Cellular Respiration Activity – Clothespins and Muscle Fatigue

Purpose: to explore the relationship between cellular respiration and muscle fatigue

Materials: Clothespin, timer

Procedure:

1. Hold a clothespin in the thumb and index finger of you dominant hand.

2. Count the number of times you can open and close the clothespin in a 20 second period while holding the other fingers of the hand straight out. Make sure to squeeze quickly and completely to get the max number of squeezes for each trial.

3. Repeat this process for 6 more 20 second periods, recording the result for each trail in a suitable table.

Try not to rest you fingers between the trials.

4. Repeat this procedure for the non-dominant hand.

5. Prepare a suitable graph.

Observations:

	Number of squeezes in 20 seconds (Right Hand)	Number of squeezes in 20 seconds (Left Hand)
Trial 1	71	84
Trial 2	80	3
Trial 3	89	80
Trial 4	82	77
Trial 5	101	69
Trial 6	87	58
Trial 7	79	65

Analysis:

The number of squeezes on the right hand (dominant hand) followed a varied trend. In contrast, the number of squeezes on the left hand (non-dominant hand) followed a negative trend.

Discussion:

1. What happened to your strength as you progressed through each trial?

After each trial, my strength in my fingers decreased i.e. my hand became more tired. However, since I had to record the time and reset the stopwatch, I had time to rest my hand and therefore there are some fluctuations in the data.

2. Describe how your hand and fingers felt during the end of each trial?

After the end of each trial, my fingers felt like they were burning kind of like after I played piano for a long time. There was some pain as well in the muscles.

3. What factors might cause you to get more squeezes (to have less fatigue)?

- Doing the motion regularly (through the lab itself and through other means daily, i.e. typing of the keyboard.

- Drinking caffeine (coffee) or sugar in the morning

4. Were your results different for the dominant and the non-dominant hand? Explain why they would be different.
The results for the dominant and non-dominant hand were fairly different from each other. The non-dominant hand had a fewer number of squeezes on average than the dominant hand. This is because I use my right hand (dominant hand) more often than my left hand, so my right hand is more used to doing “work” (e.g. writing with a pencil).

5. Your muscles would probably recover after 10 minutes of rest to operate at the original squeeze rate. Explain why.

The lactic acid (that is produced during exercise and causes the muscle sores after the exercise) is removed and reduces the stiffness of the muscles so that the fingers can resume the squeezing.

Conclusion:

It was found that in general, the number of squeezes of the clothespins reduces overtime. However, as there was a brief rest between each trial, the number of squeezes for the dominant hand is more varied. It was also found that the left hand (non-dominant hand) had a decreasing trend on the graph. There was a substantial difference between the dominant and non-dominant hand as the dominant hand is more used to doing things than the non- dominant hand.