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Biomedical subjects

M M Ayoub

Publications and source records attributed to M M Ayoub.

At least 37 records · Page 2Linked to original sources
PubMed1983

Perceived exertion of physical effort for various manual handling tasks.

Ten trained male students between 18 and 28 years of age participated in a study, designed to determine the relationship between perceived exertion and physiological costs of exertion during various manual lifting and lowering tasks. Perceived exertion was defined as one's subjective rating of the intensity of work being performed. Five subjects performed lifting tasks and another five performed lowering tasks. Weight of load lifted or lowered (6.8, 13.6, 20.5 kg), frequency of lift or lower (3, 6, 9 times/min), height of lift or lower (floor to 76 cm, 76 to 127 cm, floor to 127 cm), box width (38, 66 cm), box length (38, 66 cm) and angle of twist of the body (0 degree, 90 degrees) were the independent variables studied. Heart rate, oxygen consumption, and ratings of perceived exertion (RPE) were the response measures. RPE was found almost linearly related to heart rate and oxygen consumption when lifting or lowering loads. For lifting tasks, the coefficient of correlation between RPE and heart rate was 0.673. In the case of lowering tasks, this coefficient was 0.604. When oxygen consumption was considered, the corresponding coefficients for lifting and lowering were 0.734 and 0.619, respectively. The correlation of RPE with the physiological response variables indicates that the severity of manual materials handling tasks in industry can be evaluated quickly and inexpensively by using perceived exertion ratings (RPE).

Adolescent↗
PubMed1981

Effect of task variables and their interactions in lifting and lowering loads.

An experiment was designed to study the effect of several task variables on the metabolic energy expenditure and heart rate of individuals performing lifting and lowering tasks. The task variables studied were: load of lift (lower), frequency of lift (lower), height of lift (lower), presence of absence of handles, container height, container width (in the frontal plane) and container length (in the sagittal plane). Four male subjects participated in the experiment. Their oxygen uptake and heart rate were monitored. Various strength measurements were made on the subjects before their participation in the study and after the study was over. The data were analyzed separately for lifting and lowering, using the analysis of variance. Container height did not affect the metabolic energy expenditure or heart rate of the subjects for lifting or lowering activities. Presence or absence of handles did not cause a significant change (alpha greater than or equal to .10) in the physiological responses for lowering tasks. All other task variable effects, however, were significant (alpha less than or equal to .01). A strong first and second order interaction was observed among the task variables. There was a significant increase in the strength (alpha less than or equal to .025) of subjects after performing manual materials handling activities for about seven weeks. A dimensional sensitivity analysis indicated that unit change in box width was more expensive than unit change in box length up to .56 m (22 inches). Beyond this, unit change in box length became critical. The weight/bulk ratio of the object did not affect the physiological responses.

Adolescent↗
PubMed1979

Predicint lifting capacity.

As science and technology become more sophisticated and with the rapid computation capabilities of the modern computer available, it becomes both possible and economically feasible to scientifically study man and his interaction with his working environment. It is now possible for a person seeking employment to expect and obtain a position which will not be unnecessarily hazardous to his immediate health or have detrimental effects over the long run. Manual materials handling is the contributor of over 400,000 back injuries suffered in the U.S. each year. This research is directed at determining the appropriate operator variables to measure for predicting the permissible weight of lift for three ranges of lift: floor to knuckle height, knuckle height to shoulder height, and shoulder height to reach height. A modified psychophysical procedure was used during which the subjects were instructed to adjust the weight in a tote box to the maximum weight they could lift repetitively without excessive strain or fatique. The task consisted of lifting loads under different conditions of task variables, namely, height of lift, frequency of lift, and load size. Industrial workers as well as students of both sexes were used as subjects. Based on the data obtained, the lifting capacity of the worker was determined for the different ranges of lift. In addition, predictive models were developed based on the operator variables and the task variables investigated.

Accident Prevention↗
PubMed1977

Lifting capacity of workers.

In order to establish a valid criteria on which to establish lifting guidelines, lifting capacity determination must be made. This has been attempted using several approaches mainly psychophysical, physiological, and biomechanical methodologies. Although the data obtained from these approaches yield information about lifting capacity, some conflict in these data can be found. The purpose of this paper is to discuss the three different approaches, the data obtained from these approaches, and some data on the lifting capacity for males and females in the industrial workforce. In addition, the conflicts in these data are also presented.

Biomechanical Phenomena↗
PubMed1976

Work scheduling under normal and prolonged-vibration environments.

This paper summarizes the research conducted to study human performance and recovery under prolonged, whole-body, vertical vibration. The results showed that performance under vibratory environment is inferior to that under normal environment. Interaction between work-rest schedules and the vibratory environment was detected. Parameters affecting selection of optimum work-rest schedules are discussed.

Attention↗
PubMed1976

Assessment of the physical work capacity of institutionalized mentally retarded males.

Educable and trainable mentally retarded males (N=37) were examined for physical work capacity. Analysis of results indicated that the physical work capacity of the test population was 20 to 30% below that cited in the literature for nonretarded subjects of similar age and sex. Evidence also suggested that developmental and maintenance programs of physical fitness were required in order for mentally retarded persons to qualify for and maintain employment on most of the manual occupational tasks cited.

Adolescent↗