OBJECTIVES Provide basic training regarding the identification, evaluation, and control of ergonomic exposures and hazards. This will include: The role of ergonomics Ergonomics-related injuries and their causes Proper workstation arrangement Controlling ergonomic hazards
The word Ergonomics comes from the Greek words “Ergos”--(work) and “Namos”-- (natural law). ERGONOMICS
ERGONOMICSERGONOMICS Definition: Ergonomics is an interdisciplinary approach toward adapting the manmade environment around man, rather than man around the environment.
ERGONOMICSERGONOMICS Definition: Ergonomics is the study of the relationship between the employee and the work place. It is a developing body of knowledge whose goal is to provide and maintain a healthy “user friendly” environment. Properly applied, ergonomic principles support each person's desire to find a zone of individual comfort.
Definition: Ergonomics is the study of how human beings relate to their work environment. The result of ergonomics is the adaptation of the workstation design and work tools to suit the individual performing a particular job function. The application of ergonomic principles to workstation design can result in increased effectiveness, work quality, health and safety, and job satisfaction. ERGONOMICSERGONOMICS
Why should we be interested? ERGONOMICSERGONOMICS The Worker (%) Men..........................34 Women......................65 Under 25 years.............11 25 to 54 years...............80 55 years and over...........7 Under 1 year of service...18 1 to 5 years..................35 5 years or more.............36 Not reported.................64
MANUAL HANDLING 9 1% of the total cost of Nelco Product’s WC claims for 4/93 through 4/94 Only 42 % of the frequency This means when MH losses occur, they are usually very severe and costly
OCCUPATIONAL BIOMECHANICS Definition: Biomechanics uses laws of physics and engineering concepts to describe motion undergone by the various body segments and the forces acting on these body parts during normal daily activities.
CUMULATIVE TRAUMA DISORDERS (CTD’s) Definition: Disorders that are caused or aggravated by repeated exertions or movements of the body.
CAUSES OF ERGONOMIC- RELATED INJURIES Posture Force Repetition Low temperature Contact points Vibration
CUMULATIVE TRAUMA Most back injuries are the result of everyday wear and tear rather than a single traumatic event. The cause is generally not a single lift but damage done over time. Causes: Repeated twisting Awkward postures Heavy lifting Prolonged vibration
CUMULATIVE TRAUMA Once back pain is experienced, the chances of it recurring increase greatly. Back injuries from slips, trips, and falls can sometimes be prevented by good housekeeping. Proper storage of material and regular cleanup of debris can improve access not only for workers, but for materials handing equipment.
To reduce back injuries on the job, a preventive program is necessary. An effective program should cover factors such as anatomy, work place posture, lifting techniques, ergonomics, and exercises.
Ramazzini in 1700’s wrote: Manifold is the harvest of diseases reaped by craftsman... As the...cause I assign certain violent and irregular motions and unnatural postures... by which... the natural structure of the living machine is so impaired that serious diseases gradually develop. (Tichauer, 1978)
SPINAL COLUMN AND MUSCLES Made up of bones called vertebrae Divided into five areas: Cervical (neck) Thoracic (upper back) Lumbar (lower back) Sacrum Coccyx The spine provides protection to the spinal cord The spinal cord has nerves that branch off and send messages to various parts of the body as well as bring back information on conditions throughout the body
VERTEBRAE AND DISCS Vertebrae are the bones that make up the spine. Provide support Offer protection Intervertebral Discs are made up of two parts. Outer part (fibrous ring) Inner part (soft, gel-like center) The discs are firmly attached to vertebrae, so cannot “slip.” If outer fibrous ring gets damaged, part of the gel part can start protruding out, called a disc protrusion or herniation.
VERTEBRAE AND DISCS 80-85% of people over 30 have protruded or herniated discs. However, the majority do not have pain. Why? Many theories exist, but the most widely accepted is that pain is felt when a protrusion or herniation occurs at the point where the nerve exits the spinal column. Age has an effect. Degenerative disc disease May cause flattening and hardening of discs and wears on the facet joints
SPINAL DISCS UNDER LOADS Discs are continually being compressed by the effects of gravity. our upper body loads we might be carrying Discs may become damaged when: carrying uneven loads (compression) or twisting combined with carrying (torsion)
SPINAL MUSCLES Movement controlled by muscles contracting and relaxing. Rope-like ligaments join bone ends to support and strengthen joints and prevent abnormal movements Interwoven sheath of muscle and ligaments across abdomen and lower back provide support. For this reason, it is important to keep them in good condition.
WORKPLACE POSTURE Dynamic vs. static Back muscles vs. stomach muscles back--short, small very strong stomach--large, broad when imbalance occurs, back muscles can become overloaded. thus, important to maintain health and good posture by using stomach muscles. Unbalanced pelvis stomach protruded pelvis tilted down back curve increases stresses lower back makes back vulnerable to injury tightening stomach muscles will straighten pelvis, lowing spine
CORRECT POSTURE Natural alignment, follows natural curves. Lordosis (sway back) inward curve neck low back outward curve (kyphosis) in upper back jams vertebrae together causes lower back muscles and ligaments to tighten and leads to low back pain Kyphosis (flat back) puts extra pressure on front of discs may contribute to low back pain Keeping spine aligned reduces everyday stresses on the back and minimizes the effects of the normal aging process on the spine.
H = The horizontal distance When H is increased, the crane’s capacity to lift the load is decreased. This is true with our bodies as well It is critical to lift and carry the load as close as possible LIFTING H H
PROPER LIFTING Plan your move –Size up the load and make sure your path is clear. –Get help as needed. –Use a dolly or other materials handling equipment if possible. Use a wide, balanced stance with one foot slightly ahead of the other. Get as close to the load as possible. Tighten your stomach muscles as the lift begins. When lifting, keep your lower back in its normal arched position Pick up your feet and pivot to turn. Don’t twist your back. Lower the load slowly, maintaining the curve in your lower back.
LIFTING GRIP Use entire palm, not just the fingertips.
LIFTING DO’S AND DON’TS DO: Push rather than pull. Keep a good grip. Maintain clear vision between the object and your destination. When lowering an object, try and keep the natural curve of your back. Place the load on the edge (tailgate) and push it back. DON’T: Lift above shoulder height. C atch falling objects.
TWISTING Repeated twisting of the lower back during lifting (or shoveling) is a common mistake. It can contribute to lower back pain and disability. Instead, lift your feet and turn you whole body. Lifting and placing palletized/stacked materials –lift object with feet and body in same direction –pick up feet and turn with feet and body together –don’t twist
MORE LIFTING TIPS Transferring weight –pull object towards you while transferring your weight to the lift side –lift only to the level required –shift your weight to the other leg while pushing the object into position. –do not twist Lifting heavy bags –put one knee down against bag –pull bag up leg –rest bag on edge of knee –stand upright –pull bag to waist height
LIFTING OVER BARRIERS Many back injuries result from repeated use of poor lifting techniques. Often a simple change in how we use our body to perform routine tasks can prevent back injuries and make work easier at the same time. One-handed lifts –Lifting with the back rounded and knees straight places great stress on the spine, making the lower back more susceptible to injuries Two-handed lifts –Again, avoid rounding the back –Move the object as close to the body as possible –Bend at the hips, while keeping the back in the normal arched position
MATERIALS HANDLING EQUIPMENT Different types of equipment have been designed and manufactured to lift and move loads of various shapes, sizes, and weights. This equipment can not only save time and labor---it can save your back! Rollers, wheelbarrows, carts, dollies, and rolling tables and scaffolds can be used to handle material efficiently and reduce the risk of back injury.
WORK TECHNIQUES Benches For bench work the right height is vital to reduce the risk of back injury or pain. Ideally the bench (work surface) should keep the work between waist and shoulder height. Tools Choose the proper tools for the job and repair or discard badly worn or damaged tools. Never use cheater bars for extra leverage on a wrench. Use the right length of wrench.