PSE 4U
Investigating Muscular Fatigue
Purpose:
Investigate how exercise (fatigue) and temperature affect skeletal muscle
performance.
Exercises
These exercises are to be done with a partner.
Station #1 Effects of muscle fatigue on performance.
1. Hold a clothes pin in the thumb and index finger of the dominant hand, and
open and close it while the other fingers of the hand are held out
straight. The number of times the clothes pin opens to its maximum
distance in 20 seconds is recorded. Attempt to squeeze the clothes pin
quickly and completely.
2. Repeat this process for nine more, 20 second trials, recording the result for
each trial. Do NOT REST the fingers between trials.
3. Repeat steps 1 and 2 for the non-dominant hand.
Trial
# of squeezes in 20 seconds
Dominant Hand
# of squeezes in 20 seconds –
Non-Dominant Hand
1
2
3
4
5
6
7
8
9
10
4. Prepare a line graph of the data you collected. The trial number should be on
the x-axis and the # of squeezes on the y-axis. You should have 2 sets of
data points on the same graph, one with the dominant hand, and one with the
non-dominant hand. Be sure you label the axis and title your graph.
Questions
1. What happened to your strength as you progressed through each trial? How
does your graph show this?
2. What effect did fatigue hand on the performance of your hand muscles?
3. Describe how your hand and fingers felt during the end of your trials.
4. What is the primary energy pathway (system) for this experiment/test?
5. What product from this pathway causes your muscles to be less efficient?
6. What type of skeletal muscle fibers are you using for this experiment/test?
7. Were your results different between your dominant hand and non-dominant
hand? Why do you think there was a difference.
Station #2 Effects of Heat and Cold on Muscular Performance.
1. Use the hand-grip dynanomemeter to asses the grip-strength of both hands.
Squeeze the dynamometer as hard as you can for about 3 – 4 seconds.
Record your score and then repeat with the other hand. Record your
TOTAL score.
2. Now submerge your hand in the pail of cold water/ice. Leave your hand in
the water for one full minute.
3. Remove your hand (dry quickly) and immediately squeeze the dynamometer.
Record your score.
4. Repeat steps 2 and 3 with the other hand. Record your score.
5. Now place each hand in warm water for a few minutes. Remove your hand,
dry quickly and squeeze the dynamometer. Record your score. Record your
total score.
Trial
Normal
Cold
Warm
Questions:
Right
Left
Total Score
1.
2.
3.
4.
What effect did the cold temperature have on your grip-strength?
What happened when your hand/forearm muscles were warmed back up?
What did the change in temperature do to your performance?
Why do dancers wear leg warmers, and major league pitchers wear jackets
before pitching?