Recognition of Work-Related Musculoskeletal, Nerve Disease
What is Ergonomics?Ergonomics is the science of fitting the job to the worker.
Ergonomics refers to a work environment designed to maximize safety and increase productivity.
What is Ergonomics Gone Bad?
When there is a mismatch between the physical requirements of the job and the physical capacity of the worker, work-related musculoskeletal disorders (MSD) may result.
Repetitive motion injuryCumulative trauma disorderMusculoskeletal disorder (MSD)Repetitive stress injurySprains, strains, tears
Musculoskeletal DisordersInjuries or disorders of:musclestendonsligamentsnerves (compression or entrapment)spinal discsjoints and cartilage
Muscle painJoint painSwellingNumbnessRestricted motionLow back painSigns and Symptoms
Musculoskeletal Disorders Upper Extremities
Upper Back Lower Back Feet and Legs Hands Arms Shoulder Neck
Benefits of Good ErgonomicsDecreased injury riskIncreased productivityDecreased mistakes/rework
Decreased lost work daysDecreased turnoverImproved moral
Risk Factors for Ergonomic Hazards
- Repetitive Motion/CycleSame repetitive taskUse of same muscle groupsShort cycle (~
Awkward PostureOverhead ReachTwisting
Heavy lifting Forceful exertions, pulling, pushing, twisting
Contact StressUsing the hand or knee as a hammer
VibrationWhole body vibratione.g.., Crane operators, truck driversSegmental vibrationPneumatic tools, grinders
Risk Factors Also Depend On:Duration of stressAmount of recovery timeTemperatureDecrease blood flow to muscles (cold)
And a Higher Risk Occurs When:Risk factors are multiple
Controlling Ergonomic Hazards
Control Hierarchy Engineering controlsPhysical changes Administrative controlsEmployee rotationChange of paceJob enlargementWork practice controlsUtilization of better procedures, posturePersonal Protective equipment
Manual Material Handling and Back Protection
Acute vs. Chronic StressorsAcute: Where the injury arises from a single identifiable event - when transient loads exceed internal tolerances.
Chronic:Where repeated trauma (albeit incapable of injury in isolation), after sufficient duration, reduces internal capacity resulting in eventual injury.Microtrauma
Back InjuryMuscle LigamentVertebraeDiscs
Ergonomic Risk Factors for BacksAwkward postureSittingStatic, bent posturesFatigue/agingWhole body vibration
Ergonomic Risk Factors for BacksHandling excessive weight/forceLoad sizeFrequency of liftingGrip considerationPoor physical condition
Kinds of Back InjuriesBack strains-When weak or tense muscles are stretched beyond their limit
Back sprains-A partial or complete tear of a back ligament
Herniated discs-Resulting when stress, strain or gradual deterioration on a disc causes it to stick out between the vertebrae
Ruptured discs-When the wall of a disc breaks open.
Upper Extremities Work-Related MSDs
EffectsPainInflammationSwellingNumbnessDecrease in range of motionLoss of functionCycle of injury
UECTD Risk Factors Awkward Wrist Postures
Tendon DisordersTendonitis:Fibers can become inflamed, fray or tear apart, tendons can thicken, become bumpy and irregular and without sufficient recovery time become permanently weakened
Tendon Disorders Epicondylitis
Lateral epicondylitis - tennis elbow (inflammation of tendon fibers - outside of elbow) Source: American Society for Surgery of the Hand Medial epicondylitis or golfers elbow (inside)
Tendon DisordersRotator cuff tendonitisSource:NIH, Medline Plus Repetitive overhead work Elevated elbows
TendonsStenosing Tenosynovitis (progressive restriction of the synovial sheath)De Quervains disease (thumb tendons)
TendonsTenosynovitis (injury of the synovial sheath)
Source: Cleveland Clinic Ganglionic cyst (swelling of the synovial fluid) Trigger finger (stenosing tenosynovitis crepitans)
Nerve DisordersInjuries or disorders of the median nerve:Carpal tunnel syndrome (compression of he median nerve as it passes through the carpal tunnel)Pronator syndrome (compression of median nerve as it passes between the two heads of the pronator teres muscle)
Cubital Tunnel Pain/Numbness www.medicalmultimediagroup.com
Bursitis Shoulder Bursitis Bursa irritated and thickens with overuse
Neurovascular Disorders Thoracic outlet syndrome- Caused by compression of the neurovascular bundle from repetitive activities overhead or with the arm pulled down towards the back
Neck DisordersTension or ache in the neck (local muscle tightness/spasm)Numbness in the arms or hands (nerve impingement)
Lower Extremities Work-Related MSDs
Knee DisordersChondromalacia: degeneration (softening) of the cartilage on the posterior aspect of the kneecap Bursitis of the knee
Lower leg disordersShin splints: involve damage to one of two groups of muscles along the shin bone (caused by standing for a long time or repetitive stress to the lower leg)
Foot DisordersPlantar fasciitis (inflammation of the plantar fascia--the tissue that forms the arch of the foot) Tarsal tunnel syndrome (entrapment of the tibial nerve)
Work Tool DesignReduce forces
Work Tool DesignUse power grip
Work Tool DesignUse optimal grasp span
Work Environmental Concerns
(Heat Stress,Energy Expenditure and Vibration)
Heat DisordersHeat strokeHeat exhaustionHeat cramp
Heat collapseHeat rashHeat fatigue
Heat Stress OperationsIron and steel foundriesNonferrous foundriesBrickfiring and ceramic plantsGlass product facilitiesRubber product factories
Factors Affecting Susceptibility to HeatAgeWeightDegree of physical fitness and acclimatizationMetabolism
Environmental FactorsAir movementHumidityConductionRadiant heat exchange
Engineering ControlsVentilationAir coolingFansShielding Insulation
Types of VibrationWhole BodyHand-Arm (HAVS)
SummaryWhen there is a mismatch between the physical requirements of the job and the physical capacity of the worker, work-related musculoskeletal disorders (MSD) may result.Risk Factors for ergonomic hazards:Repetitive motion cycleAwkward postureForceContact stressVibrationUpper extremities work-related MSDsLower extremities work-related MSDs
This presentation is designed to assist trainers conducting OSHA, 10-hour General Industry outreach training for workers. Since workers are the target audience, this presentation emphasizes hazard identification, avoidance, and control not standards. No attempt has been made to treat the topic exhaustively. It is essential that trainers tailor their presentations to the needs and understanding of their audience.
This presentation is not a substitute for any of the provisions of the Occupational Safety and Health Act of 1970 or for any standards issued by the U.S. Department of Labor. Mention of trade names, commercial products, or organizations does not imply endorsement by the U.S. Department of Labor.
Ergonomics is an engineering discipline that addresses the effect work environments and tasks have on the employee. Ergonomics involves workstation set-up and design, body posture, prevention of computer-related injuries and more.
Clues that indicate ergonomic problems may also suggest the scope of the effort required to correct them. For example, signs implicating multiple jobs in various departments and involving a large percentage of the workforce would indicate the need for a full-scale, company-wide program. Alternatively, signs that the suspected problems are confined to isolated tasks and relatively few workers may suggest starting with a more limited, focused activity. Often workers are given little choice and are forced to adapt to poorly designed work conditions, which can lead to serious injury to the hands, wrists, joints, back or other parts of the body. In particular, injuries can result from: 1. repeated use over time of vibrating tools and equipment, such as a jackhammer; 2. tools and tasks which require twisting hand or joint movements, such as the work many mechanics perform; 3. applying force in an awkward position; 4. applying excessive pressure on parts of the hand, back, wrists or joints; 5. working with the arms outstretched or over the head; 6. working with a bent back; and 7. lifting or pushing heavy loads.
Physical injuries caused by performing unsafe manual handling tasks. Includes injuries such as muscle sprains and strains; injuries to muscles, ligaments and discs in the back; injuries to nerves, ligaments and tendons in the hands, wrists, arms, shoulders, neck or legs; and abdominal hernias and long-term pain. Signs and Symptoms:Numbness or a burning sensation in the hand Reduced grip strength in the hand Swelling or stiffness in the joints Pain in wrists, forearms, elbows, neck, or back followed by discomfort Reduced range of motion in the shoulder, neck, or back Dry, itchy, or sore eyes Blurred or double vision Aching or tingling Cramping Loss of color in affected regions Weakness Tension stress headaches and related ailments
The different types of Musculoskeletal Disorders are as follows:Repetitive Stain Injury Carpal Tunnel Syndrome Other Ergonomic Problems
Saving Time by Using Good Ergon