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Biomedical subjects

J Rutenfranz

Publications and source records attributed to J Rutenfranz.

18 recordsLinked to original sources
PubMed1978

[The effect of an on the job training program -- stairclimbing -- on the physical working capacity of employees (author's transl)].

Following medical screening and physical fitness testing (W170) 52 voltuntary employees in a 31-story administration building were formed into matched pairs and randomly allocated into intervention (stairclimbing) and control (lift) groups. The intervention group was asked to climb at least 25 floors/workday or 125 floors/week. the control group was asked to use only the lift. The intervention time was 10 weeks. The physiological measurements were made before and after the intervention. The number of stairs climbed was recorded daily in a diary. The heart rate was recorded continuously over one workday before and during the interventions. The average quantity of training in the final intervention group (n = 19) was 29.9 floors/workday or 36,790 kpm/week and in the control group 4.6 and 5980 correspondingly. The average training frequency was 4.3 in intervention and 1.4 climbs/workday in the control group. The average number of continuous floors used during climbing was 7.0 in intervention and 3.4 in control group. The average number of minutes on heart rate level of 130-159 beats/min during one workday was 7.8 in intervention and 1.6 in control group. The W170 (W/kg) increased 17.8% and the predicted VO2max (ml/min/kg) 15.1% in intervention group. The difference between the intervention group and the control group was significant (p less than 0.01). It was concluded, that stairclimbing is a suitable on the job physical activity program for middle-aged, untrained men.

Employment↗
PubMed1978

[Studies on the influence of various mathematical formulations on the determination of the proportion of fat in relation to bodyweight by means of skin fold measurements (author's transl)].

The paper reports on investigations on the influence of various mathematical formulations on the determination of the proportion of fat in relation to body-weight by means of skin fold measurements. For this purpose, the various equations derived from Archimedes' law, as well as the densities of various body fractions as determined by different authors, are discussed. This is followed by a discussion of the deliberations on the methods to be employed for estimating the density of the body by means of skin fold measurements. The various formulations differ from each other mainly by the location and number of measuring points. It was shown by means of comparative studies that for children aged between 9 and 16, independent of their sex, it will be sufficient to employ two skin folds (triceps and scapula). The existence of a very close correlation between the measured data of these points of measurement was found when using different calipers and the relevant conversion factors. In this manner it becomes possible to use a nomogram which has already been determined by Parízková and which was converted into a matrix for easier calculation. The determination of the relative proportion of fat'via skin fold measurements cannot replace the determination of individual body density by weighing under water. However, in mass examinations it is very well suited for differentiating between various groups of children (e.g. overweight, underweight, trained, and untrained) in respect of their relative proportion of fat.

Adipose Tissue↗
PubMed1978

[Shift work and biological rhythms (author's transl)].

In highly industrialised countries shift work has become inevitable for technological, economic and social reasons. At the present time approximately 20% of the workforce are engaged in shift work, which partly includes night and weekend work. As a result of this form of work, diseases and disorders manifest themselves in shift workers which--combined with an individual predisposition or with certain situational factors--arise partly from disturbance of sleep on the day after night work, partly from difficulties in adapting biological function to the phase-shift of work and sleep. The resulting biological and organisational problems with respect to the practicabilities of shift work are discussed in the light of studies on experimental shift work.

Body Temperature↗
PubMed1977

[Experiences with a cardiorecorder system for continuous 24-hour registration of heart rate].

Studies regarding to the continuous registration of the heart frequency by a transportable instrument, which can store the data of the heart frequency per minute up to 24h, are presented. It is a tape recorder the speed of which is geared down. Thus a normal tape cassette C 60 is sufficient for a registration of the heart frequency during 2 X 24h. The R-wave of the ECG is registered on the first channel of the tape as a biological signal. Moreover every minute an impulse of a clock is recorded on the second channel of the tape. With help of a second instrument the play back procedure for the 24-h-recording can be performed in about 15 min. The signals of both channels of the tape are transformed in digital rectangle impulses by an installed impulse-converter. The serial impulses are counted per minute with help of the time-mark by an interface in a counter. These data are at disposal in BCD-code. They can be passed on the following peripherals: digital printer, computer, pen-recorder and so on. A parallel standardized recording of the physical activity observed by the subject or by an experimenter allows a statistical evaluation and comparison of the physical activity with the corresponding heart frequency data. Some examples of the aread of occupational health, epidemiology and exercise physiology are discussed.

Electrocardiography↗
PubMed1977

Biomedical and psychosocial aspects of shift work. A review.

A survey of the different types of shift-work systems in use, and the incidence of shift work in different industries and countries, is followed by a discussion of (a) the effects of shift work on health and (b) the physiological problems raised by the phase-shifting of the circadian cycle in night workers. Summaries of the existing knowledge of the effects of shift work on performance efficiency, accidents, and family and social life are then given, and a set of criteria for designing optimal shift systems is proposed. Next, the questions of selection for shift work and the provision of health services for shiftworkers are discussed. Finally, the need for further research on the problems of shift work is explained, and suggestions are offered on the lines such research should follow.

Accidents↗
PubMed1976

Physical performance capacity of children in Norway. Part IV. The rate of growth in maximal aerobic power and the influence of improved physical education of children in a rural community - population parameters in a rural community.

During a period of 4 years the annual increase of the physical performance of 31 boys and 34 girls was examined in a longitudinal study. In spite of the expected mean increase of the physical performance unsystematic annual variations of the increase of the maximal oxygen uptake related to body weight were observed. These variations can only be explained by the variations of the daily physical activity. The fact that in the longitudinal study a clear better performance over the years was observed than in a cross sectional study which was performed in the first year of the longitudinal study confirms this tendency. This can partly be explained by the improvement of the possibilities for physical activities in the community since the begin of the longitudinal study.

Adipose Tissue↗
PubMed1975

[Study of the circadian variation of different circulatory and respiratory functions at submaximal and maximal ergometer work (author's transl)].

The maximal aerobic power of six highly trained young cyclist, mean age 16.3 years and mean VO2max 4.9 l/min, was directly measured at intervals of 4 hrs. A Latin square design was used for the test order. At submaximal work of O2-consumption 2.4 to 4.4 l/min no circadian variation of any single function was found. However, at maximal work load the differences between the maxima and minima values were 12.4% for maximal work output (W max), 7.8% for expiratory minute volume (V Emax), 5.7% for maximal aerobic power (VO2max) and 3.4% for maximal heart rate (H Rmax). All the functions--with the exception of VO2max-had their minima at 0300 hrs; the minima of VO2max was reached already at 2300 hours. The maxima-values of V Emax and VO2max were measured at 1500 hrs, of W max and H Rmax at 0700 and of H Rrest at 1900 hrs correspondingly. A one-tailed test showed significant differences between the maxima and minima values of all variables (P less than 0.05). The results suggest a decreased cardiopulmonary working capacity at night. However, this impairment is only of practical importance if the work will be done near the limit of endurance capacity. Besides it will suggest, that the indirect methods for assessing the cardiopulmonary capacity based on VO2max and W170 are not useful at nighttime, because the presuppositions for these methods are limited of the time of day.

Adolescent↗
PubMed1975

[Determination of lean body mass by skin fold measurements (author's transl)].

Skin folds were measured on 12 different body sites of 32 boys, aged 9--12, by using the calipers of Best, Lange, Harpenden and Holtain successively. We compared the measurements of the biceps, triceps, scapula, suprailiaca, abdominal and thigh skin folds. The results depended on body sites as well as on the type of caliper used. Therefore, conversion is recommendable only when absolute values of body fat must be taken into consideration, as when investigating population parameters in terms of functional performance capacity. Moreover conversion is necessary when using those nomograms which are built up mainly by measurements with an unusual caliper. Conversions must be omitted when comparing data by means of rank-correlations.

Abdomen↗