MUSCULOSKELETAL MUSCULOSKELETAL DISORDERSDISORDERS

•Often occur when the physical demands of work cause wear and tear

•Involve soft tissues such as muscles, tendons, ligaments, joints, nerves, blood vessels

They are cumulative (occur over time and not a result of a single incident):

Work-related musculoskeletal Work-related musculoskeletal disordersdisorders

Work-related musculoskeletal Work-related musculoskeletal disordersdisorders

•Broken bones•Cuts•Slips•Falls•Trips•Motor vehicle accidents•Being struck by or caught with objects

They are not acute injuries such as:

Hazards Hazards Work operations are necessary in many industries such as welding, construction, manufacturing, maintenance, etc.

Welding has several hazardous conditions for women and men in these jobs.

WMSD HazardsWMSD HazardsWorked-related musculoskeletal disorders (WMSD) hazards such as: awkward body postures, lifting heavy equipment or materials, static postures for prolonged periods, awkward postures of the wrist, etc.

Common disordersCommon disordersBack injuriesShoulder pain/loss of range of motionTendinitis/BursitisReduced muscle strengthWhite fingerCarpal tunnel syndromeKnee joint diseases

By Nature of Injury

Sprains account for more than 1/3 of the compensable claims among welders in the State of Washington.

Some of those could be caused by hazardous WMSD exposures.

WA State-funded compensable claims WA State-funded compensable claims 1994-20041994-2004Welders, Cutters, SolderersWelders, Cutters, Solderers

Hearing loss11%

I ll-Def Symptoms

9%

Neural5%

Other13%

Sprains32%

Contussion/Cut/

Scratches 16%

Fracture/Dislocation

14%

WMDS hazards most common in WMDS hazards most common in workwork

Rigorous manual precision requirements◦High degree of uniformity

Awkward and static postures◦Difficult work position

Heavy lifting, difficult material handling◦Heavy objects, heavy welding equipment

Repetition◦High work intensity

OFTEN, MORE THAN 1 RISK FACTOR IS PRESENT

Hazard ElementsHazard Elements

Duration (how long?)Duration (how long?)

Frequency (how often?)Frequency (how often?)

Intensity (how hard?) Intensity (how hard?)

Working in front

Working at ground level

Working above the shoulders

Working at ground level, precision work

Working at ground level, confined space

Working above shoulders, confined space

‡From: Torner et al, 1991

Common postures adopted in Common postures adopted in weldingwelding

Awkward postures in workAwkward postures in workSevere torso

flexionTorso twistingKneeling, squattingBent wrists Neck

flexion/extensionShoulder

flexion/abduction (separation)

POSTUR DUDUKPOSTUR DUDUK

MANUAL HANDLINGMANUAL HANDLING

HAZARD ERGONOMI & BIOLOGIHAZARD ERGONOMI & BIOLOGI

Hazard human errorHazard human error

MUSCULOSKELETAL DISSORDERS

Repetition of work

High Risk Repetition Rates by Different Body Parts

Body Part Repetitions Per Minute

Shoulder More than 2½ Upper Arm/Elbow More than 10 Forearm/Wrist More than 10 Finger More than 200From Kilbom Å [1994]. Repetitive work of the upper extremity; Part II: The

scientific basis for the guide. Int J Ind Erg 14:59–86.