What type of muscle contraction occurs when there is no change in muscle length during the contraction?

An isometric contraction occurs when the muscle generates tension without changing its length. This type of contraction is commonly utilized in various exercises where the muscle is engaged and held in a position against a resistance but does not shorten or lengthen during the contraction. For instance, when you hold a plank position or press against a wall without moving, your muscles are contracting isometrically.

In contrast, concentric contractions involve the muscle shortening while producing force, such as during a bicep curl when lifting the weight. Excentric contractions entail the muscle lengthening under tension, like when lowering a weight back down. Dynamic contractions encompass both concentric and excentric actions, emphasizing movement and changes in muscle length.

Therefore, the defining characteristic of isometric contractions is the stable muscle length while still developing tension, making it the correct answer.