A psychophysical approach to determine the frequency and duration of work-rest schedules for manual handling operations.

The primary objectives of this study were: (1) to test whether rest allowances could be ascertained using a psychophysical methodology; and (2) to examine the effects of gender and frequency of handling on work-rest schedules. Two experiments were conducted, each experimental session at 4h. A psychophysical methodology was used where the subject was given control of the working and resting durations. The results of the study indicated that: (1) the total working time decreased and the total resting time decreased with an increase in the frequency of handling; (2) high frequency tasks required more frequent rest allowances; (3) for the same manual handling tasks, women needed more frequent and longer allowances than men; (4) experience with the manual handling of material reduced the variability collected from the psychophysical methodology. The application of the psychophysical methodology in industry is discussed.

[1]  E Hultman,et al.  Cardiorespiratory and metabolic costs of continuous and intermittent exercise in man , 1973, The Journal of physiology.

[2]  W Rohmert,et al.  Problems of determination of rest allowances Part 2: determining rest allowances in different human tasks. , 1973, Applied ergonomics.

[3]  Etienne Grandjean,et al.  Fitting the Task to the Man: A Textbook of Occupational Ergonomics , 1988 .

[4]  E H CHRISTENSEN,et al.  The influence of rest pauses on mechanical efficiency. , 1960, Acta physiologica Scandinavica.

[5]  G. Borg.  Physical performance and perceived exertion , 1962 .

[6]  P E Di Prampero,et al.  Energy utilization in intermittent exercise of supramaximal intensity. , 1969, Journal of applied physiology.

[7]  E H CHRISTENSEN,et al.  Intermittent muscular work. , 1960, Acta physiologica Scandinavica.

[8]  E H CHRISTENSEN,et al.  Myohemoglobin as an oxygen-store in man. , 1960, Acta physiologica Scandinavica.

[9]  S S Asfour,et al.  Physiologic responses to static, dynamic and combined work. , 1986, American Industrial Hygiene Association journal.

[10]  Stephan A. Konz,et al.  Work Design: Industrial Ergonomics , 1983 .

[11]  George Kanawaty,et al.  Introduction to work study , 1992 .

[12]  E H CHRISTENSEN,et al.  Intermittent and continuous running. (A further contribution to the physiology of intermittent work.) , 1960, Acta physiologica Scandinavica.

[13]  A M Genaidy.  A training programme to improve human physical capability for manual handling jobs. , 1991, Ergonomics.

[14]  O. Wigertz,et al.  Physiological Correlates of Perceived Exertion in Continuous and Intermittent Exercise with the Same Average Power Output , 1972, European journal of clinical investigation.

[15]  P CERRETELLI,et al.  BALANCE AND KINETICS OF ANAEROBIC ENERGY RELEASE DURING STRENUOUS EXERCISE IN MAN. , 1964, Journal of applied physiology.

[16]  Bengt Saltin,et al.  Intermittent Exercise: its Physiology and some Practical Applications , 1976 .

[17]  W Rohmert,et al.  Problems in determining rest allowances Part 1: use of modern methods to evaluate stress and strain in static muscular work. , 1973, Applied ergonomics.

[18]  Stover H. Snook,et al.  The Ergonomics Society The Society's Lecture 1978. THE DESIGN OF MANUAL HANDLING TASKS , 1978 .