All physical actions that a person performs are performed thanks to the muscles. All of them are divided into several groups and are called synergists, agonists, antagonists, pronators, arch supports. Muscles make movements in all joints, hold the body in an upright position, provide movement of the arms and legs.
What muscles are synergists, and which agonists and antagonists can be understood if we recall what functions they perform and where they are located.
All muscles in their structure can be divided into 2 groups: smooth and striated. The first group is involuntary musculature. It cannot be reduced by the will of consciousness. This group of muscles lines the walls of blood vessels, internal organs, and skin.
The second group is voluntary musculature. It consists of over 600 muscles, and they can contract by the will of consciousness. These include the superficial muscles of the human body (except the cardiac).
Functions
According to the functions performed, all muscles perform the following types of movements: flexion, extension, abduction, adduction, pronation, supination.
Each action is provided by the work of several muscle fibers. They can interact with each other and consistently carry out certain work.
Almost all muscles are attached to one or more joints. Thanks to this property, their movement is ensured.
Typically, the flexors are located in front (these are biceps, rectus abdominis muscle, delta), and the extensors are posterior (triceps, extensors of the back, gluteus maximus). The exception is the knee and ankle joints. Here the muscles are located on the contrary, quadriceps in front, hip biceps in the back.
The muscles that provide the abduction movement are located outside the joint (middle bundle of the delta, middle gluteus), and the adduction is located inside (the adductors of the thigh).
The rotation is carried out by muscles located diagonally or across from the vertical axis.
Interaction
No physical exercise or action is performed in isolation by a single muscle. Several muscle fibers are always involved in the work.
Several groups are distinguished depending on the type of interaction: synergistic muscles, agonists, antagonists. Rotation is provided by pronators (inward rotation) and arch support (outward).
If several muscles are involved in the movement and they perform an action together (for example, flexion), then they are called agonist muscles.
The muscles involved in the opposite action are called antagonists.
Synergistic muscles are individual muscles that perform a joint action with others in one specific movement.
Consider an example. Synergistic muscles are involved in traction. Some of them work together and pull in one direction, while others make another movement, stabilize traction in the opposite direction.
In work, antagonist muscles and synergists do not interfere with each other. Movement takes place through concerted action.
To understand which muscles are agonists and which are antagonists, we need to recall their main groups.
Muscles of the human body
The whole human body can be divided into several groups. These are the muscles of the trunk, head, upper and lower extremities. They can be arbitrarily reduced by performing an action.
The body can be divided into muscles:
- necks - participate in the movement of the head;
- breasts - pectoralis major and minor, intercostal muscles;
- abdomen - straight, external and internal oblique;
- backs - trapezoidal, widest.
It is worth noting another muscle of the body - the diaphragm. She divides the chest and abdominal cavities, participates in breathing.
The muscles of the upper limb are biceps and triceps.
Muscles of the lower extremity - quadriceps, biceps of the thigh.
These muscles are far from all, but only the largest. With their help, you can understand the mechanism of work of agonists and antagonists.
Antagonists
This group includes:
- biceps - triceps;
- chest - back;
- hip biceps - quadriceps;
- the muscle that straightens the spine is the rectus abdominis muscle.
In these pairs, one of the groups performs a flexion movement, the second - extension. Chest - back - multi-joint movement, bench press and traction.
Synergists
This group includes:
- pull-ups - latissimus muscle, biceps;
- push-ups - pectoralis major, triceps;
- push-ups on the uneven bars - pectoralis major, anterior bundle of the deltoid muscle, triceps;
- Squats - quadriceps, gluteus maximus, thigh biceps.
All synergistic muscles perform one movement, helping each other.
Location
Agonists and antagonists are usually located on opposite sides of the joint (biceps and triceps). Flexion of the shoulder when the biceps (agonist) is working can lead to relaxation of the triceps (antagonist). This phenomenon is called mutual inhibition.
There is such a thing as joint compression, when antagonists are compressed in one movement. Joint compression occurs in the squat, when the extensors of the back and abs are simultaneously reduced.
Synergist muscles are located in the same place as the agonists, or somewhere nearby. When performing the movement help them.
Pronators, arch supports
Rotation inward in the shoulder joint is provided by a large pectoral, latitudinal, subscapular and large round.
Outward rotation in the shoulder joint occurs due to the infraspinatus and the small round.
Life application
Knowledge of the characteristics of the human musculature is widely used in bodybuilding. For example, when building a training program using a technique such as a super series, synergistic muscles are sometimes used. Examples: pulling up and bending for biceps, bench press and extension of the forearm. The muscles involved in the work are co-directed.
But most often, training is used, in which antagonists participate. For example, triceps and biceps, chest and back, quadriceps and hip biceps.
Typically, antagonist training occurs simultaneously. This approach provides uniform muscle growth and development.
Training will be most effective if you know which muscle groups are involved in a particular exercise. The experience of athletes proves the benefit of training in which antagonists or synergistic muscles work simultaneously. Examples are the outstanding bodybuilder Arnold Schwarzenegger and others.