Sandwiched between the humerus and the forearm, the elbow joint is a simple hinge joint that only allows two movements, namely extension and flexion. You may think that this is a disadvantage but the elbow joint, due to its simplicity, is a very stable joint.Credit: http://medicalpicturesinfo.com/elbow-joint/
The Elbow Joint
The elbow joint is made up of two separate articulations together with the humerus; the humeroulnar and the radiohumeral joints. Both of the joints are synovial type, hinge variation. As stated earlier, the movements offered by the elbow joints are constrained to extension and flexion only. Do remember that the C-shaped, line with articular cartilage, trochlear notch of the ulna rotates around the pulley-shaped trochlea of the humerus during movements. To stabilize the elbow joint, the upper part of the trochlear notch articulates with the olecranon fossa of the humerus. During movement, specifically during flexion, the coronoid process of the ulna is connected to the coronoid fossa of the humerus. To help hold in place the joint capsule, the ligaments of the elbow joint, more specifically the radial and ulnar collateral ligaments help in reinforcing it.
Another view of the elbow joint reveals that it is made up of the three bones, converging in a common point. These bones are the humerus and the two bones of the forearm, the radius and the ulna. The joint between the radius and the ulna which is the radioulnar joint allows the radial head to pivot within the radial head of the ulna. This is due to the wide base of the humerus. The ulna, however, cannot pivot around anything due to the shape of the humeroulnar joint.Credit: http://wn.com/radioulnar_joint
The proximal radioulnar joint is not considered part of the elbow joint but due to the reason that its synovial cavity and joint capsule is continuous with that of the elbow joint it is therefore important to mention when tackling about the elbow joint. Furthermore, it is also secured by the collateral ligaments of both the radius and the ulna.
With much thanks to the annular ligament, our elbow remains in place even when the hand is pulled away from the shoulder. It surrounds and secures the head and the neck of the radius and resists its displacement. The joint capsule and the radial collateral ligament reinforce the retaining function of the annular ligament.Credit: http://msjensen.cehd.umn.edu/webanatomy/muscular/musc_skel_arm_1_answers.htm
Of course the elbow joint does not move on its own. It is helped by a number of muscles that cross the joint and assists the elbow in performing its task and also during movement. As you may have already known, the elbow joint is only capable of doing extension and flexion movement and one of the muscles that assist it is the biceps brachii. This muscle originates from the shoulder blade and connects to the radius which helps it in movement regarding flexion action. The triceps brachii arises from the scapula and the humerus then connects to the olecranon and is responsible for movement regarding extension of the elbow. The strongest of all muscles in the elbow when talking in relation to the flexion movement is the brachialis muscle.Credit: http://abfitt.blogspot.com/2010_03_01_archive.html
There are many ways to strengthen the elbow joint as well as there are many ways that can cause injury to it. If you think about it hard enough, you will notice that the elbow joint is one of the joint that’s used most often. It aids us in doing simple task down to performing complex actions.