Want to work out muscle groups well? You definitely need to know the mechanics of your body. Find out how bodybuilders give their 100% during training. Human musculature is designed to perform motor function for the whole organism as a whole and for individual components. Thanks to the muscles, a person can perform various movements and maintain a stable position in space. Exercise can cause the muscles to become fatigued, causing a temporary decrease in performance. Fatigue is normal and goes away quickly. The situation is quite the opposite with overwork, which causes a gradual accumulation of fatigue.
All muscles can be divided according to various criteria. However, athletes do not need to go into the anatomy of the deep and it is enough to navigate in several concepts. Flexors are muscles designed to bring together the surfaces of individual limb components separated by a joint (s). In turn, the extensors are called the muscles that bring the posterior surfaces of the limbs together. It should also be remembered that synergists are muscles that perform friendly in the direction of movement. Those muscles that are designed to perform opposite actions are called antagonists.
Mechanics of Muscle Movement
During their contraction, the muscles move the bones, which are used as leverage. At this time, there is a slight shortening of the muscle, which allows you to develop great efforts. This fact explains the presence of bones in the human body, which lose muscles in work, but gain in the way of applying effort. The indicator of the moment of force during the work of the muscles directly depends on the angle at which this force acts on the lever. The maximum will be the indicator at the moment the force is applied at an angle of 90 degrees with respect to the lever.
When you change the angle when flexing, for example, the elbow joint in the range of 0-100 degrees, the shoulder strength increases by about 11-44 millimeters. Simply put, at a 90 degree angle, the force will be four times greater than at a zero angle. At the same time, the real value of the moment of force is much less, since the force almost never acts on the lever at an angle of 90 degrees.
For more effective action on the levers, bones have various tubercles, protrusions and sesamoid bones. Those muscles that cause movement of body elements in only one joint are usually called single-joint. There are also muscles that attach to different parts of the skeleton and they are called polyarticular muscles.
When articular movement is performed due to the contraction of the synergistic muscles, then the moved element can be returned to its initial position with the help of the antagonist muscles. This statement is true in the absence of an external load. The strength indicators of the muscles depend on their anatomical structure. There are muscles with a feathery structure, as well as fusiform with a parallel arrangement of fibers. Scientists have established. That the first type of muscle is short and can develop great effort. A typical example of this type of muscle is the calf muscle. In turn, the fusiform muscles are usually long enough to perform fast sweeping movements, such as the sartorius muscle.
Types of muscle fibers
The strength indicators of the muscles directly depend on the cross-sectional area of the fibers that make up them. In turn, the rate of contraction will be greater when the fibers are longer. Some of the muscles in the human body are able to contract to half their original length.
All muscles are made up of two types of fibers: slow and fast. The latter are muscles with a feathery structure. Under the same other conditions, they will contract much faster than the first type of fibers. In addition, muscle contractility also depends on other factors. These include the indicator of external load, the strength of the muscle itself and the activity of the central nervous system of a person.
Anatomy of Muscle Movements
The ability of muscles to contract is most often characterized by an absolute strength indicator. It is developed by the entire muscle and is calculated per square centimeter of muscle. Thanks to this, it is possible to compare the indicators of the contractile ability of all muscles, regardless of their length. Let's say the shoulder muscle has an absolute strength of 12.1 kilograms per centimeter square.
The muscles contract due to impulses that come from the central nervous system. Each impulse implies one contraction. The stronger the load, the longer the time elapses from the moment the impulse arrives to the muscle contraction. The higher the external load applied to the muscle, the less it shortens.
Upon reaching the maximum contraction after receiving the impulse, the muscle again goes into a relaxed state and takes on its original length. It should be remembered that this process does not occur instantly, and if a new impulse is given at the moment when the muscle has not returned to its initial position, then the contraction caused by it will be faster and more powerful in comparison with the first contraction.
During training and during normal work of the muscles, tetanic contractions always take place. Their power directly depends on the strength of signals coming from the central nervous system. Even if the muscles do not work, then a certain tension is always present in them, and they contract somewhat, since impulses from the central nervous system continue to flow during the rest period.
For any condition of the muscles, a certain length is characteristic. When there is no external load, then when the physiological state changes, the muscle tries to take on such a length that corresponds to this state.
Learn more about how muscles work in bodybuilding in this video:
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