ERGONOMICS

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Bureau of Workers CompPA Training for Health & Safety

(PATHS)

Ergonomics is the science of fitting jobs to people. Ergonomics encompasses the body of knowledge about physical abilities and limitations, as well as other human characteristics, that are relevant to job design.

Ergonomic design is the application of this body of knowledge to the design of the workplace (work tasks, equipment, environment) for safe and efficient use by workers.

Good ergonomic design makes the most efficient use of worker capabilities while ensuring that job demands do not exceed those capabilities.

What is Ergonomics?

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Ergonomic Hazard Identification

Do not ignore signs, symptoms and hazards!

Make recommendations for control of hazards to your supervisor.

Ergonomic Lifting Device

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Musculoskeletal Disorders

Musculoskeletal disorders, or MSDs, are injuries or illnesses to soft body tissue such as:

MusclesNervesTendons

LigamentsJoints

CartilageSpinal Discs

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Joints, Muscles, Tendons, etc.

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Musculoskeletal Disorders

MSDs do not include injuries caused by slips, trips, falls or other similar accidents.

MSDs can differ in severity from mild, periodic symptoms to severe, chronic and debilitating conditions.

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MSDs – Signs & Symptoms

•Aching

•Burning

•Cramping

•Loss of Color

•Numbness

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MSDs – Signs & Symptoms

•Pain

•Swelling

•Stiffness

•Tingling

•Weakness

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MSDs-Carpal Tunnel Syndrome (CTS)

• Carpal Tunnel – a tunnel

in the wrist through which the median nerve and nine digital flexor tendons pass.

• Formed by the wrist bones and a dense trans-carpal ligament.

• Continued and repetitive pressure on the median nerve in the carpal tunnel can cause CTS.

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MSDs-How CTS Develops

1. Swelling or thickening of the carpal tendon starts.

2. The tunnel begins to close.

3. This exerts pressure on the median nerve.

4. Feel pain/discomfort.

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MSDs-Prevention of CTS

• If you do the same tasks with your hands over and over, try not to bend, extend or twist your hands for long periods.

• Don’t work with your arms too close or too far from your body.

• Don’t rest your wrists on hard surfaces for long periods.

• Switch hands during work tasks, if possible.

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MSDs-Prevention of CTS

• Take regular breaks from repeated hand movements to give your hands and wrists time to rest.

• Don’t sit or stand in the same position all day.• Ensure your chair is adjusted so that your forearms

are level with your keyboard and you don’t have to flex your wrists to type.

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MSDs-Common Causes of Back Injuries

• Heavy lifting from above the shoulders

• Heavy lifting from below the knees

• Twisting while lifting/carrying

• Bending over at the waist

• Carrying objects to one side

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MSDs-Protecting your Back

Lifting

• Avoid bending at the waist. • Squat down with your back

straight and knees bent. • Grasp the object. • Bring it close to your body.• Slowly rise. • Let your thigh muscles do

the lifting.

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MSDs-Protecting your Back

Standing

• Shift your weight slightly. • Use proper footwear with cushioned insoles. • Avoid high heels. • Proper posture when standing: shoulders not rolled forward, stomach area is

pulled in, small of the back is straight, hips not tilted

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Footwear

Which one gives the best support if you do a lot of walking/standing?

This pair for sure!

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MSDs-Protecting your Back

Sitting

• Use an adjustable chair with lower back support.

• Keep knees in line with the hip joints or slightly lower.

• Sit with the lower back firmly against the chair back support.

• Shift elevation of the legs during prolonged sitting.

• Avoid crossing your legs.

Any ergonomic issues?

If prolonged sitting, back will hurt without support.

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MSDs-Protecting your Back

Lying down • Lie on your side with your knees slightly bent. • Use a pillow to elevate your head, keeping it in

line with your back. • If you sleep on your back, place a pillow under

your knees to relieve lower back stress and promote proper alignment.

Awkward position-could cause ergonomic issues if in the position for

extended period

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MSDs-Joint Disorders

• Joints include many structures, such as tendons, muscles, nerves and bones.

• Inflammation may be caused by joint damage or repetitive, heavy use.

• With inadequate repair, cartilage thinning may lead to osteoarthritis.

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MSDs-Joint Disorders

• Repetitive or prolonged stair- or ladder-climbing, kneeling or squatting, standing, carrying heavy loads and jumping are work tasks that may be associated with lower-extremity joint loading.

• Mechanical stresses associated with certain tasks can cause degenerative joint disease.

• Degenerative joint disease can occur even after relatively low loads on joints if the forces are applied recklessly and repetitively.

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MSD Risk Factors- Awkward Postures

Two Types: Static = nonmoving Dynamic = body in motion

Stress increases if any weight is added by tools or other objects.

Factors include:▪ Time▪ Repetition▪ Body condition▪ Health▪ Range of motion

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MSD Risk Factors-Avoid:

• Bending wrists • Twisting at the waist

• Rolling shoulders

• Leaning forward

• Bending at the waist

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MSD Risk Factors-Avoid:

• Winged elbows

• Overreaching

• Stepping backward

• Locking your knees

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MSD Risk Factors

Force & Exertion = Forceful exertions place higher loads on the muscles, tendons, ligaments and joints.

Factors:•Weight of load or tool

•Bulkiness of load or tool•Posture

•Speed of movement

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MSD Risk Factors

Lifting •Place heavier material above the knees and below shoulder height. •Use team lifting. •Use mechanical devices such as tool supports, platforms lifts, barrel lifts, air lifts and hoists.

Moving •Reduce required force by using carts, trolleys, pallet jacks, conveyors and tracked lifts.

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MSD Risk Factors

Reduce Force and Exertion by Reducing:

• Weight of the object• Weight of the container• Load in the container• Size of the container

• Quantity per container

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MSD Risk Factors – Gripping

FACTORS:• Weight

• Slipperiness

• Vibration

• Grip type

• Surface and grip area shape

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MSD Risk Factors – Pressure

Hazards = Damage to Nerves and Blood Vessels

• External Compression – sharp edges concentrate forces on a small area of the anatomy resulting in high, localized pressure.• Internal Compression – nerves, vessels and other soft tissues may be internally compressed under

conditions of: High-force exertions Awkward postures Static postures High velocity or acceleration of movement Swelling of injured tissue

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MSD Risk Factors – Pressure

Tools and Work Practice Hazards:

• Tools with short handles (such as pliers and paint scrapers)

• Leaning the side of the elbow on a hard surface

• Carrying heavy loads on the shoulder

• Long periods of kneeling

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Ergonomic Tools

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MSD Risk Factors – Cold Temperatures

• Cold environments compromise muscle efficiency.

• Possible vascular and neurological damage.

• Workers with cold-desensitized fingers may grasp loads with more force than necessary thereby exposing muscles, soft tissues and joints to increased force.

• Alcohol, nicotine, caffeine and some medication increases MSD risks from cold temperatures.

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MSD Risk Factors – Noise

Effects:

• Increased muscle tension

• Quicker onset of fatigue

• Mental stress

• Reduced concentration

• Diverted attention

• Slower recovery time32PPT-010-02

MSD Risk Factors - Lighting

Hazards of too much or not enough light:

• Awkward postures

• Muscle fatigue

• Eye strain

• Mental fatigue

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Life Factors - Exercise

Proper exercise means:• Improved health• Stronger body• Improved endurance• Reduced stress• Better range of

motion

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Life Factors – Effects of Smoking

• Restricts blood vessels

• Carbon monoxide in blood

• Longer recovery from injury

• Increased injuries from vibration

• Increased injuries from cold

• Poor general health

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Life Factors-Medication

Medication has the potential to increase the risk of MSDs if it:

• Lowers or raises normal blood pressure

• Changes sense of balance

• Masks pain• Relaxes muscles• Affects blood circulation• Affects eyesight

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Ergonomic Controls-Engineering

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Ergonomic Controls-Engineering

Engineering controls:

• Are the preferred method for controlling hazards

• Make physical changes to tasks• Act on the source of the hazard• Control employee exposure• Do not require “self-protective” action

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Ergonomic Workstations

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Ergonomic Controls-Administrative

Administrative controls = procedures and

methods that significantly reduce daily exposure to WMSD hazards by altering the way in which work is performed.

Examples:• Employee Rotation

• Job task enlargement• Adjustment of work place• Redesign of work methods

• Alternative tasks• Rest breaks

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Ergonomic Controls - Work Practice Controls

Work Practice Controls:

• Are behavior-based controls that change the manner in which a job is performed

• Procedures for safe and proper work that are understood and followed by managers, supervisors and employees

• Examples of work practice controls for WMSD hazards include:

Safe work techniques and procedures Conditioning period for new or reassigned employees Training in the recognition of ergonomic hazards Training in work techniques that reduce MSD hazard

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Sitting Posture

• Use a straight chair with support for your lower spinal curve. You can use a small cushion or rolled up towel behind your back to maintain the proper curve .

• Check the seat’s height. • Adjust your seat so that your knees are slightly

lower than your hips. • If the seat’s height is not adjustable, use a

footrest if necessary.• Keep your feet flat; avoid crossing your legs.• Keep your ankles and elbows at right angles.

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Sitting Posture

• Sit close to your desk so you don’t have to bend forward.

• If you do bend, bend from your hips.• Position your work or chair so you can look

forward rather than down.• Use a document holder or move your computer

screen so the top of it is at eye level.• Shift your position frequently to prevent strain. • Take a break or do stretching exercises

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Ergonomic Chair

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Prevent, Prevent, Prevent!

• The bottom line: prevent accidents and injuries from occurring!

• Ensuring your workstation is ergonomically designed is one method to prevent injuries.

• All employees need to have a basic understanding of ergonomics and should report any ergonomic hazards to their supervisor immediately.

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Exercises – Knee Kiss

Pull one leg to your chest, grasp with both hands and hold for a count of five.

Repeat with the opposite leg.

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Exercises - Windmill

Place your feet apart on the floor.

Bend over and touch your right hand to your left foot, with your left arm up.

Repeat with opposite arm.

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Exercises – Back Relaxer

Bend down between your knees for as long as you can.

Return to upright position, straighten and relax.

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Exercises – Pectoral Stretch

Grasp your hands behind your neck and press your elbows back as far as you can.

Return to starting position, then drop your arms and relax.

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Exercises – Middle/Upper Back Stretch

Raise your right arm and grasp it below the elbow with your left hand.

Gently pull your right elbow toward your left shoulder as you feel the stretch.

Hold for five seconds.

Repeat with left arm.

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Exercises – Side Stretch

Interlace your fingers and lift your arms over your head, keeping your elbows straight.

Press your arms backward as far as you can.

Slowly lean to the left and then to the right until you can feel the stretching.

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Exercises – Finger Stretch

With palms down, spread your fingers apart as far as you can.

Hold for the count of five.

Relax and then repeat.

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Exercises – Shoulder Roll

Slowly roll your shoulders forward five times in a circular motion using your full range of motion.

Then roll your shoulders backward five times with the same circular motion.

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Review

• Repetitive motion tasks can lead to Musculo-Skeletal Disorders (MSDs).

• Maintain correct posture while sitting/standing/walking.

• Stretch to “limber up” muscles before and after work.

• Take regular breaks.

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Review

• Exercise regularly.

• Ensure your workstation is set up to be ergonomically correct.

• Ensure lighting in your work area is adequate.

• Report ergonomic hazards or symptoms to your supervisor.

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Questions

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