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.

Association between adolescent sport activities and lumbar disk degeneration among young adults.

The relationship between different sport activities and lumbar intervertebral disk degeneration (DD) is largely unknown. We evaluated whether adolescent participation in different sports is associated with lumbar DD in a population-based birth cohort of young adults. A total of 558 young adults (325 females and 233 males) underwent magnetic resonance imaging (MRI, 1.5-T scanner). A DD sum score, based on the Pfirrmann grading, was calculated for all lumbar levels. The sum score was categorized into no DD, 1, 2, or at least 3. Participation in different sport activities was self-reported by postal surveys at 16, 18, and 19 years, and three groups were formed based on participation frequency in 11 sports: (a) highly active (at least twice a week), (b) moderately active (2-4 times a month), and (c) inactive (maximum once a month). Cumulative odds ratios (COR) and their 95% confidence intervals (CI) were obtained for each sport by ordinal logistic regression, adjusting for gender, body mass index, age, socioeconomic status, smoking, and other sports. Highly active participation in jogging/running and swimming was associated with a higher DD sum score (COR: 3.0; 95% CI: 1.4-6.3 and 5.0; 1.7-15.2, respectively) compared to inactive participation, whereas highly active participation in skating showed low COR. In conclusion, running and swimming at least twice a week in early adulthood are potentially associated with lumbar DD. Follow-up studies with MRI are needed to show whether frequent exposure to running or swimming has further effect on the integrity of lumbar intervertebral disks.

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.

An occupational health intervention programme for workers at high risk for sickness absence. Cost effectiveness analysis based on a randomised controlled trial.

OBJECTIVES: To determine whether, from a healthcare perspective, a specific occupational health intervention is cost effective in reducing sickness absence when compared with usual care in occupational health in workers with high risk of sickness absence. METHODS: Economic evaluation alongside a randomised controlled trial. 418 workers with high risk of sickness absence from one corporation were randomised to intervention (n = 209) or to usual care (n = 209). The subjects in the intervention group were invited to occupational health service for a consultation. The intervention included, if appropriate, a referral to specialist treatment. Register data of sickness absence were available for 384 subjects and questionnaire data on healthcare costs from 272 subjects. Missing direct total cost data were imputed using a two-part regression model. Primary outcome measures were sickness absence days and direct healthcare costs up to 12 months after randomisation. Cost effectiveness (CE) was expressed as an incremental CE ratio, CE plane and CE acceptability curve with both available direct total cost data and missing total cost data imputed. RESULTS: After one year, the mean of sickness absence was 30 days in the usual care group (n = 192) and 11 days less (95% CI 1 to 20 days) in the intervention group (n = 192). Among the employees with available cost data, the mean days of sickness absence were 22 and 24, and the mean total cost euro974 and euro1049 in the intervention group (n = 134) and in the usual care group (n = 138), respectively. The intervention turned out to be dominant-both cost saving and more effective than usual occupational health care. The saving was euro43 per sickness absence day avoided with available direct total cost data, and euro17 with missing total cost data imputed. CONCLUSIONS: One year follow-up data show that occupational health intervention for workers with high risk of sickness absence is a cost effective use of healthcare resources.

The effectiveness of two occupational health intervention programmes in reducing sickness absence among employees at risk. Two randomised controlled trials.

OBJECTIVES: To evaluate the effectiveness of two occupational health intervention programmes, both compared with usual care. METHODS: Based on a health survey, 1341 employees (88% males) in construction, service and maintenance work were classified into three groups: "low risk" (n = 386), "intermediate risk" (n = 537) and "high risk" (n = 418) of sickness absence. Two separate randomised trials were performed in the groups "high risk" and "intermediate risk", respectively. Those high risk subjects that were allocated to the intervention group (n = 209) were invited to occupational health service for a consultation. The intervention included, if appropriate, a referral to specialist treatment. Among the intermediate risk employees those in the intervention group (n = 268) were invited to call a phone advice centre. In both trials the control group received usual occupational health care. The primary outcome was sickness absence during a 12-month follow-up (register data). RESULTS: The high risk group, representing 31% of the cohort, accounted for 62% of sickness absence days. In the trial for the high risk group the mean sickness absence was 30 days in the usual care group and 19 days in the intervention group; the mean difference was 11 days (95% CI 1 to 20 days). In the trial for the intermediate risk group the mean sickness absence was 7 days in both arms (95% CI of the mean difference -2.3 to 2.4 days). CONCLUSIONS: The identification of high risk of work disability was successful. The occupational health intervention was effective in controlling work loss to a degree that is likely to be economically advantageous within the high risk group. The phone advice intervention for the intermediate risk group was not effective in controlling work loss primarily due to poor adherence.

Effects of a long acting somatostatin analog on pituitary, adrenal, and testicular function during rest and acute exercise: unexpected stimulation of testosterone secretion.

The purpose of this study was to delineate the possible endocrine effects of exercise-induced GH secretion. Twelve healthy adult males were studied during short (20 min) and subsequent prolonged (2 h) physical exercise and recovery period (2 h), both after injection of a long acting somatostatin analog [Sandostatin (ST); 0.1 or 0.05 mg, sc] and after a control saline injection. Additional subjects were studied during rest with similar injections of ST (0.1 mg) and saline (n = 7) or using a lower ST dose (0.01 mg; n = 6). Several venous blood samples were taken during the trials and analyzed for selected hormones, monitoring pituitary, testicular, and adrenal functions. ST injection blocked the serum GH response to short term maximal bicycle ergometer exercise, but not to the following prolonged bicycle exercise. No relationship of the exercise-associated GH increase to the concomitant endocrine responses of the adrenals and testes was observed. Unexpectedly, the higher ST doses (0.1 and 0.05 mg) increased the mean levels of serum testosterone by 18-25% in both exercise (P = 0.0017) and rest trials (P < 0.0001), respectively. ST did not affect the levels of LH, FSH, or cortisol. ST slightly increased serum sex hormone-binding globulin (3%; P = 0.021) and albumin (4%; P = 0.017) concentrations, but not that of free testosterone. Because the testosterone response to somatostatin was fast and without a simultaneous increase in LH, it was consistent with a direct testicular response. The explanation for this novel ST effect remains obscure, but it may be due to modulation of some paracrine mechanisms inhibiting testicular steroidogenesis.

Prevalence of hyperapobetalipoproteinemia and factors affecting the phenotype expression in children and young adults. The Cardiovascular Risk in Young Finns Study.

Hyperapobetalipoproteinemia (hyperapoB) is one of the most common phenotypes in patients with premature coronary heart disease. In this study the factors that affect the expression of the hyperapoB phenotype were evaluated in young individuals. A cohort of 1125 children and young adults aged 9-24 years was classified into three groups by sex: (1) normal serum apolipoprotein B (apoB), (2) high apoB (> or = 90th percentile) and normal low density lipoprotein cholesterol (LDL-C < 90th), (3) high apoB and high LDL-C (> or = 90th percentile). In females, alcohol use (11, 33, 0%, in groups 1-3, P < 0.05) and oral contraceptive use (35, 83, 47%, P < 0.01) were significantly different between the groups and the highest frequencies were seen in the hyperapoB group (group 2). In both sexes smoking tended to be more common in the hyperapoB group (29, 43, 18%, P < 0.14). The two hyperapoB definition criteria (high apoB and low LDL-C/apoB ratio) were studied with multiple linear regression analyses. Oral contraceptive use correlated positively with apoB values (coefficient beta = 0.101, R2 = 2.1%, P < 0.01) and negatively with LDL-C/apoB ratio (beta = -0.134, R2 = 3.3%, P < 0.001). Alcohol use (beta = -0.072, R2 = 2.9%, P < 0.001) and smoking (beta = -0.050, R2 = 1.0%, P < 0.05) correlated negatively with LDL-C/apoB ratio. Prevalence of the hyperapoB phenotype was 4.4%. According to the results, the expression of the hyperapoB phenotype may be influenced by common lifestyle habits. This should be considered if high risk young individuals are identified through the expression of the hyperapoB phenotype.

Influence of parental occupation on coronary heart disease risk factors in children. The Cardiovascular Risk in Young Finns Study.

BACKGROUND: The influence of parental occupation on selected coronary heart disease risk factors was studied in a cohort of Finnish children aged 9, 12 and 15 years (n = 1211) as part of the Cardiovascular Risk in Young Finns Study in 1986. METHODS: The relationships of parental occupation to serum lipid and apolipoprotein concentrations, blood pressure, obesity, smoking, physical activity, diet and birthweight were examined. The occupation of the parents was obtained by a questionnaire and classified as I: upper non-manual (22%), II: lower non-manual (26%), III: upper manual (32%), IV: lower manual (5%) and F: farmers (15%). RESULTS: Highest serum total and how density lipoprotein cholesterol concentrations were found in classes IV and F. Boys from class IV had 7.1% higher total cholesterol concentrations compared to class I (4.98 mmol/l versus 4.65 mmol/l, P = 0.0033), whereas farmers' girls had 10.4% higher concentrations than girls from class III (5.31 mmol/l versus 4.81 mmol/l, P = 0.0057). Blood pressure was related to parental occupation only in boys, and the values were highest in class F. Boys from class IV smoked most often, and they also had lowest values for physical activity index and highest obesity indices. Farmers' children consumed significantly more saturated fat and cholesterol than children from other classes. In boys, the percentage of subjects with a low birthweight (< or = 10th percentile) was smallest in class I and greatest in class IV (7.1% versus 20.7%, P = 0.0330). CONCLUSIONS: Socioeconomic status based on parental occupation is associated with several coronary heart disease risk factors already present in children. These differences should be taken into account in prevention programmes aimed at children at an increased risk for developing coronary heart disease as adults.

Associations of education with cardiovascular risk factors in young adults: the Cardiovascular Risk in Young Finns Study.

BACKGROUND: Low educational level is associated with an increased risk of coronary heart disease. The aim of the present study was to examine the relationships between education and common cardiovascular risk factors in young adults. METHODS: Trends in conventional risk factors of young adults aged 21, 24, 27 and 30 years in 1992 (n = 443) were examined across the educational groups as part of a 12-year follow-up study, the Cardiovascular Risk in Young Finns Study. Education was determined as participants' own educational level and as parental years of schooling. RESULTS: In males, subject's own education was related inversely and independently of parental school years to serum total and low density lipoprotein (LDL) cholesterol concentration, smoking and body mass index. In females, participant's own educational level associated inversely with smoking and physical inactivity. Parental school years was associated inversely and independently of one's own educational level with serum total and LDL cholesterol values and waist-hip ratio in females. In both genders, parental education was a stronger determinant of diet (butter use) than one's own educational level. CONCLUSIONS: The least educated young adults have adopted a more adverse lifestyle than the more educated. The risk factor profile in young adulthood, especially in females, is still affected by parental education. The influences of one's own and parental educational level on vascular risk profile should be taken into consideration when planning public health campaigns among young adults.

Prevalence of diabetes, hypertension, and ischemic heart disease in former elite athletes.

Diabetes, hypertension, and ischemic heart disease are less frequent among physically active subjects. The aim of the present national population-based study was to compare the prevalence of these three diseases between former Finnish elite athletes and referents. The subjects consisted of surviving former male athletes who represented Finland between the years 1920 and 1965 at least once in international competitions and referents who at the age of 20 were classified as completely healthy at a medical examination, and who responded to a questionnaire in 1985 (athletes, n = 1,282; referents n = 777). In 1985, they completed a questionnaire with medical, life-style, and psychosocial items; at that time, the leisure physical activity was greater in previous athletes than in referents. The presence or absence of the three diseases was identified from the questionnaire or from at least one of three registers: Finnish hospital inpatient discharge register, reimbursable medication register, and disability pension register. When compared with referents, both endurance and mixed-sports athletes had lower age-adjusted odds ratios (ORs) for all studied diseases. Compared with referents, power-sports athletes had a higher risk for high body mass index (BMI) but a lower risk for ischemic heart disease. Subjects with high BMI had an increased risk for all three diseases. Smokers had a higher risk for diabetes and ischemic heart disease compared with those who were never smokers. After adjustments for age, BMI, smoking history, and occupational group, compared with referents, former endurance athletes had the lowest ORs for diabetes (OR 0.24; 95% confidence interval, 0.07 to 0.81) and ischemic heart disease (OR 0.33; 0.18 to 0.61).(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of physical activity on serum total and low-density lipoprotein cholesterol concentrations varies with apolipoprotein E phenotype in male children and young adults: The Cardiovascular Risk in Young Finns Study.

Apolipoprotein E (apo E) determines serum total (TC) and low-density lipoprotein (LDL-C) cholesterol concentrations and is thus associated with coronary heart disease (CHD) risk. We studied if the effect of physical activity (PA) on serum TC and LDL-C concentrations varies with apo E phenotype in a population-based sample of children and young adults with regular PA. The study cohort consisted of subjects aged 9, 12, 15, 18, 21, and 24 years in 1986 (N = 1,498) participating in a large multicenter study of cardiovascular risk factors in children and young adults. Serum lipid concentrations were determined enzymatically, and apo E phenotypes by isoelectric focusing and immunoblotting. The composition of the diet was determined by a 48-hour recall method, and a PA index was calculated on the basis of frequency, intensity, and duration of activity assessed by a questionnaire. LDL-C (P = .0082), TC (P = .014), and the high-density lipoprotein cholesterol (HDL-C)/TC ratio (P = .0004) responses to exercise varied with apo E phenotype. The effect of PA on LDL-C, TC, or HDL/TC was not found in apo E phenotype E4/4. A moderate inverse effect of PA on TC and LDL-C and a positive effect on HDL/TC was found in subjects with E4/3 and E3/3 phenotypes. Similar but stronger associations were found between these variables within the group of E3/2 males. The effect of PA on serum lipid levels was strongest within the phenotype E3/2. These associations were not explained by dietary habits. Apo E phenotype partly determines the effect of PA on serum TC and LDL-C in Finnish male children and young adults with regular PA.

Intrinsic risk factors and athletic injuries.

The benefits of physical activity are widely known. However, the risk of a musculoskeletal injury is an unfavourable consequence in physical training. Age, gender, injury history, body size, local anatomy and biomechanics, aerobic fitness, muscle strength, imbalance and tightness, ligamentous laxity, central motor control, psychological and psychosocial factors as well as general mental ability are factors in the predisposition to injury. Junior (15 to 16 years) and senior athletes seem to be at a higher risk of injury in many types of sport. However, the relationship between age and injuries apparently depends on both the type and intensity of activity practiced. The majority of injured athletes in many studies have been males. Men are, however, more likely to participate in vigorous exercise and sport and it is not known if men are at a generally higher risk of injury when the exposure is taken into account. Certain lesions, such as sprains, strains and dislocations, tend to recur. Previous injuries may necessarily not cause a repetition of injury if treated adequately, but certain individuals may be at a higher risk of injury due to injury-prone biological characteristics. Excessive height and weight have been shown to predispose to stress injuries in physical training. Idiopathic or acquired abnormalities in the anatomy or biomechanics in any joint may lead to a local injury. However, physical requirements vary widely between different types of activity and predisposition to injury due to anatomical or biomechanical factors seems to be characteristic for each type of exercise. Lack of fitness, muscle weakness, joint looseness and poor general flexibility have been suggested as factors in the outcome of athletic injuries but no definite conclusions can be made on the basis of the existing literature. Long simple reaction times to visual stimuli and long choice reaction times to visual stimuli have recently been related to musculoskeletal injuries. No exceptional personality dimension in injury proneness as a whole has been found and the results from specific groups cannot be extrapolated generally. Accumulation of life stress apparently predisposes to an athletic injury. Musculoskeletal injuries seem to be more common in subjects with lower scores in intelligence tests but no causation has been shown yet. Altogether, a complex network of risk factors for athletic injuries has been found. However, no prospective study including all the recognised injury risk factors has been presented in the literature.(ABSTRACT TRUNCATED AT 400 WORDS)

Physical activity, VO2max, and jumping height in an urban population.

We studied the interrelations between, on the one hand, the physical activity (frequency, duration, intensity, and mode) measured by a questionnaire and, on the other, VO2max (submaximal bicycle ergometer test) and the explosive muscle strength (vertical jumping height). A random sample of 774 healthy subjects from the city of Turku participated in this study; the subjects were 25, 35, 45, or 55 yr of age. The VO2max of physically active 55-yr-old female subjects was on the same average level as of 25-yr-old females, who were physically inactive. Correspondingly, the average VO2max of physically active 55-yr-old male subjects was above the average level of 25-yr-old males, who were physically inactive. With the exception of the oldest female study group, the jumping test of physically active subjects gave similar results as those of their inactive counterparts who were 10 yr younger. On the basis of the sports events reported by the subjects, we classified the subjects into five activity mode categories. The mode of activity was significantly associated with VO2max in a three-way ANOVA (P = 0.0027) as well as with the jumping test result (P = 0.0001). Mixed training (includes varied types of exercise for the neuromuscular system) was the most beneficial mode of exercise for developing jumping height. The study suggests that the intensity, frequency, and duration of regular physical activity habits during leisure are associated with both VO2max and the jumping height, and that the jumping height results, in particular, are increased by mixed training.

Low-back pain in adolescent athletes.

In this 3-yr longitudinal study we investigated the occurrence of low-back pain and anatomic changes in the low back in relation to loading and injuries among 98 adolescents: 33 nonathletes (16 boys, 17 girls), 34 boy athletes (17 ice hockey, 17 soccer players), and 31 girl athletes (17 figure skaters, 14 gymnasts). During the 3-yr follow-up, low-back pain lasting longer than 1 wk was reported by 29 (45%; 95% CI, 32%-57%) athletes and by 6 (18%; 95% CI, 7%-35%) nonathletes (P = 0.0099). Acute back injury was reported by 17 of 19 subjects who also reported low-back pain (89%; 95% CI, 67%-99%) and by 2 of 63 of those without prolonged low-back pain (3%; 95% CI, 0%-11%) (P < 0.0001). Among 43 girls participating in baseline and follow-up MRI examinations of the lumbar spine, new MRI abnormalities were found in 6 of 8 reporting acute back injury (75%; 95% CI, 35%-97%) and in 8 of the remaining 35 girls (23%; 95% CI 10% to 40%) (P = 0.018). In conclusion, excessive loading that involves a risk for acute low-back injuries during the growth spurt is harmful to the lower back.

Subject characteristics and low back pain in young athletes and nonathletes.

Factors associated with low back pain (LBP) were sought by means of a questionnaire and physical measurements in 138 adolescents. One-hundred athletes and 38 nonathletes, 138 subjects total (58 boys and 80 girls; age range 10.3-13.3 yr), were studied. The questionnaire included questions on physical activity and LBP. Quantitative measurements on anthropometry, flexibility (joint hypermobility and muscular tightness), and strength were performed. There was no significant difference in the occurrence of LBP between athletes and nonathletes. Among the athletes, the duration of training during the past 12 months (min.wk-1) was higher in subjects with the experience of LBP during the past 12 months (N = 23) compared with nonsymptomatic subjects (N = 76) (mean 493 +/- 308 min.wk-1 vs 354 +/- 160 min.wk-1; P less than 0.0001). Similar differences were also seen between subjects with positive lifetime histories of LBP and nonsymptomatic subjects. Various differences were seen in the measurements of anthropometry, flexibility, and strength between boys and girls as well as between athletes and nonathletes. In a multivariate analysis, the cumulative incidence of lifetime history of LBP was associated with tightness of hip flexor muscles only (P = 0.014). LBP during the past 12 months was associated only with the amount of training during the past 12 months (min.wk-1) (P = 0.0066). Our study suggests that high training duration predisposes young athletes to LBP. However, e.g., the flexibility measurements cannot be used to determine athletes at high risk.

Associations between physical activity and risk factors for coronary heart disease: the Cardiovascular Risk in Young Finns Study.

Risk factors such as high serum cholesterol concentration measured in young adulthood predict premature coronary heart disease (CHD) in the middle-aged. The objective of this study was to analyze the associations between physical activity and CHD risk factors--body composition, blood pressure, serum lipids, apolipoproteins, and insulin--in children and young adults. The design was a cross-sectional study of atherosclerosis precursors in children and young adults using a cohort of children and young adults (N = 2,358) aged 9 to 24 years to determine indices of physical activity, measurements of anthropometric characteristics, blood pressure, serum lipids, apolipoproteins A-I and B, and insulin. The results show that a high level of physical activity was associated with high serum high density lipoprotein cholesterol (HDL-C) and HDL2-C concentrations, and low levels of serum triglycerides (TG), apolipoprotein B and insulin in males. However, in females, the influence of physical activity was evident only on TG level. In both genders, physical activity was inversely associated with obesity. In all these associations, a significant dose-related relationship was observed. We found no association between physical activity and blood pressure. In conclusion, physical activity is associated with a favorable serum lipid profile already during childhood and early adulthood in a dose-related manner, particularly in males. The promotion of physical activity is important in childhood in preventing obesity and premature cardiovascular disease.

Stress fracture of the medial malleolus.

We studied eight patients who had a stress fracture of the medial malleolus. The main symptom was localized pain on the medial side of the ankle. The initial radiographs revealed the lesion for only three patients; for the other patients, the diagnosis was made with the use of isotope scans and was confirmed with computerized tomography scans, magnetic resonance images, or subsequent plain radiographs. One vertical fracture was treated initially with compression with AO screws. On the basis of our experience with stress fractures in other bones, drilling was performed to enhance the formation of bone in two patients who had delayed healing and who had had symptoms for eight and twelve months. The fractures healed four and five months after the drilling. The five patients who were managed non-operatively had to avoid running and jumping for at least three months (average, four months) so that healing could take place. All five of these fractures healed within five months.

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.