Ergonomics - Bowen Flashcards
What is ergonomics?
The study of human characteristics for the appropriate design of the living and work enviornment.
What is anthropometry?
The scientific study of the measurements and proportions of the human body.
Design workplaces for 90% of the population
What are musculoskeletal disorders?
- Disorders of muscles, nerves, tendons, ligaments, joints, cartilage, or spinal disks
- Not typically a result of an acute event
- Diagnosed by medical history or medical tests
- Distinct features of recognized diseases or characterized by location
What are occupational risk factors for musculoskeletal disorders?
- Repetition / duration
- Joint deviation
- Force
- Cold
- Vibration
What are non-occupational risk factors for musculoskeletal disorders?
- Rheumatoid arthritis
- Endocrinological disorders
- Acute trauma
- Obesity
- Pregnancy
- Recreational activities
- Diabetes
What is tendon?
Connects muscle to bone
What is a ligament?
Connects bone to bone
What body parts are at higher risk for a musculoskeletal disorder?
- Soft tissues
- Nerves
- Blood vessels
- Lower back
What is carpel tunnel?
- Often caused by light, repetitive motions of the wrists and fingers
- Carpal tunnel on the palmar side of the wrist contains nerves, blood vessels, tendons
- Swelling tendons pinches the medial nerve
What is DeQuervain’s syndrome?
- Special case of tenosynovitis at the base of the thumb
- Caused by gripping and hand twisting
What test can yo do to determine carpel tunnel syndrome?
Phalen’s test
What test can you do to determine DeQuevain’s syndrome?
Finklestein’s test
What is epicondylitis?
- Tennis elbow
- Tendons on the outside elbow injured or strained
- Caused by impacting or jerky throwing motions, repeated forceful wrist extensions
What is medial epicondylitis?
- Golfer’s elbow
- Tendons on the inside of the elbow injured or strained
What is tendinitis?
- Inflammation of the tendons
- Associated with repeated tension, motion, bending, contact with hard surface vibration
What is tendosynovitis?
- Synovial sheath swells
- Tendon becomes irritated, rough, and bumpy causing pain
What is trigger finger?
- Special case of tenosynovitis
- Finger movement not smooth (snaps or jerks)
What is white finger? (Raynaud’s phenomenon)
- Insufficient blood supply causes blanching
- Arteries closed due to vasospasms triggered by vibrations
Name the four ways an object can vibrate
- Continuous
- Intermittent
- Impulsive
- Impact
What is the hand-arm segmental vibration TLV?
- range from 4 m/s2 to 12 m/s2
What is the TLV for whole body vibration?
- Ranges from 010 m/s2 to 80 m/s2
- Separate table for longitudinal and horizontal vibrations
What are risk factors for low back injuries?
- Posture
- Frequency
- Static work
- Handles, coupling
- Asymmetrical handling
- Space confinement
Is horizontal movement (push, pull) less stressful than vertical movement (lift, lower)?
Yes
What is the best range for lifting and lowering?
- Knuckle height to shoulder height
- Keeps loads close to and in front of the body
What ergonomic TLVs exist?
- Hand activity level (HAL)
- Lifting
- Hand-arm vibration
- Whole-body vibration
What is the NIOSH lifting equation?
RWL = LC x HM x VM x DM x AM x FM x CM
What is the lifting index formula?
Lifting index = actual weight / RWL
What does a lifting index of more than 1 indicate?
An increased risk of lower back injury and should be redesigned
What are four things to avoid with tool design?
- Avoid high contact forces and static loading
- Avoid extreme and awkward joint positions
- Avoid repetitive finger action
- Avoid tool vibration
How should the wrists be oriented with respect to the forearm when using hand tools?
Wrists should stay straight with respect to the forearm
How high should a standing workstation be when performing delicate work?
2’’ to 4’’ above elbow
How high should a workstation be when performing light work?
2’’ to 4’’ below elbow
How high should a workstation be when performing heavy work?
4’’ to 6’’
What is illumination?
Amount of light hitting a given source
What unit is used for illumination?
Footcandle = 1 lumen/ft2
What is a lumen?
Total light output
What does poor illumination cause?
- Drowsiness or fatigue
- Decreased efficiency
- Decreased production
- Lowered morale
