alcohol and activities involving the risk of physical injury such as contact sports.

The effect of lumbar fatigue on the ability to sense a change in lumbar position. A controlled study.

STUDY DESIGN: A cross-sectional study in patients with recurrent/chronic low back trouble and healthy control subjects. OBJECTIVE: To evaluate the effect of paraspinal muscle fatigue on the ability to sense a change in lumbar position. SUMMARY OF BACKGROUND DATA: Protection against spinal injury requires proper anticipation of events, appropriate sensation of body position, and reasonable muscular responses. Lumbar fatigue is known to delay lumbar muscle responses to sudden loads. It is not known whether the delay is because of failure in the sensation of position, output of the response, or both. METHODS: Altogether, 106 subjects (57 patients with low back trouble [27 men and 30 women] and 49 healthy control subjects [28 men and 21 women]) participated in the study. Their ability to sense a change in lumbar position while seated on a special trunk rotation unit was assessed. A motor rotated the seat with an angular velocity of 1 degree per second. The task in the test involved reacting to the perception of lumbar movement (rotation) by releasing a button with a finger movement. The test was performed twice, before and immediately after a fatiguing procedure. During the endurance task, the participants performed upper trunk repetitive extensions against a resistance, with a movement amplitude adjusted between 25 degrees flexion and 5 degrees extension, until exhaustion. RESULTS: Patients with chronic low back trouble had significantly poorer ability than control subjects on the average to sense a change in lumbar position (P = 0.007), which was noticed before and after the fatiguing procedure. Lumbar fatigue induced significant impairment in the sensation of position change (P < 0.000001). CONCLUSIONS: Lumbar fatigue impairs the ability to sense a change in lumbar position. This feature was found in patients and control subjects, but patients with low back trouble had poorer ability to sense a change in lumbar position than control subjects even when they were not fatigued. There seems to be a period after a fatiguing task during which the available information on lumbar position and its changes is inaccurate.

Mechanisms explaining the association between low back trouble and deficits in information processing. A controlled study with follow-up.

STUDY DESIGN: A controlled study with a 6-month follow-up period. OBJECTIVES: To find an explanation for the association between impairment in information processing, i.e., slow reaction times, and chronic low back trouble. SUMMARY OF BACKGROUND DATA: Low back trouble, chronic pain in general, and depression have been associated with impaired cognitive functions and slow reaction times. It is a common phenomenon that the preferred hand performs better than the nonpreferred hand in motor tasks. The authors hypothesized that chronic low back trouble hampers the functioning of short-term memory in a way that leads the preferred hand to loose its advantage over the nonpreferred hand, but that the advantage would be restored during the rehabilitation. METHODS: Sixty-one healthy control subjects and 68 patients with low back trouble participated in the study. Reaction times for the preferred and nonpreferred upper limbs were tested. A multiway analysis of covariance was used to examine the group, handedness, and rehabilitation effects on reaction times. The hypothesis was specifically tested with a third-degree interaction: group-handedness-rehabilitation. RESULTS: A significant interaction among group, handedness, and rehabilitation was found (P = 0.05). At the beginning, the reaction times for the preferred hand were faster among the control subjects (P = 0.001), but not among the patients with low back trouble (P = 0.62). After the rehabilitation, the preferred hand was faster both among the control subjects (P = 0.001) and the patients with low back trouble (P = 0.0002). During the rehabilitation, back pain, psychological distress, and general disability decreased significantly among the patients with chronic low back trouble. CONCLUSIONS: The results support the hypothesis that chronic low back trouble (i.e., pain, psychological distress, and general disability) hampers the functioning of short-term memory, which results in decreased speed of information processing among patients with chronic low back trouble.

One-footed and externally disturbed two-footed postural control in patients with chronic low back pain and healthy control subjects. A controlled study with follow-up.

STUDY DESIGN: A study of postural control during one-footed and externally disturbed two-footed stance among healthy control subjects and patients with chronic low back pain at the beginning of a functional back restoration program and 6 months later at follow-up examination. OBJECTIVES: To study postural control cross-sectionally among control subjects and patients with low back pain, and to evaluate the effects of functional restoration on the postural control parameters in a follow-up examination. SUMMARY OF BACKGROUND DATA: Deficits of motor skills and coordination have been reported in association with musculoskeletal disorders. It has been found that patients with chronic low back pain have impaired psychomotor control, but the impairment is reversible with successful low back rehabilitation. It is insufficiently known how functional activation and intensive physical training affect postural control. METHODS: Sixty-one healthy volunteers (32 men, 29 women) and altogether 99 patients with low back pain participated in the study. Sixty-eight patients (33 men, 35 women) had moderate and 31 (18 men, 13 women) had severe low back pain. Postural stability was measured with a force platform. In two-footed stance, vibration stimulation on calf and back muscles was used to disturb the balance. Center point of force-velocity (cm/sec), average position shift in anteroposterior direction (cm), and maximal position shift in lateral direction (cm) were used as the parameters. RESULTS: Reliability of all tests was acceptable. Center point of force-velocity was the most sensitive parameter and the one-footed measurement the most sensitivetest for evaluating postural stability. At the beginning, the patients with severe low back pain had poorer one-footed postural control compared with the control subjects (P = 0.0003). The subgroup of patients with moderate low back pain participated in the restoration program. The outcome of the restoration program was considered good if the disability because of low back pain (Oswestry index) decreased during the restoration program and poor if the disability increased or did not change. The one-footed postural stability remained primarily at the same level as the initial results in the control and good outcome groups, but became significantly poorer in the poor outcome group. The difference between poor outcome and control groups was statistically significant (P = 0.04). CONCLUSIONS: Impaired postural stability seems to be one factor in multidimensional symptomatology of patients with chronic low back trouble. Postural stability is easily disturbed in case of impairment in strength, coordination, or effective coupling of muscles in the lumbar and pelvic area. Patients with chronic low back pain seem to experience impairment in these functions, which should be taken into consideration when back rehabilitation programs are planned.

Psychomotor speed in chronic low-back pain patients and healthy controls: construct validity and clinical significance of the measure.

The effect of ethanol on reaction times was studied in 5 healthy men to test the construct validity of the measure. Reaction times were studied among 61 healthy controls and 99 patients with chronic low-back pain (68 moderate and 31 severe) to evaluate the diagnostic value of reaction time measurements. Analysis of receiver operating characteristics was used to calculate the discriminative power of the reaction time measurements. The severity of low-back pain was associated with slow reaction times but the diagnostic value of a single reaction time measurement was low due to insufficient sensitivity. In conclusion, even though many patients with low-back pain suffer from central impairment of motor function, a single reaction time measurement is not usable in evaluation of the severity of low-back pain.

Arm motion speed and risk of neck pain. A preliminary communication.

STUDY DESIGN: A sample of 486 Helsinki City Council workers, 35 to 54 years of age, was examined twice at a 1-year interval. OBJECTIVES: To investigate the speed of repetitive arm motion for its ability to predict neck pain. SUMMARY OF BACKGROUND DATA: Psychomotor factors have been suggested to play a role in the etiology of spinal disorders. It was hypothesized that motor skills, as reflected by arm motion speed, could provide protection against neck pain. METHODS: Both the baseline and follow-up examinations consisted of a questionnaire on the history of neck pain and of a number of tests, including arm motion speed and static and dynamic strength of the upper extremities. RESULTS: Of the 124 men and women who reported not having had neck pain during the 1 year before the baseline examination, 23 (19%) reported neck pain on reexamination. The incidence of neck pain was significantly higher both in the least and most rapid quintiles of arm motion speed than in the medium quintiles. This association was not confounded by age, sex, smoking, physical activity at work or at leisure, psychological distress score, or strength measures of the upper extremities, although these factors were significant covariates of the arm motion speed at baseline. When adjusted for these factors, the odds ratios of neck pain in the most and least rapid quintiles of arm motion speed were 8.68 (95% confidence interval 1.85-40.75) and 9.57 (95% confidence interval 2.21-41.52) respectively, compared with the medium quintiles. CONCLUSIONS: These results suggest that people with either very slow or very rapid arm motion speed may have an increased risk of neck pain. The etiology of neck pain is probably different on these two occasions.

Low synthesis rate of type I procollagen is normalized during active back rehabilitation.

STUDY DESIGN: Open, prospective trial with patients participating in an active back restoration program. OBJECTIVES: To compare the concentrations of biochemical indicators of Type I and III collagen synthesis and Type I collagen degradation in the serum of patients with chronic low back pain and healthy control subjects and to evaluate the effect of active back rehabilitation based on vigorous exercise on collagen metabolism. SUMMARY OF BACKGROUND DATA: The aim of active back rehabilitation is to restore the physical function of low back pain patients falling into the so-called "deconditioning syndrome." The changes in functional muscle strength measurements during the restoration rehabilitation program always depend on motivation, learning phenomena, and fear of pain and injury, so that even more objective ways of showing changes in physical activity are needed. METHODS: Specific radioimmunoassays for the amino-terminal (PINP) and carboxy-terminal (PICP) propeptides of Type I procollagen, the amino-terminal propeptide of Type III procollagen (PIIINP), and the cross-linked carboxy-terminal telopeptide of Type I collagen (ICTP) were used for serum samples obtained from 41 patients before, during, and after an active back restoration program and from 16 age- and sex-matched healthy control subjects. RESULTS: The circulating concentrations of PINP and PICP were initially lower in the patients ([mean +/- SD] 35.3 +/- 12.5 micrograms/L and 119.0 +/- 32.6 micrograms/L, respectively) than in the control subjects (47.9 +/- 18.0 micrograms/L and 136.7 +/- 47.7 micrograms/L, respectively; P < 0.05 for PINP). Toward the end of the active back rehabilitation program, both PINP and PICP increased in the patients (P < 0.001 for the increase between the initial level and the end of rehabilitation). There was a significant difference in the time courses of these changes, with the circulating PICP concentration increasing earlier than that of PINP. In the intervention group, the PIIINP concentration also increased (P < 0.01), whereas the ICTP concentration remained unchanged, with a tendency to decrease. No changes occurred in the control subjects. CONCLUSIONS: Active back rehabilitation based on vigorous exercise increases. Type I collagen synthesis in patients with chronic low back pain; this may provide a means of objectively verifying the effects of such rehabilitation.

Isokinetic performance capacity of trunk muscles. Part II: Coefficient of variation in isokinetic measurement in maximal effort and in submaximal effort.

It has been claimed that with the aid of isokinetic trunk strength measuring devices it is possible to distinguish true muscular weakness from submaximal effort in the test. This proposition is based on the presumption that in the isokinetic trunk strength test identical performances can only be reproduced by maximal effort. The purpose of this study was to investigate whether it is possible to distinguish maximal effort from submaximal with the aid of the coefficient of variation (CV) in an isokinetic trunk muscle strength test. The study group included 35 (21 male and 14 female) subjects of whom 12 were healthy, 10 had a mild low-back pain and 13 had a more severe chronic low-back pain. The subjects performed five consecutive bendings both with maximal (100%) and submaximal (50%) efforts at a speed of 90 degrees/second. In maximal effort only healthy subjects reached an average level of CV close to 10% both in extension and in flexion. In the chronic low-back pain group the average CV was close to 20%. The difference in CV was statistically significant (p < 0.05-0.02) between the healthy and the chronic low-back pain subjects. In the submaximal effort all health groups had a CV of approximately 20% or more and no significant differences were found. The group of slightly variable measurements (CV = 11-20%) was remarkably large in both the maximal and submaximal effort. The results suggest that an effort with a CV of 11-20% cannot be classified as definitely submaximal or maximal. When the CV is less than 10% the effort can be fairly certainly classified as maximal.

Isokinetic performance capacity of trunk muscles. Part I: The effect of repetition on measurement of isokinetic performance capacity of trunk muscles among healthy controls and two different groups of low-back pain patients.

The aim of this investigation was to assess the reproducibility of the isokinetic trunk muscle performance measurement among patients with different degrees of low-back pain. Twenty-two healthy volunteers, 20 patients with mild and 18 patients with severe low-back pain participated in isokinetic measurements. Lidoback isokinetic dynamometer was used. The measurements were performed with the subjects standing, using velocities of 60, 90 and 120 degrees/second. Five repetitions were performed at each velocity. All subjects were tested three times with a 1-week interval between the tests. Peak torque, average peak torque, coefficient of variation, total work done and peak torque to body weight ratio were calculated for each velocity for both flexion and extension. The results showed that in every measurement peak torque, average peak torque, peak torque to body weight ratio and total work done correlated with each other very strongly both in flexion and extension (r > or = 0.9). The average peak torques increased in further measurements. The change had a strong correlation with the severity of the back problem, which was evaluated by means of the Oswestry disability index. The critical value was found to be 20% in the Oswestry index: values above this meant big changes between measurements and values below this meant small changes between measurements.

Psychomotor speed and postural control in chronic low back pain patients A controlled follow-up study.

STUDY DESIGN: Psychomotor speed (reaction time) and postural control (center point of force velocity) among healthy control volunteers and patients with chronic low back pain (LBP) were studied at the beginning of an active, functional, restoration back rehabilitation program and 5 months after the program. OBJECTIVES: To study cross-sectionally reaction times and center points of force velocity among control volunteers and patients with low back pain, and to evaluate the effects of the restoration on these measures of motor function in a follow-up examination. SUMMARY OF BACKGROUND DATA: Deficits of motor skills and of coordination have been reported in association with musculoskeletal disorders, but one can only speculate about an association between proprioceptive dysfunction and low back disorders on the basis of the currently available data. METHODS: Sixty-one healthy control volunteers and 99 patients with low back pain-68 of these patients experienced moderate pain; 31 experienced severe pain-participated in the study. Reaction times for upper and lower limbs were tested with a system based on a microcomputer. Postural stability was measured with a vertical force platform. RESULTS: A consistent trend was found in which patients with low back pain had reaction times slower than these of control volunteers. Man with severe low back pain had significantly longer hand reaction times than men in the control group (P = 0.03). Women with severe low back pain also had poorer postural control than women with moderate low back pain (P = 0.02) and women in the control group (P = 0.04). Functional restoration seemed to have an effect on reaction times. The restoration was considered successful if the condition of a patient with a disability that had resulted from low back pain improved during the follow-up examination and unsuccessful if the disability worsened. Patients who experienced these results were identified in groups called "good" and "poor," respectively. Among men, the reaction times improved in the control group and "good" groups, but they became slower in the "poor" group. The difference between "good" and "poor" groups was significant (P = 0.008). Women in the "good" group achieved the most improved reaction times, and the difference between these women and the control women almost reached significance (P = 0.076). CONCLUSION: The results indicate that patients with chronic low back pain have impaired psychomotor speed and, among women, impaired postural control. Psychomotor speed improved during an active, functional, restoration back rehabilitation program.

Static back endurance and the risk of low-back pain.

Spinal physical capacity and in particular static back endurance were studied for their prediction of first-time experience of low-back pain. Of a total of 126 persons who were free from back complaints at entry, 33 developed low-back pain during a follow-up of 1 year. The static back endurance test was found to be the only physical capacity measurement that indicated an increased risk of low-back pain. Adjusted for age, sex, and occupation, the odds ratio of a new low-back pain in those with poor performance was 3.4 (95% confidence interval, 1.2-10.0) compared to those with medium or good performance. RELEVANCE--:The simple static back endurance test might have value in health examinations because of its strong predictive value of future low-back pain.

Ophthalmological findings in nephropathia epidemica in Lapland.

We report ophthalmological findings in 15 cases of nephropathia epidemica. The patients, 13 men and 2 women, were 20 to 62 (mean 30) years of age. The onset of the disease was characterized by high fever, nausea, headache, abdominal pain, backache, somnolence, red throat, proteinuria, and oliguria. The symptoms subsided rapidly during the polyuria stage. Transitory myopia occurred in 8 patients (53%). Conjunctival injection and haemorrhages were seen in 3 patients (20%). One patient had acute glaucoma with oedema in the cornea and shallowing of the anterior chamber, with subsequent anterior uveitis and haemorrhages in the ocular fundus, and another patients had acute glaucoma. Three patients had photophobia which occurred in 2 patients without any glaucoma or anterior uveitis.