ASSESSMENT OF PHYSICAL WORK CAPACITY AMONG CHILDREN WITH DOWN SYNDROME

The purpose of this investigation was to compare physical work capacity (PWC), peak oxygen uptake (peak VO2), maximal pulmonary ventilation (VEmax), maximal heart rate (HRmax), and maximal blood lactate concentration (LAmax) for wheelchair ergometer (WERG) and arm crank ergometer (ACE) exercise. For this, wheelchair-dependent (n = 6) and able-bodied (n = 10) subjects completed a progressive intensity, discontinuous test for each mode of exercise. Each test was terminated by physical exhaustion and/or an inability to maintain a flywheel velocity of 180 m.min-1. Relatively high correlation coefficients were found between values obtained during the two modes of ergometry for PWC, peak VO2, VEmax, and HRmax. WERG exercise was found to elicit a significantly (P less than 0.05) lower PWC (by 36%), HRmax (by 7%), and LAmax (by 26%) than ACE exercise. Peak VO2 and VEmax, however, were similar for both exercise modes. These data suggest that either exercise mode may be used for fitness testing and training of people who cannot use their legs and that arm cranking may be a superior method to propel wheelchairs.

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Lifting Physical Work Capacity as a Function of Frequency

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/154193128703101207 ◽

1987 ◽

Vol 31 (12) ◽

pp. 1331-1335

Author(s):

Jeffrey E. Fernandez ◽

Robert J. Marley ◽

Nancy B. Stubbs

Keyword(s):

Laboratory Experiment ◽

Work Capacity ◽

Task Design ◽

Physical Work ◽

Physical Work Capacity ◽

Frequency Range ◽

Lifting Technique ◽

Male Subjects

A laboratory experiment using 15 male subjects was conducted to document lifting physical work capacity over the frequency range of 2 to 12 lifts per minute and to compare these values to bicycling physical work capacity. Results indicate that bicycling PWC is significantly higher than lifting PWC at the 0.05 level. A variation in lifting PWC as a function of frequency was observed. This could be attributed to lifting technique. Task design should, therefore, not only consider lifting PWC but also the frequency of lift.

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The impact of heat on human physical work capacity; Part III: the impact of solar radiation varies with air temperature, humidity, and clothing coverage.

10.1101/2021.07.01.449782 ◽

2021 ◽

Author(s):

Josh Foster ◽

James W Smallcombe ◽

Simon G Hodder ◽

Andreas D Flouris ◽

Lars Nybo ◽

...

Keyword(s):

Solar Radiation ◽

Air Temperature ◽

Work Productivity ◽

Work Capacity ◽

Physical Work ◽

Physical Work Capacity ◽

Adult Males ◽

Cumulative Energy ◽

Heat Effects ◽

The Impact

It is well-known that heat impacts human labour/physical work capacity (PWC), but systematic evaluations of solar radiation (SOLAR) effects and the interaction with air temperature and humidity levels and clothing are lacking, as most lab-studies are conducted in semi-nude subjects without radiation or only in a single climatic condition. Due to the high relevance of SOLAR in various occupations, this study quantified how SOLAR interacts with clothing and other primary environmental factors (air temperature/humidity) of importance to determine PWC in the heat. The data allowed the development of a SOLAR correction factor for predicting PWC in major outdoor industries. Fourteen young adult males (7 wearing a standardised work coverall (0.9 Clo), 7 with shorts and trainers (0.3 Clo) walked for 1-hour at a fixed heart rate of 130 b∙min-1, in seven combinations of air temperature (25 to 45 Celsius) and relative humidity (20 or 80%), with and without SOLAR (800 W/m2 from solar lamps). Cumulative energy expenditure in the heat, relative to the work achieved in a cool reference condition, was used to determine PWC%. Skin temperature was the primary determinant of PWC in the heat. In dry climates with exposed skin (0.3 Clo), SOLAR caused PWC to decrease exponentially with rising air temperature, whereas work coveralls (0.9 Clo) negated this effect. In humid conditions, the SOLAR-induced reduction in PWC was consistent and linear across all levels of air temperature, and clothing conditions. WBGT and UTCI based prediction equations of PWC represented SOLAR correctly. For heat indices not intrinsically accounting for SOLAR, correction factors are provided enabling forecasting of heat effects on work productivity.

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