Work-related physical fatigue and fatigue management - ICMM
Work-related physical fatigue and fatigue management - ICMM
Work-related physical fatigue and fatigue management - ICMM
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<strong>Work</strong>-<strong>related</strong> <strong>physical</strong> <strong>fatigue</strong> <strong>and</strong> <strong>fatigue</strong><br />
<strong>management</strong><br />
Schu Schutte<br />
Human Factors Research Group<br />
CSIR Centre for Mining Innovation
Presentation framework<br />
• Is <strong>physical</strong> <strong>fatigue</strong> a problem<br />
in mining?<br />
• How hard do mineworkers<br />
work?<br />
• Interventions to manage<br />
<strong>physical</strong> <strong>fatigue</strong>.<br />
Slide 2<br />
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Factors contributing to <strong>physical</strong> <strong>fatigue</strong><br />
• Mining is often classified as one of the<br />
most <strong>physical</strong>ly dem<strong>and</strong>ing occupations<br />
(heavy <strong>physical</strong> workloads).<br />
• Despite the introduction of technology<br />
hard <strong>physical</strong> work is still performed.<br />
• Physical conditions in workplaces<br />
(temperature, noise, whole-body <strong>and</strong><br />
segmental vibration).<br />
Slide 3<br />
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Why concerned about <strong>physical</strong> <strong>fatigue</strong>?<br />
• Observations that miners complain<br />
about „tiredness‟, high levels of<br />
<strong>physical</strong> exertion <strong>and</strong> „<strong>fatigue</strong>‟.<br />
• Changing demographics of mining<br />
population (aging population, female<br />
mineworkers).<br />
• Physical work requirements should<br />
meet abilities <strong>and</strong> limitations of<br />
mineworkers in order to minimize<br />
<strong>physical</strong> <strong>fatigue</strong> <strong>and</strong> create a safe<br />
work environment.<br />
Slide 4<br />
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Heat stress<br />
VRT<br />
60 - 80º C<br />
Slide 5<br />
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Physically dem<strong>and</strong>ing work<br />
Slide 6<br />
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<strong>Work</strong>place design: Narrow reef mining<br />
Slide 7<br />
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Awkward body posture/whole body<br />
vibration<br />
Slide 8<br />
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Diversity of SA mining population<br />
• No longer all male workforce<br />
• 10% of workforce female by end-<br />
2009.<br />
• Heat intolerance: (♀ 35%; ♂ 5%).<br />
• Aging mining population.<br />
• Not so healthy - chronic disease risk<br />
profile:<br />
- 16 % HIV+<br />
- 40 % high blood pressure<br />
- 30 % overweight<br />
Slide 9<br />
© CSIR 2011 ww.csir.co.za
Slide 10 © CSIR 2011 ww.csir.co.za
Women vs Men in terms of <strong>physical</strong> abilities<br />
• On average lower<br />
aerobic capacities<br />
than men.<br />
• Fatigue: for the same<br />
<strong>physical</strong> task ♀ work<br />
closer to aerobic<br />
capacity than ♂; more<br />
likely to become<br />
<strong>fatigue</strong>d.<br />
• Functional strength<br />
lower than males<br />
Slide 11<br />
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How hard do miners work?<br />
• Limited real-time information (usually estimates).<br />
• Why is this information important?<br />
• Use information to identify occupations with high <strong>physical</strong><br />
<strong>fatigue</strong> risk.<br />
• Identify activities that needs interventions to reduce risk of<br />
<strong>physical</strong> <strong>fatigue</strong>.<br />
Slide 12<br />
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Metabolic rates for various<br />
underground work categories<br />
Slide 13<br />
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<strong>Work</strong> intensity<br />
• Metabolic rate on average<br />
of moderately high<br />
intensity (130 -180 W/m 2)<br />
• Hard work (metabolic rate<br />
181 – 240 W/m 2 )<br />
primarily associated with<br />
“production” occupations<br />
• Very hard work (> 240<br />
W/m 2 ) generally of short<br />
duration<br />
Slide 14<br />
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<strong>Work</strong> Capacity of New Recruits in the SA Mining Industry<br />
100<br />
75<br />
Male (n = 64 000)<br />
%<br />
50<br />
43<br />
39<br />
36<br />
Female (n = 19 572)<br />
25<br />
8 7<br />
18<br />
10<br />
15<br />
20<br />
4<br />
0<br />
Sedentary Light Moderate Heavy Very Heavy<br />
Job Intensity Categories<br />
Slide 15<br />
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Assessment of physiological strain<br />
• Monitor heart rate <strong>and</strong> body core temperature over full<br />
shift.<br />
• Estimate VO2 max, determine physiological strain <strong>and</strong><br />
obtain heart rate profile.<br />
• In order to prevent <strong>physical</strong> <strong>fatigue</strong> the 40% level of VO2<br />
max (HR = 110 beats /min) is recommended when tasks<br />
involve dynamic muscle work.<br />
Slide 16<br />
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Physiological monitoring<br />
Lap top<br />
Data recorder<br />
Data cable<br />
Sensors<br />
Heart rate<br />
Slide 17<br />
Temperature<br />
© CSIR 2011 ww.csir.co.za
Physiological Responses: U/G Winch Operator<br />
-1<br />
HR (bt.min )<br />
160<br />
150<br />
140<br />
130<br />
120<br />
110<br />
100<br />
90<br />
Operate winch (08:00 – 11:30)<br />
In cage (04:42)<br />
Operating winch (11:50 -13:00)<br />
Transport pack support (13:05)<br />
HR<br />
Temp<br />
Chairlift<br />
(15:00)<br />
42.0<br />
41.0<br />
40.0<br />
39.0<br />
38.0<br />
37.0<br />
Temperature (°C)<br />
80<br />
70<br />
60<br />
50<br />
Walking up raise (07:30)<br />
Pulling rope from c/gulley<br />
to face (07:45)<br />
Change rope from face to<br />
c/gulley (11:40)<br />
Install pack<br />
(13:35)<br />
36.0<br />
35.0<br />
34.0<br />
Time (hh:mm:ss)<br />
Slide 18<br />
© CSIR 2011 ww.csir.co.za
Physiological Responses: U/G Winch Operator<br />
160<br />
150<br />
140<br />
Transport pack support (13:05)<br />
HR<br />
Temp<br />
Chairlift<br />
(15:00)<br />
42.0<br />
41.0<br />
-1<br />
HR (bt.min )<br />
130<br />
120<br />
110<br />
100<br />
90<br />
Operate winch (08:00 – 11:30)<br />
In cage (04:42)<br />
Operating winch (11:50 -13:00)<br />
40.0<br />
39.0<br />
38.0<br />
37.0<br />
Temperature (°C)<br />
80<br />
70<br />
60<br />
50<br />
Walking up raise (07:30)<br />
Pulling rope from c/gulley<br />
to face (07:45)<br />
Change rope from face to<br />
c/gulley (11:40)<br />
Install pack<br />
(13:35)<br />
36.0<br />
35.0<br />
34.0<br />
Time (hh:mm:ss)<br />
Slide 19<br />
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Females vs Males<br />
Heart rate<br />
(beats/min)<br />
Core body<br />
temperature<br />
(◦C)<br />
% of HR<br />
> 110 beats/min<br />
Female 121,9 ± 25,1* 37,68 ± 0,37ºC* 49%*<br />
Male 86,1 ± 22,4 37,24 ± 0,44ºC 14%<br />
* Significant difference from males<br />
Slide 20<br />
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Physiological responses: Physiological Data Mining Subject 11 (MT) Team Member<br />
160<br />
140<br />
120<br />
Moving rocks<br />
with shovel<br />
(07:37)<br />
Moving rocks with<br />
shovel (09:55)<br />
Transport<br />
packs <strong>and</strong> build<br />
permanent<br />
support (10:35)<br />
HR<br />
Temp<br />
42<br />
41<br />
40<br />
HR(bt.min -1 )<br />
100<br />
80<br />
60<br />
In cage<br />
(05:14)<br />
Sitting (05:57)<br />
Walk up raise<br />
(13:50)<br />
39<br />
38<br />
37<br />
Temperature (°C)<br />
40<br />
Changing <strong>and</strong><br />
walking (06:47)<br />
Walk down<br />
raise (07:10)<br />
Carry <strong>and</strong><br />
installing<br />
temporary<br />
support (09:30)<br />
36<br />
20<br />
35<br />
0<br />
34<br />
05:02:01<br />
Slide 21<br />
05:32:01<br />
06:02:01<br />
06:32:01<br />
07:02:01<br />
07:32:01<br />
08:02:01<br />
08:32:01<br />
09:02:01<br />
09:32:01<br />
10:02:01<br />
10:32:01<br />
11:02:01<br />
11:32:01<br />
12:02:01<br />
12:32:01<br />
© CSIR 2011 ww.csir.co.za<br />
Time (hh:mm:ss)<br />
13:02:01<br />
13:32:01<br />
14:02:01<br />
14:32:01<br />
15:02:01<br />
15:32:01
Haul truck driver: Physiological responses during night shift<br />
Physiological Responses Subject 14<br />
1 )<br />
Heart Rate (bt.min-<br />
200<br />
190<br />
180<br />
170<br />
160<br />
150<br />
140<br />
130<br />
120<br />
110<br />
Climbing onto<br />
truck (22.55)<br />
Resting head on<br />
steering wheel<br />
while idling (23:48)<br />
Peak following initail drive to<br />
shovel. Marks the start of<br />
hour long period of inactivity<br />
(23.50)<br />
Resumed driving<br />
Sleeping on activities<br />
steerinig (01:10)<br />
wheel (00:11)<br />
Dumping followed<br />
by driving (02:31)<br />
Operator<br />
falling asleep<br />
at wheel<br />
while waiting<br />
(03:22)<br />
Resumation of<br />
driving<br />
activities<br />
(03:35)<br />
Stopped to take<br />
a break (03:41)<br />
Asleep on<br />
steering wheel<br />
(04:21) <strong>and</strong><br />
(04:51)<br />
Temp<br />
HR<br />
Drinking water,<br />
more awake as it<br />
is now light<br />
(05:04)<br />
40.0<br />
39.5<br />
39.0<br />
38.5<br />
38.0<br />
37.5<br />
37.0<br />
Temperature (◦C)<br />
100<br />
90<br />
36.5<br />
80<br />
36.0<br />
70<br />
60<br />
35.5<br />
50<br />
35.0<br />
22:31:06<br />
23:01:06<br />
23:31:06<br />
00:01:06<br />
00:31:06<br />
01:01:06<br />
01:31:06<br />
02:01:06<br />
02:31:06<br />
03:01:06<br />
03:31:06<br />
04:01:06<br />
04:31:06<br />
05:01:06<br />
05:31:06<br />
Time (hh:mm:ss)<br />
Slide 22<br />
© CSIR 2011 ww.csir.co.za
Interventions to manage <strong>physical</strong> <strong>fatigue</strong><br />
• Ergonomics design of workplaces <strong>and</strong> tasks based on the<br />
abilities <strong>and</strong> limitations of workers should be the primary<br />
strategy.<br />
• When technical <strong>and</strong> <strong>physical</strong> constraints in the mining<br />
environment hinder the implementation of this strategy,<br />
the selection of workers on the basis of <strong>physical</strong> abilities<br />
becomes necessary.<br />
• Both the above should form part of a comprehensive<br />
<strong>fatigue</strong> <strong>management</strong> programme.<br />
Slide 23<br />
© CSIR 2011 ww.csir.co.za
Thank you
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