Eccentric vs Concentric

Muscles are fibrous tissues that are powered by fat and carbohydrate oxidation and anaerobic chemical reactions. They are what produce force and cause the motions of the body by causing the changes in the size of cells. The process of producing force causes muscles to contract.

Contraction happens when motor neurons help the muscle fibers generate tension that can either be fast or slow. It can be involuntary such as in cardiac or smooth muscle contractions which are very important for survival. Skeletal muscle contractions, on the other hand, are voluntary because the forces that they generate can be controlled.
There are several classifications of muscle contraction and they are:

Isometric contraction wherein the muscles have the same length such as in holding up something and not moving it.
Isotonic contraction wherein even if the length of the muscle changes, the tension remains the same.
Isovelocity or isokinetic contraction wherein the forces may change but the velocity remains the same.
Concentric contraction wherein the muscles are shortened when they contract, and the force that is produced is enough to overcome resistance.

When a person lifts weights, such as in a bicep curl, the force which is generated is more than enough to carry the load and causes the muscles to shorten because the force is less than the muscle’s maximum capacity.

Eccentric contraction wherein the muscles are lengthened when they contract and the force that is generated cannot take on the resistance of the external force.

These contractions happen while a person is doing normal movements such as while walking. When the muscles are active, they lengthen because the external force caused by continuous walking can exert more force than what the muscles can generate.
This is also what happens when lifting weights that are too heavy. While the muscles are still contracting, they do not produce enough force to carry the load, and it causes them to stretch out and lengthen.
Eccentric contractions are more common than concentric contractions because they occur during the carrying out of normal activities. They are more associated with soreness and injuries, though, and for this reason it is important to strengthen the muscles through exercises which can in turn cause concentric contractions.

Summary:

1.Concentric contractions are muscle contractions that cause the muscles to shorten while eccentric contractions are muscle contractions that cause the muscles to lengthen.
2.Concentric contractions occur when the force generated by the muscles during activity is more than enough to overcome outside forces or resistance while eccentric contractions occur when the force generated by the muscles is not enough to overcome the load or resistance.
3.Eccentric contractions are more common than concentric contractions.
4.Eccentric contractions occur while doing normal activities such as in walking or moving the arms while concentric contractions usually happen during exercise.
5.Eccentric contractions are usually the cause of muscle injuries and soreness because they cause strain on the muscles while concentric contractions do not.
6.More studies are being done on eccentric contractions than concentric contractions due to their association with muscle injuries.

Sharing is caring!