A(n) contraction occurs when a muscle lengthens under constant tension. An example of this type of contraction is the biceps brachii lengthening while slowly lowering a dumbbell.
Group of answer choices
eccentric
isometric
hyporeflexia
concentric
hyperreflexia
The correct answer and explanation is:
The correct answer is eccentric.
An eccentric contraction occurs when a muscle lengthens while still generating tension. This type of contraction happens when the muscle is working to resist a force, such as when you slowly lower a weight. In the example of the biceps brachii, the muscle is trying to resist gravity as the dumbbell is lowered, causing it to lengthen while maintaining tension. Eccentric contractions are typically involved in controlled movements where muscles elongate under load, such as in walking downhill or during certain athletic activities.
In contrast, isometric contractions involve muscle tension without any length change. An example of isometric contraction is holding a weight in a stationary position, like holding a dumbbell in place at a certain angle without moving it.
Concentric contractions, on the other hand, involve muscle shortening as it generates tension. For example, when you lift the dumbbell, your biceps brachii shortens as it contracts to raise the weight.
The terms hyporeflexia and hyperreflexia refer to conditions involving reflex responses, not muscle contractions. Hyporeflexia indicates a decreased or absent reflex, whereas hyperreflexia refers to an exaggerated reflex response.
Eccentric contractions are important for muscle development and strength because they require muscles to work under tension while elongating, leading to muscle fiber growth and increased force production. These contractions are also associated with muscle soreness after intense exercise due to the microscopic damage caused to muscle fibers during the lengthening phase, which then rebuilds stronger over time.