The humerus is the largest bone in the entire upper limb. The upper part of the humerus connects to an area called the glenoid fossa on the scapula or scapula . The lower part of the humerus touches the upper part of the radius and the ulna , which connects the upper arm with the lower arm.
The union of these bones provides a wide range of motion that is possible at the shoulder joint, as well as movement at the elbow joint.
The humerus has two large projections on top of the bone, called the greater and lesser tubercles, that connect to the shoulder blade to provide movement and stability.
The rhythm between the scapula and the humerus is very important for proper shoulder function.
Another important landmark is the anatomical neck, a slightly narrower area just below the tubercles but above the axis, which is the longest part of the bone. This region of the neck is the most commonly fractured part of the humerus due to its width. Unfortunately, a fracture of the humerus at this site can be dangerous for children and adolescents, as it is also the site of the epiphyseal plate or growth plate.
The shoulder joint, which is made up in part of the humerus, is considered a ball joint. This type of joint is the most versatile in the body and allows any degree of movement. Proper anatomy must allow for this movement, which also makes this joint very vulnerable to injury if there is improper movement and effort.
As mentioned, the growth plate is an integral but sensitive part of the humerus. Birth defects, infections, and / or trauma can affect this growth plate, disrupting the growth process. This can lead to shortening or other deformities of the humerus. In such situations, medical intervention can assist with bone lengthening techniques to achieve a more normalized and functional bone appearance.
The head of the humerus is part of the ball-shaped shoulder joint. This area also serves as an attachment point for the muscles that make up the shoulder girdle. This includes the long head of the biceps tendon, as well as the supraspinatus, infraspinatus, teres minor, and subscapularis, which are known as the rotator cuff muscles.
The humerus works with these muscles to raise and lower (also called flexion and extension) the forearm, lift to the side and lower (also called abduction and adduction) the forearm, move the arm in small and large circular motions (also called circumduction) . and rotate in or out (also called inward rotation and outward rotation).
There are also many ligaments in this area, which not only help to strengthen the muscles, but also provide movement to the shoulder joint.
There is also a large network of nerves running through the front of the humerus called the brachial plexus.
This provides sensation and movement not only to all the muscles in the arm, but also to areas of the neck and spinal cord.
Tendinitis or bursitis
This is a common condition in which the tendons that surround the humerus, or the humerus itself, become inflamed and irritated. This may be due to age or overuse, such as when working with repetitive motions or playing sports that require frequent and strong arm movements.
Frozen shoulder is a condition that results from thickening of the shoulder capsule, causing painful movements and significant stiffness. Although it is a connective tissue dysfunction, it occurs just above the head of the humerus, which can lead to degeneration and displacement of the humerus if not treated properly.
Like most large joints, the head of the humerus is prone to osteoarthritis. This condition usually occurs with age and is the result of the wear and tear of the cartilage at the end of the bone. This can cause severe pain with any joint movement.
Each of these conditions can be treated conservatively (that is, without surgery) by a physical therapist, occupational therapist, or physician. Treatment with a doctor may include surgery or your own conservative methods, which generally include injections for pain and inflammation.
As with most fractures, the treatment of humerus fractures follows a protocol to maximize function. Despite the similarities, there are different protocols for the treatment of fractures of the shaft or the distal end of the humerus.
Open and closed cut
Open reduction with internal fixation occurs when doctors need to repair bone fragments with rods, screws, plates, or other equipment. Closed reduction is also performed by a physician in a simple procedure that does not require any surgical incisions. Each of these procedures is usually followed by a bandage or bandage to protect the hand and prevent re-injury, while the patient slowly resumes some of their daily activities.
Rehabilitation protocols will differ depending on the type of fracture, but passive range of motion (where the therapist performs stretching exercises for the patient) is recommended 24 to 48 hours after surgery to avoid loss of motion. About four weeks after surgery, the patient can do light exercises under the supervision of a therapist. The most intense strengthening exercises begin about three months after surgery.
The therapy programs provided by an occupational therapist or physical therapist will vary depending on the deficiencies identified in each individual. These programs generally include splinting when overused and exercises to improve coordination, strength, and range of motion of the shoulder and shoulder joint.
The goal is also to teach the use of equipment to compensate for any loss of function during the healing process and to perform daily activities that may be more difficult after injury and / or surgery.