The 4 types of muscle contraction, with examples

How do muscles work? How many muscles would you say we have in the human body?

In this article, in addition to answering these and other questions, you will see explained what is a muscle contraction and what are the different types of muscle contraction that exist. Here you will also find examples of each, through simple exercises or daily events.

    Muscles and how they work during exercise

    Before talking about the different types of muscle contraction that exist, it is necessary to know, in general, what a muscle is and what a muscle contraction consists of.

    As we all know, humans and animals have muscles all over the body, which cover our skeletons. More specifically, human beings we have around 650 muscles distributed throughout the bodyor, of different sizes. They are all voluntary muscles, that is, we can move at will (unless we have a pathology or disease that prevents it).

    Muscles are a type of organ made up of a fiber fabric that contracts and relaxes, Depending on the type of movements we perform. In other words, muscles allow movement.

    For its part, a muscle contraction is a physiological process in which the muscles develop a certain tension, and shorten or stretch (lengthen); they can also stay the same length, depending on the type of contraction.

    like that, muscle contraction is an effect on muscles that involves their fibers generating tension in themselves; as we have seen, this tension occurs in various ways, for example when the muscle is lengthened, shortened, moved, kept at the same length, etc.

      Types of muscle contraction

      In the field of bodybuilding and training, there are different types of muscle contraction depending on the exercises we perform and the muscles we want to train and strengthen.

      Here we will talk about the main types of muscle contraction that exist: isotonic contraction (which in turn is divided into concentric and eccentric), isometric, auxotonic and isokinetic contraction.

      1. Isotonic contraction

      The first of the types of muscle contraction is isotonic contraction, also called heterometric, which this is the most common contraction when we play most sports.

      The term “isotonic” means “of equal voltage”. In isotonic contractions, muscle fibers contract and change in length. In this type of contraction, the fibers of our muscles get shorter and longer.

      As we move forward, isotonic contraction, in turn, is divided into two types of muscle contraction: concentric and eccentric.

      1.1. concentric contraction

      In concentric contraction, the muscle acts, generating tension, to overcome a certain resistance.

      Thus, there is a shortening of the muscle fibers and subsequently a mobilization of a part of the body. For you to understand better, this type of movement would be like “focusing” the muscle.

      An example of concentric contraction would be an act as simple as taking a fork and putting it in your mouth, In which we observe how our biceps swell (in this case it is a concentric shortening). Another example, this time in sports, would be doing certain exercises with weights, such as curls with dumbbells.

        1.2. eccentric contraction

        In eccentric contraction, the second of the types of isotonic muscle contraction, the reverse occurs in the previous case. In this case, in the face of resistance, we exert tension on the muscle at the same time as we lengthen it. Simplifying would be like “stretching” the muscle.

        To illustrate this, an example would be lowering the bar to the chest in a bar exercise called a bench press (in the concentric phase we would raise the bar).

        2. Isometric contraction

        The second of the types of muscle contraction is isometric contraction, which it consists of a static contraction.

        “Isometric” means “the same size or length”. In this type of contraction, the muscle is static (that is, it does not lengthen or shorten, its length does not vary, as do other types of muscle contraction). In addition, a voltage is generated there.

        A clear example of isometric contraction would be take a toolbox and move it out of place; that is, we generate a certain tension in our arms, which remain static (to prevent the box from falling on us). As seen in this example, the muscle fibers in the arms do not lengthen or shorten, but are in a permanent position.

        Another example of an isometric contraction, in this case in sports exercises (gym), would be holding the barbell (bench press) for a few moments.

        3. Auxotonic contraction

        Another type of muscle contraction is auxotonic contraction. In this case, the two previous types of muscle contraction are combined (isotonic and isometric). In other words, for practical purposes: at the onset of muscle contraction, isotonic contraction occurs, followed by isometric contraction.

        An example of auxotonic contraction is stretching elastic bands (extensors) with the feet together (a type of exercise); in this case, we contract the muscles and hold them in the same position for a few seconds, then return to the starting position.

        That is, we stretch the muscle gradually and hold it in a certain position for a few seconds. There are many types of exercises to practice this type of contraction (as in other cases).

        4. Isokinetic contraction

        Finally, the last of the types of muscle contraction is isokinetic contraction. In that case, there is maximum muscle contraction, at constant speed, over the full range of motion of the muscle.

        This type of contraction is typical of sports that do not require acceleration of movement, such as rowing or swimming. As we see, in this type of sport, it is necessary to maintain a constant and uniform speed to advance in the water.

        In order not to be confused, we need to be clear about the difference between isokinetic and isotonic contractions (the former are discussed). When we perform isokinetic contractions, we are constantly regulating the speed of movement and exerting maximum tension throughout time. On the other hand, in isotonic contractions, we do not control the speed of the movement and do not always exert the same tension during it.

        Bibliographical references:

        • Correa, JE and Ermith, D. (2009). Principles and methods of muscle training. Collection of texts on rehabilitation and human development. Editorial University of the Rosary.
        • Mora, IS (2000). Muscular system. Sabinamora.
        • Vilanova, NG, Martínez, A. and Monge, AT (2007). Muscle toning. Theory and practise. Editorial Paidotribo.

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