Movement of the forearm
Movements of various parts of the body is mainly controlled by the group of muscles located around the parts of the body and crossing the joints that hold the part of the body and these group of muscles are usually supplied by nerves that coordinate the activities of those muscles and the movements that tend to occur at such region. Depending on the types of movements that usually occur at the part of the body, the group of muscle around the region usually, function to move the body at an opposite direction. Those muscles are usually located to run across the joints of the region so as to be able to move the part of the body over the joint in the region.
In this situation whereby the forearm has it controlling joints as the elbow and the elbow could be considered as a hinge joint, hence those groups of muscle then work against one another to achieve their task of moving the forearm. Those muscles which are the triceps and biceps tend to act in opposite direction over the elbow to achieve the movement of the joint. The triceps which are located at the posterior aspect of the arm and run across the elbow is known as the extensor of the elbow joint because when it contracts it tend to extend the joint by straightening the arm. The bicep is located in front of the arm and also run across the elbow to antagonize the actions of the triceps whenever it contracts.
The results of the nervous stimulation of both biceps and triceps muscle results in their contraction. The results of this contraction which tend to reduce their length, automatically results in the movement of the bones of the joints. The ulna and radius bones that form the radioulnar bone of the forearm. Those are the two bones that are moved when elbow joint is acted upon by those muscles. The simple mechanism of extension of forearm occur when triceps contract while opposite action of reduction or flexion occur when biceps contracts.
Bibliography
ASSH 2010.Forearm movement. Joints. [Online] Available at: http: [Accessed 11 May, 2011]
