Science Buddies: "Ask an Expert"

I am doing a project of the effects of typing on carpal tunnel syndrome. I am trying to build a model of a hand with Popsicle sticks, i have successfully built the fingers, but I am having trouble trying to build the most important part: the carpals (wrist bones). In addition, I do not know how I can measure the amount of pressure on the carpals by typing. It would be awesome if you could help me figure out how to build the carpals and how to measure pressure. Thank you SO much

anushasyed,

Ok, so I'm not an expert in this field, so I don't know much about the biology involved. But as a mechanical engineer and what I can find about the structure of the wrist, here is an idea...I the wrist has movement vertically (up and down), and some laterally (side to side). Axial rotation is from the forearm. Given all this, I would model the wrist with hinges that approximate the movement outlined above. To then you could use springs to restrict the movement and measuring deflection, can determined the force required given the spring constant of the springs used.
Hope this helps,
theborg

Can you explain a bit more about the purpose of your project/experiment? Typing is a repetitive motion rather than a high stress activity. Are you trying to show how the repetitive motion causes a change in the muscles or connective tissue? And, if so, how one might prevent that by better positioning at the keyboard or taking exercise breaks during long report-writing activities (or gaming for that matter)? Think about how it feels if you simply flex you index finger repeatedly. After a very short period it becomes difficult and your finger motion slows down. You might run an experiment on how long it takes individuals to experience motion difficulty doing a repeated exercise. You might also try stretching a rubber band repeatedly. After a few stretches feel the rubber band and note the increase in temperature. Muscles are a bit like that rubber band and experience fatigue when used repeatedly. A Google search turns up some interesting resources: https://www.google.com/search?source=ig ... 7j1j1l24l0. The first one on the list includes both causes and ways to prevent RSI: http://www.google.com/url?sa=t&rct=j&q= ... ssdeBHbDcw.

Hope this helps.