Deeper and more rapid breathing, greater oxygen intake
Increased heart rate and blood flow
Increased release of glucose from liver
More heat generated by muscular activity
More heat lost through skin
from increased bloodflow and
sweating
Metabolic speed increase
Acumilation of lactic acid
in muscles as work
continues
Therefore, there are direct chemical, physical and electrical measures of dynamic workload, though
practical difficulties in measuring these
Borg's scale
A subjective scale wich asks the subject to rate their
perception of the work they are undertaking
Scale developed to have scientific correlation and meaning
while still remaining subjective
Scale of percieved intensity has ratio property, meaning that zero
is a relevant score
Scale of percieved intensity
RPE - rating of percieved exertion
Measure of Dynamic work
Perception of static work is different to dynamic
Noticed in the form of fatigue, pain or discomfort
Caused by build up of lactic acid locally witin muscles
Electromyography (EMG)
Direct measurement of muscle tension for static work
Info obtained from
electrodes attached to skin
Most reliable method of
measuring static work
Difficult to apply to deep laying muscles
and requires expertise to apply properly
Records changes in the electrical potential of
a muscle when it contracts
NIOSH Equations
An equation which takes many factors into account to assess
appropriate lifting weights and postures
Used to reduce work related lifting injuries and lower lifting loads
Takes into account biomechanical, physiological
and psychphysical factors
Revised methods were better at identifying high and
medium risk situations, but missed low risk ones
Posture Assessment
It is important to assess posture as it
affects forces acting on the body as well
as forces the body is able to exert
Assessed using recorded videos, measurements lumbaar
motion monitors ans sensors
RULA and REBA
An easily conducted and quick assessment of 4 key
areas of posture position and work with instant feedback
Considers four key risk factors for WRULDs: Awkward/extreme
posture of the upper limbs, neck, back and legs ; need for static
work ; forces required; need for repetition Identifies body parts
at risk