The arm can be divided into the upper arm and the forearm. The elbow is the junction between the upper and lower arm.
Author
Leading Medicine Guide Editors
Article overview
The upper arm
The humerus is the longest bone in the arm. With its rounded head (humeral head), it is part of the shoulder joint. The humerus cartilage, which connects to the humeral shaft at the bottom, lies to the side of the elbow joint.
The upper arm muscles can be divided into the flexor (flexors) and extensor (extensors) groups. The most important upper arm muscles are the forearm flexors (biceps brachii muscle and brachialis muscle) at the front and the forearm extensors (triceps brachii muscle) at the back.
The forearm
The forearm is located between the elbow joint and the carpus and consists of two bones: the radius (radius) and the ulna (ulna). The radius is connected to the carpus via the two very mobile wrists. It is mainly the muscles coming from the forearm that cause the hand to move. Only the slender tendons of the muscles are located directly in the hand.
The elbow
The elbow (cubitus), the junction of the upper arm and forearm, consists of the cubital fossa (cubital fossa) and the elbow joint (articulatio cubiti). In the elbow joint, the humerus (upper arm bone), radius (radius) and ulna (ulna) form three partial joints that are encased in a joint capsule. This capsule is reinforced by three ligaments (inner ligament, outer ligament, annular ligament).
Diseases and injuries to the upper arm, forearm and elbow
Fractures in the forearm area are common. A distinction must be made between an isolated fracture of the radius (radius fracture - the most common fracture of all), the ulna (ulna fracture - rare) and a complete forearm fracture in which both forearm bones are affected (not quite as common as the radius fracture).
Fractures in the upper arm include fractures of the humeral head (humeral head fracture), the less common fracture of the humeral shaft (humeral shaft fracture) and fractures in the lower part of the upper arm.
In the elbow region, elbow fractures, elbow bursitis, dislocations of the elbow joint and Chassaignac's palsy (subluxation of the radial head) can occur. The radial head often slips out of the annular ligament in children, e.g. when an adult suddenly pulls the child's outstretched arm up to hold it when tripping. However, the radial head is also easy to retract.
Tendon sheath inflammation occurs particularly in the wrist area. A torn biceps tendon (biceps tendon rupture) does not always cause severe pain.
