There are three different types of contractions that your muscles can perform. Here is a brief description of each type.
By Rick Morris
ISOMETRIC CONTRACTIONS
An isometric contraction occurs when there is a contraction of the muscle, but there is no movement. This will happen when you are pushing or pulling on an immoveable object.
Competitive body builders will use isometric contractions when striking a pose in competition. Is that case, opposing muscle groups are exerting equal force in opposite directions.
Therapists will use isometric exercises for patients that have a restricted range of motion.
CONCENTRIC CONTRACTIONS
When your muscle is producing more force than the resistance you are using, your muscle will shorten. An example of this is the pulling up portion of a bicep curl. This type of muscle action is called a concentric contraction.
ECCENTRIC CONTRACTIONS
When the resistance used is more than the force produced by the muscle, the muscle will lengthen. The muscle is producing force, but it is “giving in” to the resistance. An example of this is the downward portion of the bicep curl, when the arm returns to its starting position.
