What are two types of isotonic contractions eccentric and concentric. What movement action is described by each of these terms?

Isotonic contractions involve muscle shortening or lengthening while maintaining a constant tension. Concentric contractions occur when a muscle shortens as it generates force, such as lifting a weight during a bicep curl. Eccentric contractions happen when a muscle lengthens under tension, like lowering the weight back down in a controlled manner. Both types are essential for various movement actions in strength training and daily activities.