Bones in the Arm

By Amelia Son, PTA

Bones in the Arm

Bones in the arm

Image of the anatomy of the arm

There are three bones in your arm.  The upper arm is made up of the humerus bone. The forearm is made up of the ulna and the radius.  These three bones meet to form the elbow joint. The radius and ulna join the hand to make the wrist joint, which is known as the carpus.

While it is easy to note that the humerus runs down the arm from the shoulder to the elbow, the radius and ulnar are specific to either the pinky or thumb side of the wrist.  The Radius runs from the elbow joint to the wrist’s thumb side and the ulna from the elbow to the pinky side of the wrist.


Bone fractures are common in the arms and are usually short-term injuries.  The most commonly occur from high-impact collisions such as falls, sports injuries, and automobile accidents.  The most common broken bones in the arm are the forearm bones, the radius, and the ulna.

Complicated fractures that have multiple breaks may need surgical intervention. The forearm bones are cast in the proper position to heal a simple fracture.  The forearm bone is made up of collagen and is strong but flexible.  This is how it can take so much force and pressure daily.

This strength is important, considering that most people tend to throw their arms out in front of them to protect them from a fall or accident.  The injury is referred to as FOOSH or falling on an outstretched hand.  Hence the reasons for fractured forearms and, in some cases, shoulder injuries or even a broken collar bone.

Jacksonville Orthopaedic Institute knows the importance of keeping arms strong and mobile for everyday life. Our physical and occupational therapists are here to rehab your arm back to functional status.

Please do not hesitate to call JOI for your medical needs. Further, we have surgeons who can help diagnose your tear and therapy staff, waiting to help rehab you back to full health! Please call JOI-2000 or click the banner below to schedule with one of our specialists.

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Written by: Amelia Son, PTA

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