What is the difference between flexion and extension?
In anatomy, flexion and extension are two contradictory movements that can make muscles about the joint. Flexion is a movement in which the angle of the connected joint decreases, as in the bending of the elbow so that the forearm is brought towards the upper arm. Extension is a movement that increases the joint angle, as with elbow straightening. Both occur in a single, front plane of movement, known as the sagittal plane. Flexion and extension can be performed on several types of joints and are initiated by many muscles of the body. In the anatomical position, the body is upright with arms on the sides and palms facing forward. Any movement that occurs in the front direction backwards due to the anatomical position, such as when lifting and reducing the foot directly in front of the body, occurs in the sagittal. In fact, flexion and extension are the only movements that occur in the sagittal plane, although flexion is not always in the direction of the direction and the extension is not always in the direction of the back. For example, the knee bends back while the elbow bends forward.
While many joints of the body can produce movements on multiple planes, some only allow flexion and extension, and therefore only bend and straightened in the sagittal plane. Examples of these joints, called joint joints, are knee and elbow. Flexion occurs on the knee when the knee is bent, while the extension is an act of knee straightening; The same applies to the elbow, although they occur in opposite directions. Other examples of joint joints performing only flexion and extension are interphalangal joints inside the fingers and fingers.
Most joints that are able to bend and expanding movements. The joints of the shoulder and hip can be bent and stretched and also kidnapped, including lifting the limb to the side from the body; an addition that involves drawing a limb to the side back to the body; bypassed, which includes the twisting of the limb; and turned, involving the limb rotation from side to side. On the neck can beThe head bent, bring the chin towards the chest and, on the contrary, extend, tilt the chin up, as well as the kidnapped, manuals, surrounded and rotated. Even intervertebral joints of the spine are able to bend and extend at the segment level, with flexion causing the trunk bend forward and the extension causes the trunk to strain. These are also capable of rotation and movement known as side flexion or side bending.
Flexes and extensions are also differentiated muscles that can produce them. In any joint, flexion is initiated by a muscle or a group of muscles called an agonist and resisted by a contradictory muscle or a group of muscles called an antagonist. The same applies to extension, only the role of muscles is perverted. For example, in the elbow joint, the muscles of the biceps brachii on the front of the upper arm creates flexi while it is against the muscle of the triceps on the back of the arm, which must extend to tighten the biceps. On the contrary, triceps is an agonist during the extension and closes the elbow, burdenMCO biceps is extended in opposition.