What is the type of contraction in which muscle fibers produce increased tension but does not shorten?

The type of contraction in which muscle fibers produce increased tension but do not shorten is called an isometric contraction. During an isometric contraction, the length of the muscle remains constant, but the tension within the muscle increases. Isometric contractions are often used in exercises such as planks, wall sits, and push-ups, where the muscles are engaged but not significantly changing length. They can also be used in rehabilitation exercises to strengthen muscles without putting stress on the joints.