Anatomy. Human Forearm

The structure of the structure of the lower and upper extremities is the same. In the process of development, the hand ceased to serve as a support for man. Now he can make her complex different movements. Thus, the bony and articular structure of the upper limbs reflects their function, as parts of the body that provide free movement. In this case, freedom of movement is determined by the permissible degree of freedom in the joints.

The upper limb of a person is divided into three segments: the shoulder, forearm and hand. Bones are joined by ligaments and joints, forming links that work like levers.

The structure of the forearm includes bones (ulnar and radial), upper and lower cylindrical joints, as well as the muscles of the posterior and anterior group.

The ulna is located medially (on the side of the little finger), the radial bone is lateral (on the side of the thumb). They are connected by means of the upper and lower cylindrical joints. Their combined action provides rotational movements of the forearm inward and outward. In this case, mobility is peculiar only to the radius bone. It moves (like the movement of the leg of the compass) around the ulna remaining motionless. Lowering below the ulna , the radial bone joins the skeleton of the wrist.

The human forearm has muscles of the posterior and anterior group. The front consists of flexors for the fingers and the hand and the muscles that rotate inwards. In the back group are extensors of the fingers and hands and muscles that rotate outward.

It should be noted that all the diverse and complex movements in the segments of the upper limbs are carried out by a complex of simple movements of different joints.

The human forearm can bend, rotate inward or outward and unbend. In this case, movements are made around the transverse and vertical axis in the elbow joint. Movements are made by four functional groups of muscles.

The movements of flexion are carried out: a round pronator with forearm muscles starting from the humerus (inner epicondyle), biceps arm muscle, brachial muscle, brachial muscle.

The movement of extension is performed by the triceps muscle. It is part of the shoulder and consists of the elbow muscle, the muscles of the forearm, starting from the epicondyle, located laterally in the humerus.

Movement (rotation) inside (pronation) is carried out by a round and square pronator. In this case, the humerus muscle participates (with the opposite pronation of the position).

Movement (rotation) outside (supination) in the human forearm is carried out by the muscle-supinator and the biceps muscle. Rotational movements are made from the pierced position (from the outside).

The muscles included in the human forearm are involved in the movements of the hand and wrist.

Flexion is made by the radial and ulnar flexors of the wrist, the long palmar muscle, the superficial, deep and long flexors of the fingers. It should be noted that the three flexors of the fingers produce simultaneous movement.

The wrist can flex, rotate inward or outward and unbend. It should be noted that the joint mobility is limited in this case. The exception is the carpometacarpal joint of the thumb.

The free movements of all segments of the upper limbs are determined by the permissible degree of freedom in each joint. It should be noted that the development of the muscles of the forearm, in particular, involved in the movements of the hand and fingers, are of great importance in the proper development of the child. Therefore, at an early age, it is necessary to work with them, so that the finger movements correspond to the age of the child. It is proved that correctly developed hand motor skills prevent complications in the development of the speech apparatus.