Many different types of muscle contractions exist. In which type of contraction is muscle tension is generated, but the length of the muscle does not change?

In isometric contractions, muscle tension is generated but the length of the muscle does not change. Concentric contractions are a type of isotonic contraction in which the muscle shoens during the contraction. Eccentric contractions are also a type of isotonic contraction in which the muscle lengthens during the contraction. In isokinetic contractions, muscle tension is generated as the muscle contracts at a constant velocity over a full range of motion. Ref: Medical Physiology: Principles for Clinical Medicine Page 249.