What is the Difference Between Origin and Insertion

The main difference between origin and insertion is that origin is the attachment point of skeletal muscles, which does not move during contraction whereas insertion is the attachment point that moves during contraction. Furthermore, the origin of the skeletal muscles is more proximal while insertion is more distal when considering the location of the attachment points.

Origin and insertion are two types of attachment points of a skeletal muscle. Generally, skeletal muscles form two or more attachment points while attaching to the bones through tendons.

Key Areas Covered

1. What is the Origin
     – Definition, Location, Movement
2. What is the Insertion
     – Definition, Location, Movement
3. What are the Similarities Between Origin and Insertion
     – Outline of Common Features
4. What is the Difference Between Origin and Insertion
     – Comparison of Key Differences

Key Terms

Attachment Points of Skeletal Muscles, Origin, Insertion, Movement, Muscle Contraction

What is the Origin

The origin is the end of a skeletal muscle, located more proximal to the centre of the body. During muscular contraction, the origin of the muscle does not move. Hence, it is the point of attachment which is relatively fixed. That means; the bone in this attachment point is also fixed.

Figure 1: Origin and Insertion of Biceps and Triceps

What is the Insertion

Insertion is the opposite end of the origin. Therefore, this attachment point occurs more distal to the centre of the body. Unlike the origin, the insertion moves during the contractions. So, the end of the bone which attaches with the insertion moves. Therefore, this part is responsible for the movement of a particular appendage in the body.

Similarities Between Origin and Insertion

• Origin and insertion are two types of attachment points which occur when skeletal muscles attach to the bones through tendons.
• Both types of attachment points are important in the movement of bones via muscular contractions.

Difference Between Origin and Insertion

Definition

Origin refers to the proximal end of attachment of a muscle to a bone that will not be moved by the action of that muscle. Insertion refers to the distal end of attachment of a muscle to a bone that will be moved by the muscle. Thus, these definitions contain the main difference between origin and insertion of muscles.

Movement of the Bone

To explain this further, the origin of muscle attaches to the less movable part of the bone while the insertion of muscles attaches to the more movable part of the bone.

Mass

Mass is another difference between origin and insertion of muscles. The origin of the muscle has more mass while the insertion of the muscle has less mass.

Movement

The origin of the muscle does not move during contraction while the insertion of muscle moves towards the origin during contraction. Hence, this is also a difference between origin and insertion of muscles.

Conclusion

The origin of the muscle is the point of attachment of the muscle, which does not move during the contraction. On the other hand, the insertion is the point of attachment of the muscle, which moves during the contraction. Also, the origin occurs more proximal to the centre of the body while the insertion occurs more proximal to the centre of the body. Therefore, the main difference between origin and insertion of muscles is the location and the movement of the muscle during contraction.

Reference:

1. Asher, Anne. “Muscle Origins and Stability With Movements.” Verywell Health, Available Here

Image Courtesy:

1. “Anatomy and physiology of animals Antagonistic muscles, flexion&tension” By Original uploader was Sunshineconnelly at en.wikibooks – Transferred from en.wikibooks; transferred to Commons by User:Adrignola using CommonsHelper. (CC BY 3.0) via Commons Wikimedia