- Your best friend has challenged you to an arm wrestle. Since you have never won an arm wrestle before, you now apply your biomechanical understanding to the situation in hopes that you will win. You cannot change the maximum force potential of your biceps within the next few minutes, but you can adjust the length of your muscle and the joint angle of your elbow. Therefore, how would you adjust these two factors in an arm wrestle to ensure maximal curling efficiency of the biceps about the elbow?
- Watch the following video in the file section of this order and briefly explain which of the three tools are easier for lifting the chamber lid? What does make the CLRT (chamber lift removing tool) different than the other tools?
- The concept of a moment arm was presented in this chapter. As an ergonomist you are conducting an assessment of landscapers. You notice that many the of the workers who are shoveling have their hands close together on the shovel handle as they lower topsoil into a garden bed. One worker complains of muscle strain while doing this task. Using the concept of moment arms, analyze this job in the following phases. (1) What class of lever is created by the human-shovel interaction? (2) Compared to the other classes of levers how does lever rank in mechanical efficiency? (3) What components of this lever can be modified to make work easier for the labourer?
- You are approached by a school board director in your region. She is about to purchase 100 shovels for the custodian workers in her schools. She mentions that she saw a commercial of a new ergonomic shovel and provides you with the web link, http://www.snoeasy.com/ (just in case this link didn’t work, search for “sno easy you tube” in your browser). She asks you to check out the shovel and see if it is really better than regular shovels. She is concerned about her aging custodial staff and would like to minimize their physical strain.Therefore, (1) go to the website, (2) analyze the mechanics of the shovel using the concepts outlined in this module, (3) determine if the modified mechanics would have an advantage over a straight handled shovel, (4) explain your conclusion to the school board director.
- You are the lead ergonomist at an auto parts manufacturing plant. The production engineers are complaining about the lack of quality assembly being performed by an employee who is working on the line. His job involves using a metal grinder, weighing 12 pounds, to grind down metal rivets on a chassis frame. The engineers complain that he grinds with little accuracy and sometimes misses the rivets or grinds the area around them, thus damaging the product. They ask you to evaluate the problem and determine if the employee or the job setup is the problem. Using the information from the above neurology / motor behaviour section, define the reason why the employee has a difficult time making accurate grinds with a heavy grinder. State your answer as if you were talking to the production engineers.
Sample Solution
