26/11/2025
Concentric, eccentric, and isometric are three types of muscle contractions that describe how a muscle's length changes when it produces force. Concentric contractions occur when a muscle shortens under tension (like lifting a weight), eccentric contractions occur when a muscle lengthens under tension (like lowering a weight), and isometric contractions happen when a muscle generates tension without any change in its length (like holding a weight steady).
Concentric
What it is: A muscle shortens as it contracts, and the force it generates is greater than the resistance.
Example: Lifting a dumbbell during a bicep curl. The muscle shortens to bring the weight up.
Eccentric
What it is: A muscle lengthens under tension, and the force it generates is less than the resistance it's working against.
Example: Slowly lowering the dumbbell after a bicep curl. The muscle lengthens to control the descent of the weight.
Isometric
What it is: A muscle generates tension without changing its length or moving a joint.
Example: Holding a heavy object steady in place or pushing against an immovable wall.
Benefit: It can be used to strengthen a muscle in a specific range of motion and is useful for rehabilitation, as it can be done with less stress on joints, say the National Institutes of Health.
