Clothespin and Muscle Fatigue
Prelab
In order to contract (move), your muscles require energy in the form of ATP. (Adenosine
Triphosphate) Muscles can produce ATP 2 different ways. We discussed aerobic
respiration where oxygen is required. The second way is called anaerobic respiration
which does NOT require oxygen. Anaerobic respiration in muscles cells produces lactic
acid. When muscles do a lot of work quickly, the buildup of lactic acid reduces their
ability to contract, until eventually exhaustion sets in and contraction stops altogether.
This is called fatigue.
Prelab Questions (Answer these questions on a separate sheet of paper and staple to the
data table handout)
1.
2.
3.
4.
What is the type of energy that a muscle needs in order to contract?
What is produced when there is no oxygen present for the muscle cells?
When muscles use oxygen, what form of respiration is this?
What causes muscle fatigue?
Lab:
1. Hold a clothespin between the thumb and index finger of your dominant hand (the
one you use the most).
2. Count the number of times you can open and close the clothespin in 30 seconds,
while holding the other fingers of the hand straight out. Make sure to squeeze
quickly and completely to get the maximum number of squeezes for each trial.
3. Record the results in the data table
4. Repeat the process four more times, recording the number of squeezes.
5. Do not rest between trials.
6. Repeat steps 1-5 with your nondominant hand.
Lab Questions: (Answer these questions on a separate sheet of paper and staple to the
data table handout)
1. What happened to your strength as you progressed through each trial?
2. Describe how your hand and fingers felt near the end of your trial?
3. Were your results different for the dominant and the nondominant hand? If yes,
explain why?
4. Why did your muscles become weak and fatigued?
Name:
Period
Clothespin and Muscle Fatigue
DATA TABLE
(Circle your dominant hand, i.e. Are you right or left handed?)
Trial
1
2
3
4
5
Right Hand
Name:
Left Hand
Period
Clothespin and Muscle Fatigue
DATA TABLE
(Circle your dominant hand, i.e. Are you right or left handed?)
Trial
1
2
3
4
5
Right Hand
Name:
Left Hand
Period
Clothespin and Muscle Fatigue
DATA TABLE
(Circle your dominant hand, i.e. Are you right or left handed?)
Trial
1
2
3
4
5
Right Hand
Left Hand