Pain and tenderness in the upper arm often results from overstretching or overusing one of the muscles running from the elbow to the shoulder. The humerus, a large bone in the upper arm, joins the scapula at the shoulder joint, and at its lower end, forms part of the elbow joint. Sudden falls are a common cause of injury, since a person tends to extend the arm automatically to break a fall; the arm then bears the full weight of the body, often resulting in a fracture, dislocation, strain or sprain causing pain in the upper arm.
Tendonitis
The biceps, the main muscle located at the front of the upper arm, also contains nerves that run from the shoulder to the wrist. Lengthy or repeated contraction of the biceps, which occurs in weightlifting, may cause pain and inflammation called tendonitis and occasionally a rupture of the muscle.
The triceps, the large muscle at the back of the upper arm, can also become overextended or overstretched causing pain and inflammation. According to the American Academy of Orthopaedic Surgeons, injuries to the upper arm are often the result over-extending the arm during exercise such as swimming, tennis and baseball, which require repetitive overhead movement. Sudden forced straightening of the elbow, as when serving in tennis, may strain the triceps as well.
Fracture
Sports injuries that affect the humerus include fractures and dislocations of the shoulder joint between the humerus and the scapula. According to the American Academy of Orthopaedic Surgeons, ligaments, muscles and tendons as well as the actual shape of the bone is what holds the elbow together. When any one of these structures is fractured, torn or inflamed, pain often results. A fracture at the upper end of the humerus usually requires placing the arm in a sling for several weeks. A fracture at the lower end of the humerus may require a plaster cast. Depending on the type and location of the fracture, surgery may also be required.
Dislocated Elbow
Dislocation of the elbow requires immediate medical attention. According to MayoClinic.com, a dislocated elbow typically happens when a person lands on an outstretched hand as he tries to break a fall. It can also happen during contact sports such as football or activities that can lead to a fall, such as bicycling. After confirming the dislocation through X-rays, the doctor manipulates the bones back into position and puts the elbow in a cast or sling to encourage healing.
Bursitis
Bursitis is inflammation of a fluid-filled sac called the bursa, which cushions the bones, muscles and tendons in the extremities. According to the American College of Rheumatology, bursitis can be extremely painful and commonly occurs in individuals who participate in sports, but can also occur in individuals with rheumatoid arthritis, gout, diabetes and thyroid disease. In some cases, a physician will drain the excess fluid from the bursa, inject a corticosteroid drug and tape the elbow. A physician may also recommend resting the arm for several days until the pain and inflammation subside.
