Scientific Foundations: Ergonomics- Done Flashcards
Ergonomics is multidisciplinary, involving….
- Health professionals
- Engineers
- Behavioral scientists
- Physiologists
Purpose of ergonomics
- To prevent acute and chronic injuries
- Make worksites comfortable
- Enhance productivity
- Reduce fatigue and errors
- Promise job satisfaction
—– can make jobs appropriate for workers of both sexes
Proper job design
Proper job design considers
- Size
- Strength
- Visual capacity
- Hearing capabilities
- Limitations
Ergonomics seeks to ———– rather than the ——–
Job to the person
Person to the job
Several —— disorders can be caused or aggravated by work-site factors
Musculoskeletal
Musculoskeletal disorders can affect the following tissue structures
- Muscles
- Tendons
- Ligaments
- Peripheral nerves
- Blood vessels
- Joints
- Cartilage
- Bones
Locations of musculoskeletal disorders
- Upper extremities
- Lower extremities
- Cervical spine
- Lower back
Common symptoms of musculoskeletal disorders
- Pain
- Swelling
- Erythema
- Numbness
- Paresthesia
Major worksite risk factors for work related musculoskeletal disorders if the upper extremities are…
- Repetition
- Force
- Mechanic stress
- Awkward postures
- Low temperatures
- Vibration
Avoiding and minimizing these risk factors is the goal in….
Task and tool design
Repetition
Refers to the performance of the same or similar tasks again and again
What constitutes a repetitive task?
- One work cycle lasts less than 30 seconds (a series of motions that is then repeated)
- For cycles lasting several minutes there are subcycles that constitute more than 50% of the overall cycle
Force is exerted in tasks that require..,
- Lifting weights
- Handling heavy tools
- Pinching with the fingers
- Applying other grips
The combination of repetition and force is particularly associated with
Carpal tunnel syndrome
Mechanical stress
Refers to the forces that result from a worker’s direct contact with work surfaces or tools
Examples of compressive forces
- Striking objects with hand held tools
2. Leaning against hard surfaces or corners of work tables
Compressive forces can lead to..,
Nerve compression disorders
Work frequently requires workers to assume ——– for prolonged periods of time or repetitive shorter periods
Awkward positions
Deviation from neutral position —– been identified as a risk factor for injury
Has
Deviation from neutral posture has been associated with the following types of injuries…
- Cervical spine injury
- Back injury
- Shoulder injury
- Forearm/elbow injury
- Wrist/hand injury
Main posture related mechanism of cervical spine injury
Extreme neck flexion and twisting
Main posture related mechanisms of back injury
- Twisting at waist
- Lifting with legs straight
- Bending and reaching repetitively
- Carrying, pulling, pushing or lifting heavy objects from below the knees or above the shoulders
- Lifting weight beyond one’s capabilities
Main posture related mechanisms of shoulder injury
- Raising the arm or elbow above midtorso without support
2. Reaching behind one’s body