Manual material
handling
Manual material handling includes
any tasks which require a person to
lift, lower, push, pull, hold or carry
any object or material.
Manual
material
handling
Why is manual handling a
problem?
• Across the world, many
workplaces are experiencing an
increase in the number of
Musculoskeletal Injury (MSI).
• MSIs account for a big portion of
term claim costs.
• Approximately 70% of all MSIs are
injuries to the back and shoulders.
Manual
material
handling
o
A
musculoskeletal injury (MSI)
is an injury or
disorder of the muscles, tendons, ligaments,
joints, nerves, blood vessels or related soft
tissue arising from exposure to risk factors
such as awkward postures, repetitive motions
and forceful exertions.
Manual
material
handling:
Stages of
cumulative
MSIs:
Stage 1
Mild discomfort, present while working, but disappears
when not working. Does not affect work performance or
daily living tasks. Completely reversible.
Stage 2
Pain is present while working and continues when not
working. Begins to affect daily living tasks. Employees
sometimes take non-prescription pain medications.
Completely reversible.
Stage 3
Pain is present all the time. Employees seek medical
attention. May not be able to complete simple daily tasks.
May not be completely reversible to reach full recovery.
Manual tasks risk factors
•
Research has identified specific risk factors related to hazardous manual
tasks that
play a significant role
in the development of musculoskeletal
injuries.
•
By
preventing or minimizing
the exposure to these risk factors, the risk of
injury can be reduced
.
•
The seven manual tasks risk factors are:
•
awkward postures
•
forceful and sustained exertions
•
repetition
•
Static and sustained postures
•
vibration
•
Contact stress.
o
The term awkward postures refers to any posture where
the body parts are away from their comfortable, neutral
position (
e.g. a bent back, a bent wrist or arms raised above
the head
).
o
Awkward postures result in stretching or shortening of the
connective and nervous tissues. As a result, the functional
capacity of muscles can be reduced and the tissues are at
greater risk of injury.
o
Awkward postures are
not always harmful
—it is only
when they are repeated frequently or performed for a
long time.
o
Forceful exertions place high loads on soft body
tissue such as muscles, tendons, ligaments, joints
and discs to match the required task workload..
o
Muscles fatigue with increased exertion and need
more time to recover.
o
If soft tissue does not have time to recover, injury
is likely to develop over a period of time.
o
If the exertions are forceful enough, body
tissues may be damaged immediately.
o
Repetition means making the same type of
movements over and over (e.g. laying bricks).
o
The work cycle is the time taken to perform the
task once without interruption (e.g. the time to
lay one brick).
o
Tasks involving short cycle times (less than 30
seconds) and performed for more than one hour,
are considered to be a risk because the same
muscles and other soft tissues are being used
continuously.
o
This contributes to their fatigue and risk of injury.
o
Tasks involving longer cycle times and shorter
task duration will have a lower risk of injury.
Static and Sustained
Postures
•
A fixed position, with minimal
movement of the particular body part
•
Promote fatigue & discomfort due to
lack blood circulation
•
Likely to cause irritation, inflammation
or strains
•
Worst in combination with poor
postures, contact stress & long
duration
Whole Body Vibration
Exposure to whole body vibration occurs when the body or parts of the body come in contact with a
vibrating surface, such as the seat, pedal or floor of heavy vehicles or machinery.
Whole body vibration exposure has been shown to be a strong contributor to lower back injuries
Hand/Arm Vibration.
Exposure to hand/arm vibration occurs when working
with air- operated, pneumatic, electric, or
petrol-powered tools.
Exposure to hand/arm vibration primarily damages
blood vessels and nerve tissue, typically of the hand and
fingers.
Prolonged exposure can eventually result in a disease
known as Raynaud’s syndrome or Vibration White Finger.
Vibration
Contact Stress
• Contact between body soft tissue and hard/sharp objects (gripping, holding, prolonged standing)
• It creates pressure over a small area of the body (wrist, forearm) that can inhibit (slow-down) blood flow
• Can restrict the movement of the tendon which will then require greater effort and could result in inflammation of tendon and surrounding tissues
• Worse in combination with prolonged duration, repeated exposure & high pressure
• Certain areas are more susceptible because nerves, tendons and blood vessels are close to the skin and underling bone such as the wrists, forearm, elbows, knees and feet
Ways to minimize risk
Know what the manual
tasks risk factors
Apply the Design
Controls
Apply the
Administrative
Controls
o Work area design which includes the work area and the
environment where the job is based. Poor design may cause forceful exertions and awkward and static postures.
o Tool design which includes the design of the tool being used. Poor design may cause vibration, forceful exertions, awkward and static postures.
o Load handling design which includes the characteristics of the load and the method of handling. Poor design may cause forceful exertions and awkward and static postures.
o Work organisation which includes issues such as the length of the shift, how often the task is performed, the number of workers assigned to the task and the pace of work. Poor design may cause repetition and duration
o Involve redesigning the task, workplace or tools to eliminate or reduce the risk.
o Include elimination, substitution and engineering controls:
Elimination
Eliminate the problem task completely (e.g. automate a complete job process or aspects of a particular task).
Substitution
• Replace heavy items with lighter, smaller and/or easier to handle items (e.g. items with handles). This may involve discussions with manufacturers, suppliers and/or delivery providers.
• Substitute a cotton mop-head with one made of microfibre.
• Use of polypropylene wheelbarrow instead of steel.
Apply the Design Controls:
o Include elimination, substitution and engineering controls:
Engineering Controls
•Provide work benches or store items between knee and shoulder height to reduce awkward postures and increased force. Reduce any kind of bending, twisting or reaching movements!
•Use mechanical lifting aids such as cranes, forklifts, pallet jacks and trolleys to move items.
•Cover tool handles with dampening materials to absorb vibration. Use dampening materials in floors and around vibrating machinery to reduce worker exposure to vibration.
•Repackaging loads: if carrying a heavy load, break the load into smaller quantities
•Warm up before working as well as take breaks to prevent muscle strain and fatigue.
•Rearranging workplace/redesign hardware
Apply the Design Controls:
Workstation design and setup
Ergonomically designed tools
Ergonomically designed equipment
Load weight reduction
Source: OSHA (International Labor Organization)
o Administrative controls focus on implementing policies and procedures such as Standard Operating Procedures (SOPs) and typically include:
•maintenance programs to ensure plant, tools and equipment are maintained on a regular basis
•work organization, such as job rotation, to ensure adequate staff numbers are available to meet work demands and reduce shift length
•task-specific training to ensure workers are trained in their specific work, such as using tools and mechanical aids
•use of personal protective equipment (PPE), such as anti-vibration gloves, to reduce the exposure to anti-vibration, or shock absorbent shoes for work on hard (concrete) floors; and
•return to work programs appropriate to individual fitness levels after extended periods of leave.
o Controlling exposures to occupational hazards is the fundamental method of protecting workers.
o Traditionally, a hierarchy of controls has been used as a means of determining how to implement
feasible and effective control solutions.
o The idea behind this hierarchy is that the control methods at the top of graphic are potentially more effective and protective than those at the bottom.
o Following this hierarchy normally leads to the
implementation of inherently safer systems, where the risk of illness or injury has been substantially reduced.
Hierarchy of controls
MOST EFFECTIVE
Elimination and Substitution
Most effective at reducing hazards, but most difficult to
implement in an existing process – may require major changes
Engineering Controls
• Designed to remove the hazard at the source
• The initial cost of engineering controls can be higher, but over the longer term, operating costs are frequently lower
Administrative Controls and PPE
• Frequently used with existing processes where hazards are not particularly well controlled
• Inexpensive to establish but, over the long term, can be very costly to sustain
• less effective than other measures, requiring significant effort by the affected workers
The requirements to safely manual handling involves the knowledge of
correctly knowing how to lift a heavy object, pull, push and carry a heavy
object to prevent injuries.
SAFE MANUAL HANDLING REQUIREMENTS AND MANUAL HANDLING
TECHNIQUES
Load Pushing and Pulling Capabilities:
Approximately 20% of overexertion injuries have been associated with pushing and pulling acts. One of the leading causes of non- vehicle related deaths in industry is slipping and/or falling.
• Safe lifting techniques should be stressed by all workplaces but are commonly overlooked. Most people just want to finish the job quickly, even if that means moving heavy objects in unsafe ways.
• In doing so, workers can become injured and have to miss work for extended periods of time.
NIOSH lifting
equation
NIOSH lifting equation
NIOSH Lifting Equation is a tool used by occupational health and safety professionals to assess the manual material
handling risks associated with lifting and lowering tasks in the workplace.
This equation considers job task variables to determine safe lifting practices and guidelines.
The equation is:
RWL = LC x HM x VM x DM x AM x FM x CM
where LC is the load constant (23 kg) and other factors in the equation are:
RWL: Recommended Weight Limit
HM: The horizontal distance from hands to the center of the body (defined as mid-point between ankles). VM: The vertical distance between the hands (holding the load in the starting position) and the floor.
DM: The vertical distance the load is lifted, measured from starting point to end point. FM: The time between lifts and the overall duration of lifts during a work-shift.
AM: The angle of asymmetry to the lift. The degree required to twist the body during the lifting task. CM: The quality of the grasp on the load as defined by 'good', 'fair' or 'poor'.
