The humerus is the thickest bone of the upper extremity, forming the glenoid joint with the scapula proximally and the elbow joint with the radius and ulna distally. The main anatomical structures on the humerus are the humeral head, humeral stem, greater and lesser tuberosity, radial nerve groove, distal medial epicondyle and lateral epicondyle.
1. Humerus head: connects to the scapula to form the shoulder joint and maintains joint mobility.
2. Humerus stem: the main body of the humerus, the distal end is the starting point of the humerus muscle, which plays a role in flexing the elbow joint.
3. Greater tuberosity and lesser tuberosity: the greater tuberosity is the stopping point of supraspinatus, infraspinatus and teres minor, and the lesser tuberosity is the stopping point of teres major and subscapularis, and these muscle groups play a role in moving the shoulder joint, such as adduction, abduction and rotation.
4. Radial nerve sulcus: there is radial nerve sulcus in the middle and lower 1/3 of humerus, radial nerve passes through from then on, and innervates the movement and sensation of forearm and hand.
5. Distal medial epicondyle and lateral epicondyle: they are the starting point of forearm flexor and extensor muscles, mainly affecting forearm flexion and extension.
The humerus is an important bone in the human body. Once abnormalities are detected, you should go to the hospital in time and be diagnosed and treated under the guidance of a professional doctor.