Final answer:
Isotonic contractions refer to muscle contraction that produce shortening of the muscle with constant contraction strength at a given load.
Step-by-step explanation:
In muscle contraction that produces shortening muscle with a constant contraction strength at a given load, it refers to isotonic contractions. Isotonic contractions are muscle contractions where the tension in the muscle remains constant, but the length of the muscle changes. There are two types of isotonic contractions: concentric and eccentric.
Concentric contractions occur when the muscle shortens to move a load. An example of this is when the biceps brachii muscle contracts to bring a hand weight upward. Eccentric contractions occur when the muscle tension diminishes and the muscle lengthens. An example of this is when the biceps brachii muscle slowly lowers a hand weight.