June is National Safety Month, as recognized by the National Safety Council, and each week they are focusing on a different safety topic. This week's focus is on ergonomics and how by taking action you can help to prevent injuries in your workplace. What is Ergonomics?
When workers have to adjust their bodies to do a job, over time there’s a high potential for developing a Cumulative Trauma Disorder (CTD). CTD, as defined by OSHA, is a class of musculoskeletal disorders involving damage to the tendons, tendon sheaths, and the related bones, muscles and nerves of the hands, wrists, elbows, shoulders, neck and back.
Ergonomics is the science of fitting workplace conditions and job demands to the capabilities of the working population. Its focus is fitting the job to the worker, not the worker to the job to help prevent CTD's. These effective “fits” result in higher productivity, injury risk avoidance and an increase in employee satisfaction.
Below we have outlined the risks in more detail and provided steps you can take to prevent injuries.
1) Repetitive Movements
The Risk -- Jobs that make workers perform a series of motions every few seconds with little variation produces fatigue and muscle-tendon strain. When not given adequate time to recover, the risk of tissue damage and other problems increase. A task cycle time of less than 30 seconds is considered repetitive. Also, awkward postures and external force decrease repetitions per minute.
The Resolution -- Allow the body performing repetitive movements to recover from strain and fatigue. Grant workers a 60 to 90-second break where they stop doing the activity. These breaks are recommended every 20 to 30 minutes. Having ideal posture also helps with repetitive movements, since bad posture falls under the risk factor of awkward/prolonged postures and magnify the hazard of CTDs.
2) Awkward/Prolonged Postures
The Risk -- Jobs that include any fixed or constrained body position that’s more than 20 degrees out of neutral is considered awkward. For example, if you work with your wrist bent in 45 degrees of flexion, 40% of your grip strength is lost. This means you have to exert 40% more force to perform the job task, creating strains and sprains that over time develop into debilitating injuries.
The Resolution -- You have to find the root cause and from there eliminate awkward postures with engineering and administrative ergonomic controls. Considerations of root causes are situations such as work height in relation to the worker or tools forcing awkward postures.
3) Excessive Force
The Risk -- There are two kinds of excessive force: internal and external. Internal forces result from prolonged awkward positions where the body must generate enough internal force to counteract the effects of gravity. External forces are generated when we lift, hold, push or pull an item, where the amount of force depends on where our hands are located in relationship to our body.
The Resolution -- Again, for internal force, you have to find the root cause and correct it with ergonomics. For external forces, like heavy materials handling, the use of mechanical assist devices reduces the risk of injury.
4) Arm/Hand Segmental Vibrations
The Risk -- Prolonged use of vibratory tools breaks down the small capillaries in the fingers, restricting blood flow. Although symptoms of segmental vibration takes years of exposure to experience symptoms, it could result in blanching of the fingers resulting from loss of blood flow.
The Resolution -- Vibration-damping materials such as gloves or tool wraps can control vibrations, so long as they don’t increase the amount of force required to hold the tool.
5) Mechanical Contact Stressors
The Risk -- There are two types of mechanical compression: internal and external. Internal occurs when muscles are held in a static contraction, which reduces blood flow to the nerves. External occurs when parts of the body come into contact with hard or sharp objects.
The Resolution -- Reducing or eliminated prolonged static postures, padding all sharp edges of workstations and tool handles, using tools that don’t end in the palm of the hand and using mechanical aids for hammering are all helpful options.
The overarching theme of the above CTD risk factor resolutions is to balance work demands with worker capacity. On the whole, we tend to work harder than necessary to get jobs done because of awkward postures and poor design. Meaning that working to solve CTDs through ergonomics results in decreased injuries but also increased efficiency.
Speak with an Arbill Safety Expert today, to learn more about Ergonomics and how to prevent Cumulative Trauma Disorders.
Have a Safe Day!