Effects of external light loading in power-type strength training on muscle power of the lower extremities in middle-aged subjects.

The purpose of this study was to evaluate and compare the effects of training either with a light load or without any load in a 16-week power-type strength training intervention in sedentary middle-aged subjects. A total of 85 subjects participated in the study. In a supervised 22-week training intervention, including 16 weeks of power-type strength training, 42 subjects (Light Load group=LL group) trained with a 1.1 kg weight on each ankle and 43 subjects (No Load group=NOL group) trained without any external load. Subjects were comparable concerning their training attendance, and anthropometric and physiological characteristics. Training effects were evaluated by measuring Vertical Squat Jump (VSJ), 20-metre Running Time (20 mRT), Maximal Anaerobic Cycling Power of leg muscles (MACP), and Maximal Oxygen Uptake (V.O (2 max)) before and after the intervention. The LL group improved VSJ and MACP significantly (p<0.05), compared with the NOL group. No difference between the groups was observed in 20 mRT or in V.O (2 max). To conclude, the external loads of 2.2 kg, in total, increased the efficiency of power-type strength training in vertical jumps and in anaerobic power in leg muscles, but not in sprint running.

Feasibility of power-type strength training for middle aged men and women: self perception, musculoskeletal symptoms, and injury rates.

OBJECTIVES: To examine the feasibility of a power-type strength training programme for middle aged men and women, the impact of the training programme on perceived health and fitness and on knee and low back symptoms, and the rate of exercise induced injuries. METHODS: A total of 154 voluntary, healthy, sedentary men and women participated in a training programme lasting about four months. The explosive force of leg extensor muscles was measured by means of standing long jumps and vertical squat jumps. Perceived health, perceived fitness, and low back and knee symptoms were assessed before and after the intervention by using a questionnaire. Musculoskeletal disorders and exercise induced injuries were reported during the training programme. RESULTS: Perceived fitness improved in both men (p<0.01) and women (p<0.0001), but perceived health only in women (p<0.01). Men with increased explosive force in squat jumping also showed better perceived health (p<0.05), and women with increased explosive force in standing long jump showed better perceived fitness (p<0.05). Exercising men who had increased knee symptoms had significantly higher body mass index than the other exercising men (p<0.05). The exercise induced injury rate was 19% in men and 6% in women. CONCLUSIONS: Successful completion of the exercise programme, together with the increased physical activity and relatively low injury rate, may have contributed to the participants finding the exercise programme positive and stimulating and believing that their health and fitness had improved. The low rate of musculoskeletal injury suggests that this type of supervised exercise programme is feasible for untrained middle aged people.

Factor structure of the School Well-being Model.

The aim of this study was to confirm empirically the factor structure of the School Well-being Model. In this Model well-being was divided into school conditions, social relationships, means for self-fulfillment and health status. Data for this study were collected by the School Health Promotion Survey in Finland with 40147 respondents from Grades 8 and 9. The 43 variables from the Survey were fitted into the School Well-being Model using confirmatory factor analysis. The Goodness of Fit Index (GFI) for the four-factor model was 0.93 and GFI Adjusted for Degrees of Freedom was 0.93. The correlations between factors varied from 0.30 to 0.78 and internal consistencies (Cronbach's alphas) from 0.62 to 0.84. The categories school conditions and health status had a good variety of variables. However, the social relationships and the means for self-fulfillment categories would have benefited from additional questions. The School Well-being Model can be utilized to construct school well-being profiles both for groups of pupils and for schools as a whole. The school well-being profile could highlight the area or areas in which schools could make improvements in order to promote the well-being of its pupils.

Isoresistive dynamometer measurement of trunk muscle velocity at different angular phases of flexion and extension.

Isoresistive trunk muscle dynamometer is a potentially useful piece of equipment in evaluation of trunk muscle velocity, but to date, studies analysing the possibilities and limitations of such measurements are scarce. The aim of this study was to analyse the trunk muscle velocity in repetitive flexion and extension movements at three different angular phases, using an isoresistive trunk muscle dynamometer, and to assess the reliability of the measurements. The study population consisted of 120 healthy, sedentary men and women who volunteered for the study. The measurements were carried out before and after a 22-week training intervention programme. The results show that the peak velocities of the phases between 15 and 35 degrees in flexion and 20-0 degrees in extension (i.e. the second phases) correlated highly (r=0.99 in flexion and in extension) with the peak velocity of the whole movement ranging from -5 to 55 degrees in flexion and 40 to -20 degrees in extension. Correlations were high, both before and after the intervention. The LISREL model analysis showed high reliability of measurement for the second angular phases (in flexion and extension). According to the model, the correlation between the first and second measurement (with a 22-week training intervention in between) was 0.78 in flexion and 0.81 in extension. In conclusion, the angular phases from 15 to 35 degrees in flexion and from 20 to 0 degrees in extension represent the peak velocity of the whole movement. Negative residual correlations between the first and last angular phases in the LISREL model reflect the way of performing the movement: the faster the start the slower the end, and vice versa.

Radiobiological depth of subcutaneous induration.

The incidence of subcutaneous induration in 23 breast cancer patients with postmastectomy radiotherapy was investigated. The patients were treated with three different radiotherapy schedules 7. 9-9.8 years ago. The incidence was correlated with the biological effective dose (BED) at different depths from the skin surface and a best fit was obtained using an alpha/beta ratio of 2 Gy. The most representative depth at which to assess dose for subcutaneous induration was 2 mm which is near the subcutaneous fat/dermis interface.

Influence of days of the week on reported food, macronutrient and alcohol intake among an adult population in south western Finland.

OBJECTIVE: To study the influence of the days of the week on calculated food and nutrient intake. STUDY DESIGN: Daily variation in food and nutrient intake was studied by using 4-, 5- and 7-d estimated food records, all including Friday, Saturday and Sunday. SUBJECTS AND SETTING: Two groups of untreated hypertensive patients (60 men and 31 women, aged 31-55 y, and 132 men and 94 women, aged 35-54 y) and a random population sample of 131 men and 139 women, aged 35-64 y, all from the City of Turku and three neighbouring municipalities in south western Finland. RESULTS: The intakes of meat and meat products, carbohydrate, alcohol and energy varied significantly across the week in all study groups with increased intakes of meat and meat products on Saturday and Sunday, of carbohydrate and alcohol on Friday and Saturday, and of energy on Friday, Saturday and Sunday. Food and nutrient intakes did not vary consistently with weekdays (Monday to Thursday) with the exception of alcohol intake being lowest on Monday. Macronutrient, alcohol and energy intake data calculated from the 5-d (Monday, Tuesday, Friday, Saturday and Sunday) and from 5 to 7 d converted food records were nearly equal to and correlated highly (r=0.96-0.98) with the data calculated from the 'true' 7 d records. CONCLUSION: The daily variation in food and nutrient intakes should be taken into consideration when food diaries are recorded. 5-d food records including two weekdays (from Monday to Thursday) and Friday, Saturday and Sunday is recommended. SPONSORSHIP: Social Insurance Institution of Finland.

Penetration of electromagnetic fields of an open-ended coaxial probe between 1 MHz and 1 GHz in dielectric skin measurements.

An open-ended coaxial probe is often used for investigating the dielectric properties of biological tissues. The present study indicates that in addition to the probe size, the penetration of the electromagnetic (EM) fields of an open-ended coaxial probe in contact with the skin is dependent on the applied frequency between 1 MHz and 1 GHz. At high frequencies, above 100 MHz, the measured dielectric parameters are functions of the dielectric properties of different cutaneous layers and subcutaneous fat. At lower frequencies, less than 10 MHz, the measurement is mainly dependent on the dielectric properties of superficial structures of the skin. The reason for this is that the probe, the surface of the skin, mainly stratum corneum, and underlying skin form a capacitance where the stratum corneum with low water content lies between the well-conducting dermis and the probe. The situation is equivalent to the frequency-dependent Maxwell-Wagner interfacial polarization. This result is verified by experimental dielectric measurements and with human skin in vivo.

Quantitative assessment of protein content in irradiated human skin.

PURPOSE: Radiation-induced fibrosis is a common late reaction of radiation therapy. Due to a lack of feasible noninvasive techniques to assess this reaction, the long-term development of radiation fibrosis is not well described. In order to develop quantitative means for the purpose, subcutaneous fibrosis of breast cancer patients after postmastectomy radiotherapy was evaluated by clinical scoring and a new technique based on dielectric properties of the skin. METHODS AND MATERIALS: Dielectric properties of biological tissues at radiofrequencies are principally determined by tissue water content. The major skin components are proteins, proteoglycans, and water either free or bound to the surface of proteins and proteoglycans. Since the MR studies have shown that bound water is tightly attached onto the surface of collagen, a dielectric measurement sensitive to bound water could be related to the protein content. Therefore, the dielectric constant of human skin was measured in vivo with an open-ended coaxial probe at electromagnetic (EM) frequencies in the range of delta-dispersion. Since the in vitro experiments with protein-water solutions have indicated that the slope of the dielectric constant vs. the EM frequency is a measure of the protein concentration, a respective slope was determined with irradiated skin of 14 breast cancer patients 2 years after postmastectomy radiotherapy at 63, 100, 300, and 500 MHz. Irradiated skin sites were clinically scored for subcutaneous fibrosis using a scale: none, slight, moderate, or severe fibrosis. RESULTS: A statistically significant correlation was found between the slope and the clinical score of subcutaneous fibrosis at 63, 100, and 300 MHz but not at 500 MHz. The correlation was best at 100 and 300 MHz. CONCLUSIONS: Considerable changes in the dielectric constant of the irradiated skin were found. The correlation between the dielectric constant and clinical score suggests that this novel technique is a potential tool for the follow-up and quantitative assessment of radiation-induced subcutaneous fibrosis.

Variational formulation of open-ended coaxial line in contact with layered biological medium.

An open-ended coaxial probe designed to measure layered biological media is analyzed with a new method. The probe is considered as an electrostatic circuit element whose capacitance is solved using a stationary functional. The fundamental transverse electric and magnetic field (TEM)-mode and the series of evanescent wavemodes in the coaxial cable are used as basis functions. The field outside the probe is solved using a Hankel transform. The capacitance is calculated for homogeneous materials and two-layer structures and the results are compared with values measured with a phantom model. The method can be easily extended for structures with an arbitrary number of layers. A practical approximation for two-layer cases, originally developed to take into account the effect of subcutaneous fat in skin measurements, is presented and its validity for different combinations of dielectric constants and the thickness of the first layer is demonstrated. The static approximation limits the frequency range, but it covers biological measurements up to 500 MHz. The developed method is accurate and easy to adopt in practice.

Observer variation in classifying chest radiographs for small lung opacities and pleural abnormalities in a population sample.

BACKGROUND: The purpose of this study was to assess inter-and intraobserver variation in the radiographic categories of small lung opacities (profusion) and pleural abnormalities classified according to the ILO classification of pneumoconioses with some modifications. METHODS: Chest radiographs derived from a representative adult population sample (n = 7,095) were classified by two radiologists. Observer variation was assessed on the basis of kappa (kappa)-type statistics. RESULTS: The observers agreed on profusion categories in 69% of cases of the total material. Up to 98% of the classifications fell into the same category or deviated by no more than one category. The corresponding kappa (kappa) coefficient was 0.48 (95% CI = 0.46=0.49) and the weighted kappa 0.72. When a selected subsample was reclassified by the observers, the proportions of crude agreement on profusion of small opacities ranged from 42% to 47% (weighted kappa 0.52-0.55). The proportions of agreement on the main pleural abnormalities were 92% or over, and the corresponding kappa coefficients at least 0.73. CONCLUSION: The classification of lung opacities was subject to considerable observer variation, which calls for caution when results from different studies are compared. This variation, however, rarely exceeded one category, and thus appears to be small enough for meaningful comparisons between groups, at least within a single study.

A dielectric method for measuring early and late reactions in irradiated human skin.

BACKGROUND AND PURPOSE: To measure the dielectric constant of irradiated human skin in order to test the feasibility of the dielectric measurements in the quantitation of acute and late radiation reactions. MATERIALS AND METHODS: The dielectric constant of irradiated breast skin was measured at an electromagnetic frequency of 300 MHz in 21 patients during postmastectomy radiotherapy. The measurements were performed with an open-ended coaxial line reflection method. The irradiation technique consisted of an anterior photon field to the lymph nodes and a matched electron field to the chest wall using conventional fractionation of five fractions/week to 50 Gy. Fourteen out of the 21 patients were remeasured 2 years later and the skin was palpated for subcutaneous fibrosis. RESULTS: At 5 weeks the dielectric constant had decreased by 31 and 39% for the investigated skin sites of the photon and electron fields, respectively. There was a statistically significant inverse correlation between the mean dielectric constant and the clinical score of erythema. An unexpected finding was a decrease of the dielectric constant of the contralateral healthy skin during radiotherapy. Two years later a statistically significant positive correlation was found between the dielectric constant at the irradiated skin sites and the clinical score of subcutaneous fibrosis. CONCLUSIONS: Dielectric measurements non-invasively yield quantitative information concerning radiation-induced skin reactions.

Measurement of dielectric properties of subcutaneous fat with open-ended coaxial sensors.

A three-layer model of stratum corneum, epidermis/dermis and subcutaneous fat has been developed for the capacitance of an open-ended coaxial line in contact with human skin. Applying the model, the electrical properties of subcutaneous fat can be calculated from skin dielectric measurements with three probes of different sizes. The three-layer model is based on a variational formula for the capacitance of the coaxial probe. An accurate approximation for the dielectric constant of the multilayer cutaneous structure is presented for the inverse problem of solving the dielectric constants of various layers. The method was tested at 300 MHz with breast cancer patients who often have radiotherapy-induced late alterations in the structure of subcutaneous fat due to the development of subcutaneous fibrosis. Measurements from 206 sites yielded a good agreement between the dielectric constant of subcutaneous fat and the clinical score for subcutaneous fibrosis.

Quality of sleep during economic recession in Finland: a longitudinal cohort study.

To assess the association between the economic recession of the 1990s in Finland and sleep behaviour, a longitudinal study was conducted in an adult Finnish population cohort. Baseline data were obtained by means of reports on sleep behaviour, health-related behaviour, health status, and objective laboratory tests in 1983-1987. The second screening conducted in 1992-1995, i.e. during economic recession, repeated data collection by postal questionnaires. The prevalences of various sleep symptoms including insomnia, daytime tiredness, fatigue, parasomnias and the use of hypnotics remained similar in the same age cohorts during economic recession. Alcohol consumption and snoring increased among the middle-aged (30-49 years), though snoring shows the greatest individual stability among various sleep symptoms. Despite some baseline differences in the sleep/health behaviour frequencies, the changes were independent of gender and socioeconomic class. The prevalences over eight years of insomnia and snoring show fair chronicity, whereas daytime tiredness and fatigue seem to be less chronic. Middle-aged participants who were stably employed at the initial screening but became unemployed during economic recession were studied separately. Prospectively unemployed persons suffered more from insomnia and used more hypnotics than the continuously employed. We conclude that the sleep quality of the general Finnish population has not drastically deteriorated during severe economic recession except among unemployed blue-collar workers.

What does the multiple sleep latency test measure in a community sample?

Multiple sleep latency test (MSLT)-defined daytime sleepiness and its relationships with nocturnal and daytime psychophysiological activation were investigated in a random community sample of 77 subjects aged 35-55 years. The correlation structure between all study variables was explained by a simple model of daytime sleepiness. The model suggested that indicators of psychophysiological arousal (psychological distress, nocturnal motor activity and serum thyrotropin level) and daytime reported tiredness, body mass index (BMI) and age were related significantly and independently to MSLT-defined daytime sleepiness. The arousal theory of insomnia and poor sleep in relation to MSLT behavior is discussed and the need of a multivariate approach is emphasized in MSLT studies.

An empirical investigation of the 'Biopsychosocial Disease Consequence model': psychological impairment, disability and handicap in chronic pain patients.

The purpose of this study is to emphasize the meaningfulness of a global, functional rather than a narrow medical view in the efficacy evaluation of chronic pain treatment. Therefore, the 'Biopsychosocial Disease Consequence (BPSDC) model' to assess function more globally than before, is presented in this article. The model is based on two theories: (1) the biopsychosocial approach and (2) WHO's classification of impairments, disabilities and handicaps. In addition to the presentation of the conceptual model, the development of the hypothetical criteria and assessment models for psychological impairments, disabilities and handicaps, and the validity testing of the psychological assessment axis are described. Within each of the three classes, i.e. psychological impairments, disabilities and handicaps, the results supported the independence of the hypothetical criteria from each other. On the other hand, results suggested that some changes to the hypothetical assessment models for some of the criteria might be valuable. It was concluded that although the most adequate psychological assessment models for function, found in this study, can be considered as robust and recommendable as one set of tools for functional assessment, the main aim of this article is to encourage multidisciplinary team efforts to develop and systematize the assessment procedures of function in patients suffering from chronic diseases.

Nocturnal motor activity in a community sample.

The relationships between nocturnal motor activity and daytime psychophysiological activation were investigated in a random community sample of 199 subjects aged 35-55 years. Nocturnal motor activity was recorded with the static charge sensitive bed (SCSB, Bio-Matt). The association of nocturnal motor activity with demographic features, health status, laboratory blood values, afternoon electrodermal activity (EDA) and psychological distress was studied. A model for nocturnal motor activity was constructed and statistically analyzed. The analysis revealed that psychological distress, breathing disturbance, plasma glucose level and sympathetic activity were related significantly and independently to nocturnal motor activity. Their relations and the associations of sex, age, body mass index (BMI), sleep latency and health status with nocturnal motor activity were discussed in the context of the arousal theory of poor sleep.

Couple therapy improves mental well-being in chronic low back pain patients. A controlled, five year follow-up study.

Fifty-six chronic low back pain (CLBP) patients participated in a controlled, prospective 5-yr follow-up study evaluating the long-term effects of five-session couple therapy. Twenty-eight patients were included both in the treatment group and in the control group. Outcome measures were self-reported psychological distress, marital satisfaction, health locus of control, pain and disability as well as clinical examinations. The reliability of the outcome measures was statistically analysed and found acceptable. At the 5-yr follow-up assessments, psychological distress was found to be decreased in the treatment group and increased in controls. The difference between the groups was significant. No difference was found in the other self-reported or clinical outcome measures. We conclude that couple therapy has a prolonged beneficial effect on the mental well-being of CLBP patients.

A controlled study of couple therapy in chronic low back pain patients. No improvement of disability.

Family-oriented approaches and consequent conjoint marital sessions have been widely accepted as ingredients of comprehensive treatment and rehabilitation of chronic pain patients. However, no controlled trials have been conducted to confirm the effectiveness of couple therapy in these patients. We examined 63 chronic low back pain (CLBP) patients identified in primary health care centres. They were randomly allocated to a couple therapy group (n = 33) and to a control group without couple therapy (n = 30). The therapy consisted of five monthly sessions and was attended by two family therapists. All patients attended an initial examination and a 12-month follow-up examination. Effects on self-reported pain, disability, and some clinical measures, as well as on the use of medical services were evaluated. The study groups did not differ significantly in any of the outcome measures. Hence, we conclude that couple therapy has no significant effect on disability in CLBP patients.

The relation between cycling time to exhaustion and anaerobic threshold.

This study investigated whether the anaerobic threshold (AnT) could be used to predict prolonged work capacity measured as cycling time to exhaustion (= endurance time) and which factors, in addition to relative exercise intensity, could explain variation in endurance time. Theoretical exercise intensities corresponding to certain endurance times were also calculated. The hyperbolic and exponential functions between cycling time and relative work rate (WR[%]), as well as between cycling time and relative oxygen uptake (VO2[%]) were fitted to the pooled data (n = 45) of 17 subjects. The WR(%) and VO2(%) were expressed as a percentage of the subject's own AnT- and maximum-values. At WR corresponding to AnT (i.e., 70% of WRmax) an average subject could cycle 60 min according to both AnT- or maximum-related exponential function. When prediction was done for an endurance time of 4 h, the AnT-related exponential function gave 2.9%-units (= 11 W or approximately 0.15 O2 l.min-1) lower intensity level (51% of WRmax) than the maximum-related function (54% of WRmax). The WR(%) alone explained 54% and 70% of the variation in endurance time of the AnT-related and maximum-related exponential functions, respectively. Muscle fibre composition and initial blood lactate or relative muscle glycogen depletion (change in muscle glycogen as percentage) increased significantly the explanatory power of these models. The differences between the observed and expected exercise times correlated with blood lactate accumulation (r = -0.42; p less than 0.01), muscle fibre composition (r = 0.33; p less than 0.05) and relative muscle glycogen depletion (r = 0.67; p less than 0.01). It was concluded that the capacity for prolonged work measured as cycling time to exhaustion can be estimated by AnT-related power output, and that the exponential function model is the most suitable. Prediction power of the model can be improved by multiple regressions including muscle fibre composition, initial blood lactate level and relative muscle glycogen depletion.