26.Isotonic Contraction
Isotonic contraction refers to a type of muscle contraction where the muscle changes in length while generating a constant force. In isotonic contractions, the tension within the muscle remains constant, but the muscle fibers shorten or lengthen, resulting in movement at a joint. There are two types of isotonic contractions:
- a) Concentric contraction: This occurs when the muscle shortens while generating tension. It is commonly observed during the lifting phase of a bicep curl or when performing a squat. The muscle fibers contract and pull on the tendons, causing joint movement.
- b) Eccentric contraction: This occurs when the muscle lengthens while generating tension. It is observed during the lowering phase of a bicep curl or when descending in a squat. The muscle fibers gradually lengthen to control the movement and resist the external force.