Proper functioning of the radius is essential for performing any day-to-day activity with our hand, from holding something, balancing with the arm, throwing something, writing, typing, using the phone etc.
The radial tuberosity , a bony projection below the neck [3] Surfaces and Articulations:. A concave articular surface on top of the head for the capitulum of the humerus elbow humeroradial joint [5]. A smooth circumference of the head articulating with the radial notch of the ulna proximal radio-ulnar joint [3] 2. There are several landmarks on the radial shaft for the origin and insertion of various tendons [6] Borders.
Anterior; 2. Posterior; 3. Medial or interosseous, the sharpest border where the interosseous membrane connects. Lateral [3] 3. Lower End Distal Radius Landmarks:. The ulnar notch on the medial side [1] Surfaces and Articulations:.
The concave surface of the ulnar notch articulating with the ulnar head distal radio-ulnar joint [2]. A lateral triangular area on the distal or inferior surface forming joints with the carpal bones scaphoid and lunate wrist joint [2] Radius Bone Muscle Attachments Name of Muscle Insertion at Radius Biceps brachii The rough posterior surface of the radial tuberosity [3] Pronator teres Lateral surface of the shaft Pronator quadratus Medial surface of the shaft Supinator Laterally on the shaft, covering one-third of the proximal radius both origin and insertion Name of Muscle Origin at Radius Flexor digitorum superficialis Medial surface of the shaft Flexor pollicis longus Medial surface of the shaft Abductor pollicis longus Anterior surface of the shaft [5] There is a layer of hyaline cartilage covering both the proximal and distal ends of the radius.
This makes the articular surfaces smoother so there is less friction in the joints during arm movements. It also works as a shock absorbent to reduce stress on the elbow and wrist joints from any impact [1]. The anterior part of the radial tuberosity is covered in a synovial bursa, called the radial bursa, to keep it separated from the biceps tendons of the biceps brachii muscle during movements [3].
When the radial tuberosity is facing anteriorly or facing you , the styloid process of the radius should be on the same side as the thumb. Holding the bone in this manner helps with determining whether it is the left or right radius. The radius is considered the most commonly fractured bone in the human body, with distal radius fractures being the most common form of radial fracture [9]. Radial head dislocation is another common injury associated with the bone [10].
The bone may also be affected by arthritis of the wrist or elbow joints. Though the ulna is longer than the radius, the latter is comparatively thicker throughout its length, especially in the shaft area [8]. Your email address will not be published.
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The radius is the thicker and shorter of the two long bones in the forearm. It is located on the lateral side of the forearm parallel to the ulna in anatomical position with arms hanging at the sides of the body, palms facing forward between the thumb and the elbow. The radius and ulna pivot around one another to allow rotation of the wrist.
Together, along with the humerus, they create the elbow joint. The radius is often thought of as the larger of the two long bones in the forearm because it is thicker than the ulna at the wrist, but it is thinner at the elbow. The ulna is longer than the radius by about an inch in most people, but lengths vary considerably.
Of the two forearm bones, the radius is more likely to suffer a fracture than the ulna. Men and women have similar instances of radius fractures until the mid 40s when they become much more frequent in women than in men.
The radius is a long bone, one of the four types of bone in the body. A long bone is a dense, strong bone characterized as being longer than it is wide. The shaft is known as the diaphysis and the end of a long bone is called an epiphysis. The diaphysis is hollow, with space inside called the medullary cavity. The medullary cavity contains bone marrow. The radius is between 8 to It averages 9. The proximal epiphysis the end at the elbow is about half as wide.
As described above, the radius is a typical long bone with dense, hard bone along the shaft diaphysis. The ends of the radius have spongy bone that hardens with age. The radius is located in the forearm, the part of the arm between the elbow and the wrist. In the anatomical position with the arms straight and palms held forward at the level of the hips, the radius is positioned parallel and lateral to outside of the ulna. In resting position, such as with your hands on a keyboard, the distal far ends of the radius and ulna cross with the radius lying on top of the ulna.
The proximal end of the radius makes up the lateral outer edge of the elbow joint at the distal end of the humerus. The distal end of the radius attaches to the wrist just before the thumb. The pivoting motion of the radius and ulna allow for rotation of the wrist at the distal radioulnar joint. The radius provides stability for the hinge joint at the elbow and allows for motion at the radiohumeral joint, but the ulna and humerus do most of the work there.
There is some movement between the proximal ends of the radius and the ulna called the proximal radioulnar joint. The radius and ulna are connected by a sheet of thick fibrous tissue called the interosseous ligament or the interosseous membrane. A smaller ligament connects the proximal ends of the radius and ulna. It is known as the oblique cord or the oblique ligament and its fibers run in the opposite direction of the interosseous ligament.
In some cases, the radius bone may be short, poorly developed, or absent. One variation seen in the anatomy of the radius is proximal radio-ulnar synostosis, in which the bones of the radius and ulna are fused, usually in the proximal third the third closest to the elbow. This condition can be congenital, but it can rarely occur after trauma to the bones, such as a dislocation. The radius allows for movement of the arms and especially provides for the full range of motion of the hand and wrist.
When crawling, the radius also can help to provide mobility. The radius provides bodyweight support when the arms are used during crawling and lifting the weight of the body, such as during pushups. The radius has seven muscle insertion points for the supinator, biceps brachii, flexor digitorum superficialis, pronator teres, flexor pollicis longus, brachioradialis, and pronator quadratus.
The most common medical condition of the radius is a fracture. The radius, while shorter and a bit thicker than the ulna, is fractured more often. It would seem that the longer ulna would have more force applied during falls or other mechanisms of injury.
However, it is the radius that is one of the most common fractures of all age groups. Weight distribution during a ground-level fall where the patient breaks the fall with hands down puts most of the pressure on the radius.
It is possible to break only the radius, only the ulna, or both bones of the forearm. Distal radial fractures are the most common type of radius bone fractures. Elderly patients and pediatric patients are at more risk than young adult patients during a fall onto an outstretched hand sometimes called a FOOSH injury. Elderly patients are at risk for radial head fractures, which refers to the proximal end of the radius that makes up part of the elbow.
Pediatric patients are more likely to have noncomplete fractures, often called greenstick fractures , due to the flexible nature of immature bone tissue. Pre-adolescent patients are also at risk of damaging the epiphyseal plate growth plate. Damage to the growth plate can lead to long-term deformity.
Regardless of the type or severity of a radial fracture, symptoms typical of all long bone fractures are to be expected. Pain is the most common symptom of any fracture and is the only symptom that can be considered universal. Pain after a fall onto an outstretched hand can lead to pain in the wrist, forearm, or elbow. All of these could indicate a radius fracture. Every other sign or symptom of a fracture may or may not be present.
Other signs and symptoms of a fracture include deformity, tenderness, crepitus grinding feeling or sound from broken bone ends rubbing together , swelling, bruising, and loss of function or feeling. Radial fractures are not life-threatening and do not require an ambulance or even a visit to the emergency department.
Often, a trip to the doctor can start the process of diagnosing and treating a radial fracture as long as the doctor is able to arrange for an X-ray.
Treatment and rehabilitation of the radius after a fracture depends on the severity and location of the injury. Treatment begins by immobilizing the fracture site. The bone ends have to be placed back into the correct anatomical position called reduction to promote proper healing. If the bone isn't placed into the correct position, new bone growth could result in permanent deformity. The type of reduction and immobilization needed is based on the type and location of the fracture.
Severe fractures may require surgical immobilization, while minor fractures might be able to be immobilized through manipulation and a cast or splint. After immobilization, long-term rehabilitation includes physical therapy. A physical therapist will be able to teach the patient stretching and strengthening exercises that put the right amount of pressure on the right areas following a fracture.
Physical therapy may also be necessary for the shoulder due to the immobilization of the injured arm. Not being able to use the forearm means the patient likely isn't moving her shoulder much either. Surgical repair or reduction of severe fractures may take more than one surgery to fully repair the injury. Each surgery requires a healing period and the patient may need physical therapy to return to pre-surgical function.
It might be several months between surgical procedures for some injuries, requiring a rehabilitation process after each procedure.
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