Chapter 10
Absence vs. presence of negative environmental factors
- more negative factors more stress
Keys to a successful ergonomics workplace analysis program
●Commitment on the part of top management ●Written program ●Employee involvement / training ●Continuous monitoring of the program ●Adjusting as necessary based on the results of monitoring
First step: Records analysis and tracking
- The essential first step in worksite analysis is records analysis & tracking to develop information to identify ergonomic hazards in the workplace - Incidence rates for upper extremity disorders and/or back injuries should be calculated
OSHA's ergonomic guidelines
- are voluntary but they use their general duty clause to enforce it - geared towards manufacturing and materials handling
CTD
- cumulative trauma disorder - umbrella term that covers a number of injuries caused by forceful or awkward movements repeated frequently over time
Work with hands above chest height
- problems with neck, upper body, and heart strain - ways to fix this: - eliminate manual lifting - use extensions arms and poles - machines with easy access below the horizontal plane of a workers shoulders
Training and education
- to ensure that employees are sufficiently informed about the ergonomic hazards to which they may be exposed and thus able to participate actively in their own protection - allows everyone to understand the hazards associated with the job, their prevention and control, and their medical consequences - should include means for adequately evaluating its effectiveness
Work hardening
a concept that is gaining acceptance in bridging the gap between treatment or therapy and a safe return to work
Step 3: Ergonomics job hazard analysis
- As an essential third step in the worksite analysis, an effective ergonomics program requires a job hazard analysis for each job so identified - Routinely performed by a qualified safety & health professional, preferably an ergonomist, for jobs that put workers at risk of developing CTDs - Helps verify lower risk factors and determines if risk factors for a work position have been reduced or eliminated to the extent feasible
Tunnel syndrome
- CTS - symptoms include numbness, tingling, and loss of gripping power
Second step: Baseline Screening surveys
- Detailed baseline screening surveys identify jobs that put employees at risk of developing CTDs - If the job places employees at risk, an effective program will then require the ergonomic job hazard analysis (step 3) - Surveys are performed with an ergonomic checklist tailored to the specific needs and conditions of the workplace
Large vs. small demand for strength/power
- jobs that demand larger amounts of strength/power are more stressful
Low vs. high surface contact
- more surface contact more potential for stress
Step 4: periodic ergonomic surveys, feedback, and follow-ups
- Periodic surveys should be conducted to identify previously unnoticed factors/failures or deficiencies in work practices or engineering controls - Should include feedback, follow-up & trend analysis - Encourage employee feedback! - They tend to be the first ones to identify hazards in the workplace - Trends of injuries and illnesses related to actual or potential CTDs should be calculated, using several years of data where possible
Ergonomics
- a multidisciplinary sciene that seeks to conform the workplace and all of its physiological aspects to the worker -it involves: - using slexial design and wvaluatkon techniques to make takss, objects, and environments more compatible with human abilities and limitations. - seeking to imrpove productivity and quality by reducing workplace stressors, reducing the risk of injuries and illnesses, and increasing efficiency - translates to work laws
Medical Management Program
- an effective medical management program for CTDs is essential to the success of an ergonomic program in industries with a high incidence of CTDs. - health care providers should be part of the ergonomics team, exchanging information routinely to prevent and treat CTDs properly - a standardized measurement should be developed to determine the extent of work-related disorder symptoms in each area of the plant - conduct an annual symptoms survey to measure employee awareness of work-related disorders and to report location/frequency/ duration of discomfort - if CTDS are recognized and treated properly early enough, a more serious condition can be prevented.
Common indicators of problems
- apparent trends in accidents and injuries - incidence of CTDs - absenteeism and high turnover rates - employee complaints - employee-generated changes - poor quality - manual material handling
Standing for heavy lifting and carrying
- back and muscle strain - ways to fix this: - eliminate manual lifting as much as possible - train workers in proper lifting techniques - provide sufficient room so they don't have to twist - supply correct PPE - keep floors clean to prevent slips - do not allow manual carrying of heavy objects upstairs
Seated repetitive work with light parts
- back, beck, shoulder, and lower leg pain - ways to fix it: - break the repetition - use job rotation - adjust height of work surface - adjustable chair - sufficient legroom
Cervical radiculopathy
- caused by holding a telephone receiver on an upraised shoulder while Typing. - compression of discs in neck, making it painful to turn neck,
Human factors
- consumers are demanding safe and effective products - is a profession to help ensure that equipment and systems are safe and easy to operate by human beings. - deals with humans and machines - also can be defined as a science that combines research with the application of human data
Hazard Prevention and Control
- engineering solutions, where feasible, are the preferred method for hazard prevention and control. - focus of ergonomics is to make the job fit the person. - effective engineering controls: - workstation design - design of work methods - tool design and handles
Stationary vs. moveable/mobile
- for stationary, physical stress can increase if the worker fails to periodically stand/stretch/move. - for mobile, it increases when workers carry materials as they move from station to station
Identifying specific ergonomic problems
- general observation (better when they don't know they're being observed) - videotaping and photography (good because freeze, playback, doesn't intrude) - drawing or sketching - measuring the work environment
Good vs. Bad vertical work area
- good: are not require to life their hands above their shoulder or bend down.
Good vs. bad horizontal work area
- good: does not require the worker to bend forward or twist body from side to side - bad: does this.
Benefits of ergonomics
- improved health and safety for workers - higher morale in the workplace - improved quality - improved productivity - improved competitiveness - decreased absenteeism and turnover - fewer workplace injuries and health problems
Seated work with larger parts
- involves interacting with objects that may be too large to manipulate manually, usually assembly and welding jobs. - usual problems are posture, illumination, reach, and lifting - ways to fix it: - use technology to lift and position the work for easy access that does not require bending, twisting, and reaching - supplemental lighting - adjustable workstation
Seated control work
- involves sitting in one location and using wheels, levers, knobs, handles, and buttons to control a process, system, or piece of equipment - problem is usually from excessive vibration or bending and twisting to achieve better visibility - ways to fix it: - an adjustable swivel chair with back and seat support - keep feet on floor - provide comfortable and convenient locations for control devices - sit with straight back and shift positions frequently - get up and walk around - provide ladder
Standing work
- leg, arm, back strains - adjustable machines and work surfaces - in machines, make sure there is a recess at the bottom for feet - provide ample free space around machines
Back safety/lifting program
- make proper lifting techniques visible - screen applicants (majority of people had back problems before they applied) - conduct safety inspections regularly - provide education and training - make use of external services - document program in writing
Work with hand tools
- most common problems CTS, lower arms, hands, and wrist strains - solutions: - tools that keep hands in the rest position - tools that have thick handles - tools with enhanced gripping surface - tools that don't require twisting
Tendinitis
- overworking a tendon that's causes small tears that become inflamed with intense pain
Work with VTDS
- personal computers in the workplace - solutions: - arrange keyboard properly - adjust work staton - tilted keyboard - soft touch when click mouse - avoid wrist resting - occasionally change hands - move VDT at a proper height and distance - minimize glare - reduce lighting levels - dust screen - eliminate telephone cradling - typing breaks
Proper lifting techniques
- plan ahead - Lift with your legs not your back - push, don't pull
Workplace analysis purpose and steps
- purpose: to identify stressors in the workplace, and eliminate them - records analysis and tracking - baseline screening surveys - Ergonomic job hazard analysis - period ergonomic surveys, follow-up, and feedback
CTD risk factors
- repetitive and/or prolonged activities - forceful exertions, usually with the hands (pinch grips) - prolonged static posture - inadequate tool design - vibration from power tools - continued physical contact with work surfaces - use of gloves
Non repetitive vs. repetitive
- repetitive: can lead to boredom. Which will lead to potential for physical stress
Workstation design
- should be designed to accolade the person who uses them. - adjustable work stations
Sitting vs Standing
- sitting is less stressful than standing - standing: can produce unsafe levels of stress on the back, legs, and feet. - sitting: can be stressful unless you use proper posture, a supportive back rest, and frequent standing/stretching movement
Design of work methods
- tasks should be altered to reduce force levels, static postures and repetition rates, arm and hand postures and other stresses associated with CTDS
Preventing CTDs
- teach employees the warning signs - teach employees how to stretch - teach employees to start slowly - avoid use of wrist splints - exercise regularly - select tools wisely
Anthropometry
- the science of body size, form, and function - used to study the interaction of workers with equipment, tools, vehicles, workstations, PPE - 3 somatotypes: - ectomorphs: tall and lean - endomorphs: lot of body fat and muscle mass - mesomorphs: fit strong and solid
Tool design and Handle
- tools should be selected and designed to minimize the risks of upper extremity CTDS and back injuries Ex.) - for both left and right handed people - triggers depress easily - distribute the pressure of the grip over the fleshy part of the hand - minimum weight tools - that exhibit minimal vibration - variety of sizes