task design_29th august 2011

8/4/2019 Task Design_29th August 2011

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Task Design


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Poor workstation design can lead to:

lower back injury;

the development or aggravation of RSIs(Repetitive Strain Injuries)2;

circulatory problems in the legs.


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When considering a workstation:

1. If it feels right, it probably is right. If it feels

uncomfortable, there is probably something

wrong with the workstation design, NOT the

worker!

2. The more you use it, the closer it should be

to the worker.


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A workers reach


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There are also a number of sensible provisions that

managers can take to improve the workstation. These

include:

identify the tools that are used the most frequently; place these most frequently used tools in the usual work area so that they

can be reached without stretching;

tools such as nippers and scissors which are used frequently should be

attached to the sewing machine or bench by cord this minimises the

time spent searching. On no account should these tools be hung around

the workers neck as is a common practice. The reason for this is that

many of the machine parts are unguarded and any cord could get caught

in the gear.

items such as pins can be kept in one place by using magnets attached to

the case of a machine or a pin cushion. Other small accessories such as

buttons, hooks, etc., can be kept in small, clearly labelled boxes within

easy reach;

where possible, containers should be provided for material inputs and

outputs make sure the containers are not too deep and consider if they

can be mobile for faster transport to the next operation.


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Sitting and Chair Design

Lower back problems are on the increase as moreworkers sit at their workstations all day. Often, workersare provided with simple benches with no backrest. Awell-designed chair is essential one that is adjustable

for individual workers, for the height of the worktableand task, and that provides full lower back support. Thechair should allow workers to lean forward andbackwards easily. The worker should have adequate legroom under the worktable so that he/she can change the

position of the legs easily. The feet should be flat on thefloor or the worker should be provided with a footrestthis will eliminate pressure on the thighs and knees.


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Correct Seating


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Chair


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Advantages of Standing Workstation

1.Reach is greater in standing than in sitting.

2. Body weight can be used to exert forces.

3. Standing workers require less leg room than

seated workers.4. Lumbar disc pressures are lower.

5. It can be maintained with little muscular activity

and requires no attention.6. Trunk muscle power is twice as large in standing

than in semi-standing or sitting.


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Standing Workstation


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Hand Tools and Controls

Hand tools should be designed according to ergonomicrequirements that means:-

choose tools that allow workers to use larger muscles in theshoulders, arms legs, rather than the smaller muscles in thewrists and fingers;

do not use tools with spaces where fingers and skin can getcaught ;

choose tools that do not require the worker to bend thewrist, stoop, stretch or twist;

choose tools with handles that are long enough to fit thewhole hand;

where possible, tools should be appropriate for right andleft-handed workers.


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Hand Tools & Control

The tool should fit comfortably into your hand. If

the grip size is too large or too small it will be

uncomfortable and will increase the risk of

injury. Tools should not have sharp edges, createcontact stresses in your hand, or vibrate.


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Hand Tools


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Tools that can catch fingers


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Keep repetitive motions to a minimum

Our workstations or tasks can often be redesigned to

reduce the number of repetitive motions that must be

performed. Using a power-driven screwdriver or tools

with a ratchet device can reduce the number of twistingmotions with the arm. Some tasks can be automated or

redesigned to eliminate repetitive movements and

musculoskeletal injuries.


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Bending of Wrists


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Bending of Wrists


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Easy Reach


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Lifting

Lift with the legs and keep a straight back. Lift in easy stages.


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Lifting

Stand close to the object and keep your feet apart to maintain your balance.


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Lifting


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Lift with both hands if possible. Make sure that you grip the load with your

palms and not your fingers. Dont change your grip while carrying. Dont let

the load obstruct your view get help and make sure that the route is clear

before you start moving.


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If you are lifting to the side, place your feet in a walking position with one

foot pointing slightly in the direction of the lift. Lift the object and then shift

the weight of the body on to the foot in the turning direction


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If you have to lift a load above shoulder level,

place your feet in a walking position and raise

the load in easy stages.


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If the load is too heavy (Prakas 124 specifies 25 kg for women and 50 kg

maximum load for direct lifting), get help. Lift together at the same time

and speed. Carry objects close to your body and spread the weight evenly in

both hands.


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Job Design


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Cutting Dept.

LOADING THE SPREADING MACHINE

Loading the spreading machine involves lifting a bolt of

fabric from the floor into a spreader, or on to a spreadingtable if the fabric is spread by hand.

COMMON PROBLEMS

Loading by hand. Bolts of fabric lifted by hand are very

heavy and create a substantial risk of low back injury.


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SPREADING THE FABRIC

COMMON PROBLEMS

Spreading by hand. Long reaches are required to cut

across the width of the fabric each time a layer iscompleted or flaws are removed from the fabric.

Spreading with a fixed holder that holds the bolt in

place at the end of the spreading table. A long reach isrequired to cut across the width of the fabric.

Manual spreading. Using a spreading machine that theoperator pushes back and forth on the spreading table


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Automated spreading.

Operators either ride on a platform or walk beside theautomatic spreader as it moves along the table.

Operators often have to smooth the fabric while it is

being spread.

The table is often too low and operators have to bend

their backs while smoothing. This is a risky posture whenmaintained for extended periods of time.


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Cutting

COMMON PROBLEMS

Band saw. Excessive reaching caused by

improper workstation height.

Inability to get close to the blade.

Poor waste disposal.


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Cutting

Die cutters. Workstations that are too high

require the operator to work with raised arms.

Workstations that are too low require them to

bend down.

Controls often require poor thumb postures.


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Cutting

Electric saws. Excessive reaching with shoulders

and back.

Poor wrist postures.

Hand or arm vibration and contact pressure on

the hand when stapling the pattern to the

fabric.

task design_29th august 2011

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