In our body, muscles help in the movement of our body and protect and act as a shield for our bones and various organs present. To perform various activities in day-to-day life for a human, his muscles need to perform these actions.
There exist contractions between the muscles that let us perform our activities and their smooth functioning. Isotonic and isometric are two types of contractions available in the muscles.
Key Takeaways
- Isometric contractions involve muscle contractions without any change in muscle length or joint movement.
- Isotonic contractions involve a change in muscle length or joint movement.
- Isometric contractions are essential for building muscle strength and stability, while isotonic contractions are essential for building muscle endurance and improving overall physical fitness.
Isometric Contractions vs Isotonic Contractions
The difference between isometric contractions and isotonic contractions is that when an isometric contraction takes place in a human body for performing various activities, there is no change in the length of a muscle, and, on the other hand, when an isotonic contraction takes place in the human body, there is a change in the length of the muscles.
Isometric contractions are contractions that are said to be of the same length of waves. In this word, iso means some, and metric means length. The tension in a muscle increases to exceed the load that is initially carried on without changing the length of the muscles.
This, in short, means there will not take place any chance of exceeding the opposite force.
Isotonic contractions are contractions that occur with some tension.
The word isotonic is framed from a Greek word named is, which means some and toniko, which means tensions. In isotonic contractions of muscles, there is a change in the lengths of muscles, but the tensions are the same or contracted.
A certain amount of tension or contractions are exerted in an isotonic contraction.
Comparison Table
| Parameters of Comparison | Isometric Contractions | Isotonic Contractions |
|---|---|---|
| Length | There is no change in length. | There does occur some changes in length. |
| Tensions | There are some changes that occur in tension. | There is no change in tensions; that is, they are always constant. |
| Period changes | The latent period and relaxation period is inversely proportional to the contraction period. | The latent period and contraction period inversely proportional to the relaxation period. |
| External work | There is a non-occurrence of external work. | There is occurrence of external work. |
| Energy | High efficiency of energy is required. | Low efficiency of energy is required. |
What are Isometric Contractions?
Isometric contractions are contractions that are said to be of the same length of waves. In this word, iso means some, and metric means length. The tension in a muscle increases to exceed the load that is initially carried on without changing the length of the muscles.
This, in short, means there will not take place any excess for the opposite force.
When a person holds his or her length against his or her body till this person faces no resistance, he or she will have no change in his or her body length. This is exactly how an isometric contraction takes place inside the muscles.
During isotonic contact, the muscles remain at their normal length. This means that the amount of force produced is directly proportional to the amount of increase in the length of the muscle pull.
Pushing an object in a stationary position, or a person holding a weight in a special place are two examples where an isometric contraction takes place in a muscle.
Although there is no change in the length of muscles, there does occur a change in the muscle fibres to shorten, which helps to increase the strength of muscles.
What are Isotonic Contractions?
Isotonic contractions are contractions that occur with some tension. The word isotonic is framed from a Greek word named is, which means some and toniko, which means tensions.
In isotonic contractions of muscles, there is a change in the lengths of muscles, but the tensions are the same or contracted. A certain amount of tension or contractions are exerted in an isotonic contraction.
At this time, there is a specific amount of change in the muscles without any change in tension. This helps to activate the skeletal muscles in our body.
When it comes to moving limbs in mammals, that is when an isotonic contraction takes place. When a person runs, walks, exercises, or even sits, an isotonic contraction occurs.
Depending on the force to be applied to a person’s activity related to his or her body, the isotonic contraction is divided into some contractions.
They are the concentric concentrations that happen when the muscles require more force to shorten the muscle fibres and the eccentric contractions, which cause a muscle to elongate by giving more force.
Main Differences Between Isometric and Isotonic Contractions
- There are a lot of changes in the length of muscles in an isometric contraction, and, on the other hand, there does not occur any change in the length of a muscle in an isotonic contraction.
- In an isometric contraction, when there is a long latent period, there are shorter contraction periods with longer relaxation periods, and, on the other hand, in an isotonic contraction, when there is a shorter latent period, there occur shorter contraction periods with a longer relaxation period.
- The isometric contraction requires high efficiency of energy to be produced; on the other hand, an isotonic contraction requires less energy efficiency.
- There is a non-happening of external work in an isometric contraction due to less amount of heat released, and, on the other hand, there is a happening of external work in an isotonic contraction due to its high amount of heat emitted.
- The tension in an isometric contraction is always constant; on the other hand, the tension in an isotonic contraction keeps changing.
- https://rupress.org/jgp/article/56/6/732/13113
- https://journals.physiology.org/doi/abs/10.1152/jappl.1999.87.5.1758
Last Updated : 16 June, 2023
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Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.
This article overcomplicates the concept, making it harder to grasp the practical implications of these contractions. A simpler approach would be more effective.
I found the explanation to be clear and well-supported. It’s subjective how complex is too complex for different readers.
I see your point, but complex topics like these require a more detailed explanation to do them justice.
The article excels in digging deep into the mechanics of muscle contractions, making a complex subject accessible and engaging.
I’m impressed with the level of detail and how it’s communicated. It’s a commendable piece for scientific literacy.
Absolutely. It strikes a great balance between academic rigor and readability, appealing to both scientific and general audiences.
Well-researched and presented in a structured manner. The article is a valuable resource for those seeking an in-depth understanding of muscle contractions.
This article adeptly demystifies the complexities of muscle contractions, offering clarity on a challenging topic.
I couldn’t agree more. The detailed comparison and definitions clear up any confusion about the subject.
Definitely. The article’s clarity is commendable, especially considering the intricate nature of isometric and isotonic contractions.
A well-presented and meticulous examination of isometric and isotonic contractions. The thoroughness is invaluable for educational purposes.
The article’s tone is slightly dry, which may deter some readers. A touch of liveliness could make the content more engaging.
I understand the sentiment, but scientific subjects require a more formal tone. It’s a balance to strike.
An exceptional exploration of muscle contractions, providing a solid foundation for further understanding.
A fantastic examination of the mechanics behind muscle contractions. The article is a testament to thorough research and an analytical approach.
The article provides an insightful and comprehensive view of isometric and isotonic contractions, helping readers to understand the fundamentals of muscle movements. Great work.
Informative indeed. I appreciate the scientific approach used throughout the article.
Absolutely, the comparison table is very useful to understand the differences. I learned a lot.
While the content is informative, the tone seems a bit too academic, making it less engaging for casual readers.
From an educational perspective, I think the article’s formality is appropriate. It’s a matter of the target readership.
I agree with you. A more friendly approach could make it more accessible for a wider audience.