Advanced Ergonomics If everything worked like it’s supposed to, most of us would be out of a job! ERGONOMICS IN 2000 AD WHAT DOES THE FUTURE HOLD? o Economics Issues Will Be A Factor Production Requirements An Aging Work Force CTD’s - Upper & Lower Extremities Back Pain Office Ergonomics Worker Compensation Health Practitioner’s AN EDUCATED WORK FORCE Aware of Ergonomics Aware of Worker Compensation $ Active Legal Profession ERGONOMIC RESEARCH Government Private Organizations Academic RESEARCH IN Repetitive Motion Vision Biomechanics Tools, Machines, and Equipment Noise Vibration Forms STANDARDS ANSI INTERNATIONAL GOVT. AGENCIES PROFESSIONAL ASSOCIATIONS If you do all the things that everyone or group desires you to do; will you have work?
Components of Ergonomics Anatomy: o Anthropometry o Biomechanics Physiology: o Work o Environmental Psychology: o Skill o Occupational Anthropometry: The deminisions of the body Biomechanics: The application of force Work Physiology: The expendititure of energy Environmental Physiology: The effects of physical elements Skill Psychology: Information processing & decision making Occupational Psychology: Training, effort & individual differences Source Singleton Introduction To Ergonomics Ergonomics Is: The Study of Work . . . . . . Fitting The Job/Task To THE PERSON . . . . . . Not Attempting To Fit The Person To The Job/Task Plant Ergonomics Committee Safety & Health Maintenance Industrial Engineering Union Safety & Health Representative Plant Engineering Medical Industrial Relations Ergonomic Coordinator Labor Plant Ergonomic Committee Activities Workplace & Methods Design Guidelines Management Awareness Training Future Machine & Handtool Purchase Guidelines Engineer, Supervisor and Wage Employee Training Tracking Cumulative Trauma Disorders Using Research
Ergonomic Program Barriers Lack of Ergonomic Knowledge Lack of Specific Job Knowledge Communication Barriers Between Departments Barrier of Self Interest Barriers to Change Three General Approaches To Minimize Program Barriers Top Management Commitment Training Participation By Those Affected Ergonomics And OSHA Recordkeeping Recommendations: Recordable Occupational Illnesses Must Be: 1. Work related Cumulative Trauma Disorder with: o Repetitive/Prolonged Physical Activity o Forceful Exertion o Awkward Posture o Surface Contact o Excessive Vibration o Cold Temperature 2. CTD Exists If: A. One Physical Finding (Test/Symptoms) Or B. One Subjective: - Symptom - MD Treatment - Lost Day/Duty - Transfer or Rotation Ergonomic Information Survey The normal routes of progression through jobs. Hiring patterns and turnover. Absenteeism, accidents, and medical restrictions. What is done to accommodate the worker with reduced capacity, such as a person who has a heart attack? Flexibility in moving people between jobs or between work groups. Shift-work schedules and overtime policies. Production pressures and perceived staffing adequacy for production goals Seasonal or infrequent work demands. Training programs and policies. Specific jobs or tasks of concern from a safety or performance standpoint, such as heavy lifting, difficult visual work or repetitive motion.
Determining Which Jobs To Evaluate Worker pushed by machine to perform tasks in a manner that increases fatigue or makes work difficult. Low incident rate but large number of affected workers. Entry-level jobs - turn over of workers moving to another jobs makes this an easy job to ignore Dirty, hot, uncomfortable conditions Total exposure of work population to a specific job. Worker-Task Match Match What the Worker Brings to the Job Anthropometric Characteristics Individual Work Methods Mismatch Body Size Considerations Allow range of users to fit work station and reach work and controls. Note variations with gender, age, ethnic background, etc.. Postural Considerations Avoid fatiguing posture except for infrequent, short duration tasks. Allow for posture changes, provide support when possible. Risk Factors - Repetitive Motions High frequency is a cycle time less than 30 seconds or more than 50% of the cycle involved in performing the same task. Risk Factors - Forceful Exertions High force is one that requires more than 9 pounds of hand force. Risk Factors - Repetitive Motions + Forceful Exertions High Repetitiveness + High Force = Increased Risk of Cumulative Trauma Disorder Risk Factors - Awkward Postures Overhead Work o Elbows above shoulders Extreme Reaching o Below and behind body Wrist Deviation o Flexion, Extension, ulnar/radial deviations Forearm Rotation o Inward and outward with a bent wrist What the Job Brings to the Worker Workstation Layout Hand tool Design Characteristics Production Quotas
Pinch Grip o 4-5 times as much force to hold with a pinch grip than a power grip
Reach Considerations - Standard Bench & Shelf
Five Primary Risk Factors For Cumulative Trauma Disorders: Body Posture & Position Vibration or Impact Static Position Long-Term Heavy Work Repetition
Solutions For Cumulative Trauma Disorders Stretch And Have Exercise Breaks Job Or Task Rotation Work Modification Early Intervention Early Treatment Golden Rule Of Lifting Push, Do Not Pull Move, Do Not Reach Squat, Do Not Bend Turn, Do Not Twist Six Guidelines To Better Work Efficiency 1. Avoid any kind of bent or unnatural posture. Bending the trunk or the head sideways is more stressful than bending forward. 2. Avoid keeping an arm outstretched either forward or sideways. Such postures not only lead to rapid fatigue, but also markedly reduce the precision and general level of skill of operations using the hands and arms. 3. Work sitting down as much as possible. 4. Arm movements should be either in opposition to each other or otherwise symmetrical. Moving one arm by itself sets up static loads of the trunk muscles. 5. Hand grips, operating levers, tools and materials should be arranged around the workplace in such a way that the most frequent movements are carried out with the elbows bent near the body and the arms bent around 90 degrees. 6. Hand-work can be raised up by using supports under the elbows, forearms or hands. These supports should be padded and should be adjustable to suit workers of different sizes. Three General Principles Of Hand Tool Design Use Special Purpose Tools Design Tools To Be Used By Either Hand Power With Motors More Than With Hands Design Of Hand Tool Grip Principles Use a power grip for power; use a precision grip for precision. Make the grip the proper thickness, shape, and length. Design the grip surface to be compressible, nonconductive, and smooth. Use the appropriate muscle group. Summary of Ergonomic Rules For The Work Place Body In Neutral Position - Maximum Rotation 45 Degrees No Lifting Below Knees Or Above Shoulders Wrist In Neutral Position, If Not, Palms Down Wrist Not Flexed, Extended, Or Deviated
Elbow Less Than 45 Degrees Out From Body Elbow Not In Front Of Body Elbow Not Behind Plane Of Body Hand Not To Be Used As A Hammer Work Near Elbow Height No Unusual Muscle Definition (Strain) Sit At Work Station Whenever Possible If It Looks Uncomfortable, It Probably Is!
QUESTIONS TO ASK - WHO IS THE USER? HOW SHORT IS THE SHORTEST USER? HOW TALL IS THE TALLEST USER? SPECIFIC CONCERNS BACKREST SEAT PAN ADJUSTABILITY CUSHION/PAD SUPPORT BASE ACCESSORIES COMMON PROBLEMS Lifting over 51 pounds or 1/3 - 1/2 body wt. Static Muscle Loading Frequent Handling - over 500 joint motions per hour or 2000 x’s per work shift Repetitiveness of Work Task Sudden Movements Carrying Object With Elbows “Winged” ERGONOMIC PROBLEMS Tool Use Creating Pressure & Pinch Points Vibration to extremities and/or body Grips Motions Exertion Posture Checklists, Magic? Or Myth? CHECK LISTS MUST IDENTIFY WORKER IDENTIFY JOB/DESCRIBE TASK IDENTIFY EVALUATOR GIVE TIME AND PLACE
DESCRIBE ENVIRONMENT IDENTIFY BODY ANGLES
LISTS DESCRIBE: BODY POSITION SPECIFIC TASK PERFORMED SHOULDER MOVEMENT FOREARM MOVEMENT WRIST POSITION HAND POSITION PRESSURE POINTS FORCEFUL MOTIONS LIGHTING NOISE/TEMPERATURE VIBRATION HAZARDS: TRIP, GUARDS MOVING PARTS LIFTS DESCRIBE WHAT YOU SEE THE MOST PROMINENT PHYSICAL DEMAND BODY PARTS WITHSTANDING LOADS BODY PART MOVEMENTS DISTANCE OBJECTS ARE MOVED POSITION OF SPINE REMEMBER PEOPLE COME IN ALL SIZES AND SHAPES? HOW HAVE WE DESIGNED OUR WORK STATIONS? DOES THE PERSON FIT THE JOB ? IT MAY MAKE A DIFFERENCE!!