20 December 2010
While the elbow doesn’t have the most extreme range of motion, it is still an extremely flexible joint, and works together with other joints of the upper extremities to perform tasks such as lifting and bringing the hand high enough for one to feed themselves.
The elbow joint is considered a “hinge” joint, since it moves like a hinge. The elbow has a specific up and down motion with very little rotation involved. The elbow is made up of three main bones, the humerus, ulna and radius. The humerus is the bone located in the upper part of the extremity, while the radius and ulna make up the two forearm bones – the radius being the smaller of the two bones and located on the outside of the forearm.
There are three specific joints at the elbow, the humeroulnar joint, the humeroradial joint, and the proximal radioulna joint. The humeroulnar joint is the one that is responsible for the “hinge-action” of the elbow – it gives the elbow the ability to bend. The second, the humeroradial joint assists with the range of motion, but is specifically responsible for allowing the pivoting motion of the arm – the ability to have the palm face up or face down. Lastly, the proximal radioulna joint is what allows the small range of pivoting the elbow is able to perform – specifically the side to side action one would do if waving dramatically.
As with any other joint, there are ligaments that make assist in the movements and range of motion of the elbow. Three ligaments make up the anatomy of the elbow – the medial collateral ligament, the lateral collateral ligament and the annular ligament. Each of these ligaments play an important role in aiding in the flexing, mobility and range of motion of the elbow, and are the structures that connect the bones to other bones.
There is also a group of muscles that support and help with the function of the elbow. Commonly known muscles are the biceps and triceps, although there are many other muscles that are associated with elbow movement and range of motion.
Common elbow injuries include tennis elbow and golfer’s elbow. These injuries come from repetitive motion and overuse of the elbow joint, commonly seen in those who play tennis or golf, hence the name. However, these injuries can occur in those who do not participate in those sports, and can merely be due to overuse and repetitive activities.
References:
eOrthopod website at www.eorthopod.com
