Muscle Lab

This lab was to determine the effects of temperature and fatigue on muscle action.  It was interesting to see how fast a muscle wore down.  The first thing I did was to feel muscles that had contracted.

1.  The three changes I observed in a muscle while it was contracted was that it tightened, felt firmer, and was shorter in length.

Then I timed myself to see how many tight fists I could make in 20 seconds.  I was able to make 15.  After soaking my hand in ice water for a minute, that number went down to 12.

2. The cold temperature of the water caused my muscles in my hand to contract slower.  The muscles were slower to respond in making a fist.

The next part of my experiment involved fatigue.  I repeatedly counted how many times I could make a fist in 20 seconds.  I did this trial 10 times with no breaks in between.  My  husband wanted to attempt this also.  Here is the graph

4.  Fatigue made it a lot harder for the muscles to work.  It also caused muscle pain.  The number of times I was able to squeeze the ball steadily decreased.  My husband's decreased, then went up because he was forcing himself to try for opposite results, and then went steadily down again, leaving him sorer than I was.

In conclusion, both temperature and fatigue can slow down muscle function.