IE386 Discussion Qs: Exam 1 Questions And Answers

IE386 Discussion Qs: Exam 1 Questions And Answers When a person has his or her lower arm in a horizontal position and the palm is facing upward, why can he or she exert a greater upward force than a downward force? - ANS the mechanical advantage is greater when palm facing up because of the use of a different muscle group (the biceps) to counterbalance the load in the hand. What is the two-thirds rule relative to arm and leg strength and what are its implications in ergonomic design? - ANS Women aren't as strong as men of same age, weight, and physical condition, Difference depends on task performed, Women usually have ⅔ of men's strength Name three principal factors that affect muscular strength and state how muscular strength changes with each of these factors. Discuss how each of these factors affects designs of products that people use. - ANS Gender affects muscular strength as males tend to be stronger than females.; Oxygen supply to the muscles if low can cause lactic acid to build up causing the muscles to not perform at their full strength.; Exercise can grow muscles to become stronger over time When metabolism is measured by the rate of oxygen consumed, the metabolic rate increases rapidly at the onset of a physical task in an exponential fashion to meet the task requirements. Describe briefly what happens to the metabolic rate immediately after the individual stops performing the task and rests. Explain how this change in metabolic rate affects the design of jobs and job requirements. - ANS metabolism lags behind, so right after you finish something, the metabolism is still at a higher level What are ligaments, their elastic properties, and the role they serve in body movements? How does this knowledge relate to how products or hand tools should be designed? - ANS Ligaments connect two bones together; Most made of collagen fibers (inelastic); Some made of elastic fibers; Layer of collagen fibers together act as a shock absorber; Hand tools must take care that work operations do not cause joints to exceed their natural limitations in terms of force and direction of movement What is the technical term for total volume of the tidal, inspirational, and expirational reserves of the lungs at the maximum limit of air volume intake in a breath cycle. Why is measurement important medically? If this measure was used as part of personnel