Ergonomics questions will account for 13% or 26 questions of the ASP exam.

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2 Ergonomics questions will account for 13% or 26 questions of the ASP exam. This lesson will help in preparing you for those questions, to include several review and sample questions for practice. 2

3 Carpal tunnel syndrome is defined as an injury or inflammation of the carpal tunnel located in the wrist. This injury is common among repetitive motion workers. The median nerve is compressed, resulting in numbness, tingling, and sometimes pain in the fingers and wrist. A combination of cold and vibration often causes Raynaud's phenomenon or traumatic vasospastic disease. This is a condition, usually of the fingers and hands, characterized by pallor caused by a greatly diminished blood supply resulting from spasm of the blood vessel walls. In addition to white fingers, the victim may also experience numbness of the affected area. The disease is most prevalent among those who work with vibrating machinery in the cold. Typical occupations might bechain saw operators, jack hammer operators, and tamping tool operators. 3

4 Motivation in safety is highly situational specific, which means that situational or behavior specific campaigns (like don t drink and drive ) are more likely to have an impact than general campaigns (like Be Safe ). However, behavior change is likely to be short lived if it is unsupported or sustained by intrinsic beliefs. People are motivated to take risks as well as avoid risks so long as they perceive that they have some control over the risk. Frederick Herzberg (1966), in his book, Work and the Nature of Man, develops a motivation hygiene theory. The theory attempts to explain how persons are satisfied by certain intrinsic job factors, while being motivated by other intrinsic factors that are quite peripheral to the job being performed. 4

5 When dealing with human behavior, you are not dealing with the same degree of certainty as if you are working with a safety situation. The known fact that people differ has been referred to as the personal equation or as individual differences. The behavior of one person will always vary somewhat from the next person. At the bottom of Maslow's "Hierarchy of Human Needs" are the physiological or survival needs of food, water, and physical well being. 5

6 The majority of the behavior based safety experts agree that the most critical impact on work safety is team spirit, recognition, and attitude. The major factors in work discontent are company policy, interpersonal relationships, and supervision. In addition, the best way to reduce injuries and property damage in the future is to systematically reinforce positive employee actions and behavior. The safety culture is a group s attitude that everyone in the group will try to behave in a way that protects the safety of each other. Recognition will reinforce their trust in the culture. An important factor in developing a safety program is to incorporate the concepts of job enrichment, participation, and employee centered leadership. Management will most likely support a proactive safety effort when the prevention of losses relates to the achievement of company objectives. 6

7 People with normal cones and light sensitive pigment are able to see all the different colors and subtle mixtures of them by using cones sensitive to one of three wavelengths of light red, green, and blue. A mild color deficiency is present when one or more of the three cones light sensitive pigments are not quite right, and their peak sensitivity is shifted. Approximately 5% to 8% of the men and 0.5% of the women in the world are born colorblind. That is as high as one out of 12 men and one out of 200 women. People who are protans (which is red weak) and deutans (which is green weak) comprise 99% of this group. 7

8 The defenses that were available under common law to employers prior to workers compensation laws included: Assumption of risk: If the worker was aware that he or she was involved in a risky or hazardous occupation, he or she had no recourse because he or she accepted the conditions. Fellow servant rule: If a fellow employee had been the cause or contributed to the accident, no recovery was possible. Contributory negligence: If the worker had in some manner contributed to his or her own injury, the employer was relieved of responsibility. Foreseeability: The principle of foreseeability deals with liability for actions that result in injury or damage when the hazards were foreseeable. The principle of foreseeability is used as a fundamental legal principle in product liability cases. 8

9 In 1985, the National Institute for Occupational Safety and Health (NIOSH) convened an ad hoc committee of experts who reviewed the current literature on lifting, recommended criteria for defining lifting capacity, and, in 1991, developed a revised lifting equation. The Composite Lifting Index (CLI) is the term used in the revised NIOSH Lifting Equation to denote the overall lifting index for a multi task manual lifting job. The multi task procedure is quite complicated and involves more than just the calculation of the RWL. Be sure to visit the NIOSH publication for further information. 9

10 Review the example question provided, and click the box to listen to an expert s explanation and response to this type of test question now and on the next few slides. The NIOSH lifting formula is a very difficult question. It is a very time consuming question. The only good news is that the test will provide you with the formula. So, there is no memorization of the formula. However, you still need to know what the movements are in the question to insert them appropriately in the formula. 10

11 There are two versions of the NIOSH lifting formula. One is imperial in pounds and inches. The second is metric in kilograms and centimeters. Since our movements are in centimeters, we are going to default to the metric version. The 36 centimeter version represents the horizontal travel in our lift. That is our H. The 64 centimeters is the starting vertical, or the point at which we begin our lift that is our V. The 20 centimeters, the second vertical, is our stopping point that is not the D or distance it is part of the D. So, we take the 64, where we started, and the 20, where we stopped, and we find a difference of 44 centimeters meaning, the box actually traveled 44 centimeters during our lift. That becomes our D, or distance. Since there was no twisting, our asymmetric, or A, is a zero. It said we are going to lift once every five minutes for three hours. We derive this from a table. It said the coupling was good, so we go to the coupling table to find the numerical equivalence. 11

12 The one lift every five minutes is actually reflected on the table as.2 lifts a minute. You cannot do.2 lifts a minute. It takes five.2s to complete a lift. Each movement is a minute. So, five movements would be five minutes. It then asks us: Were we lifting for two hours but less than eight hours? We were; we were at 3 hours. And then it asks a question: Was our starting V less than 30 inches, or was it less than or equal to 30 inches? You will come to find that 30 inches is equivalent to 75 centimeters. They actually use 2.5 as the conversion instead of 2.54, and you are going to see this because of what is in the formula as well as what is on the coupling table. 12

13 The coupling table is very straight forward. We had good coupling, we go to the good line, and then we answer the vertical question. Was our starting V less than 30 inches (75 centimeters), or were we equal to or greater than 30 inches (75 centimeters)? Since we were at 64 centimeters, which is less than 75 centimeters, our coupling is a one. 13

14 Now, we take all of these numbers and insert them into the formula. Our H was 36 centimeters. Our starting V was 64 centimeters. Our stopping V was 20 centimeters a difference of 44 centimeters or, in other words, the travel of the box was 44 centimeters the D. There was no twisting, so our asymmetric was a zero, and from the frequency table, we got.85, and from the coupling table we got a one. Now, we go to insert these into the formula. Our first issue is with the vertical. 64 minus 75 would actually give us a negative number. The vertical lines inside the parentheses indicate an absolute value. In simple terms, an absolute means we cannot have a negative number. So, you have to perform that math outside the calculator before you insert it into the line. Since our asymmetric was a zero, a number times a zero is zero. So, one minus a zero is simply a one, and a one times the 23 kilograms in the formula is a perfect condition; it has no impact on the RWL. Be carful; put in all of your parentheses. Run your math, and with any luck, you should get Now, since we wanted to pick up 12 kilograms, 12.1 is actually more than 12 kilograms, meaning we can actually lift as described. 14

15 This question should always follow an RWL question because this is a tag along, or what is called a serial question. We cannot do this question correctly without the correct RWL. There is a simple formula for lifting index. It will be provided. So, you simply go back, and insert your numbers. 15

16 The lifting index formula is: Take the load and divide it by the RWL. In this case, the load was the 12 kilograms we wanted to pick up in the previous question, divided by the RWL the 12.1 kilograms we got from running the NIOSH lifting formula. So, it simply becomes 12 divided by Now, we desire an answer less than one. One representing the 100 percent of our lifting capacity. What this.992 represents is we are 99.2 percent of our lifting capacity, meaning there still is a little bit left where we could do slightly more lifting. 16

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