Shoulder Joint Lab

Task: Write a report

Select three joints.

Shoulder Joint (Ball and Socket)
Elbow Joint (Hinge)
Wrist Joint (Condyloid)

Discuss the description of the movement at each joint action for the ideal performance of the over hand volleyball serve.

Ball and Socket:
When preparing for a volleyball serve, the right shoulder joint is primarily used. The shoulder joint is a third class lever operating on the humorous bone, which is held in place by the clavicle bone and scapula. These three bones make up the Ball and Socket joint which consists of a globular head (humerus) that articulates with the cup-shaped cavity of another bone (the scapula). This joint allows a wider range of movement therefore permitting movements in all directions
around a central axis. Hence this particular joint is found in the shoulder as it is the most mobile joint in the body, which is crucial when preparing and following through with an overhand volleyball serve.
The movements at the shoulder joint are flexion, extension, abduction, adduction, internal and external rotation and circumduction. After the ball is thrown in the air via my left arm, my the right arm above my head involving extension of the shoulder joint. When the ball begins to fall, I further extend my arm to maximise the motion to therefore apply maximum force to the volleyball. This is then closely followed by a quick flexion of the shoulder joint once my shoulder has reached its full extension in order to smack the volley ball over the net (serve the volleyball). As my shoulder flexes the pectoral’s major contracts. The deltoid is also vital to shoulder movement, during my flexion the anterior deltoid will contract, pulling the humorous and therefore my arm towards my chest. These two
muscles are the prime movers in shoulder flexion. The antagonists in shoulder flexion are the Posterior deltoid and latissimus dorsi. These muscles relax to allow me to swing my arm with maximum force once in contact with the ball therefore complete an overhand volleyball serve.

Hinge Joint:
The elbow joint is a Hinge joint, with the distal end of the humerus articulating with the proximal ends of the radius and ulna.
The elbow joint only allows flexion and extension as the movement is possible in one plane only. Also within the elbow joint capsule, the radius articulates with the ulna to form a pivot joint. The radioulnar joint allows pronation and supination of the lower arm which is most useful when performing an over arm volleyball serve. The elbow is again a 3rd class lever in the arm. Operating in conjunction with the shoulder to maximise the force generated in the arm. As the ball is tossed, like the shoulder joint, my elbow moves into a fixed-ready position, moving my elbow into total flexion. As my elbow flexes the biceps contract, pulling the ulna into extension. Although the biceps are only pulling on the ulna, this doesn’t mean the radius isn’t at all involved. The antagonist to the biceps are the triceps which relax during flexion of the elbow joint, allowing my arm to to gain maximum flexion to in turn follow through with extension when my palm comes in contact with the volleyball. As my elbow flexes, my forearm also pivots via the radioulnar joint, allowing my palm to face down (pronation) so that its my palm in contact with the ball rather than the top in my hand. As my palm pronates, the pronator trees contract thus the supinatior muscle relaxes. Because of this, I am able hit the ball with maximum force allowing the ball to fly over the
net.

Condyloid Joint:
In the wrist, or radiocarpal, joint, the condyle is located on the end of the radius bone of the forearm, and it articulates with the cavities of the adjacent carpus bones of the wrist. Bending the wrist forward toward the palm and backward toward the back of the hand represents flexion and extension, respectively, while tilting the wrist joint from side to side, as in waving one’s hand, represents abduction when tilting in the direction of the thumb and adduction when tilting in the direction of the little finger. Additionally, the wrist joint is capable of circumduction, through these two planes. As the ball is tossed, like the shoulder and elbow joint, my wrist moves into a ready position waiting for that contact with the ball. My wrist joint hyperextends when waiting for the ball, as my wrist does this the wrist extensors contract. The wrsit extensors are the prime mover/agonist as my wrist hyperextends in a ready position waiting for the serve, pulling the carpus bones into extension. As the wrist extendors contract, the wrist flexors relax allowing for my wrist to extend in my ready position. As my wrsit comes down to hit the ball, the wrist joints flex thus the wrist flexors are the prime movers/agonist. The wrist flexors then contract pulling the radius into flexion. The wrist extensors relax during this movement.