Poetry In Motion: The Anatomy And Function Of The Shoulder


We use our hands and arms every day without really thinking about how they work, do we not? Did you ever stop to think about how limited that movement we take for granted would be if anything ever happened to your shoulder? The anatomy and function of the shoulder is a biological miracle in itself, and in this article we will show you how it works, as well as the trouble it can get itself into.

Anatomy and Function of the Shoulder

The shoulder is the second most mobile and flexible joint in the human body, the first being the hips. Like the hips, it is considered to be what is known as a ball-and-socket joint. The ball part of it comes from the end of the humerus, the bone that is in the upper portion of our arms, which fits into a socket called the glenoid fossa, which is located on the scapula, also known as the shoulder blade. This arrangement is far more delicate than that found in the hips, which has the ball of the hip bone completely surrounded by the bones of the pelvis, providing far more stability than that which is found in the shoulder.

Ligaments connect the ball and socket construct that makes up the shoulder, and help to provide some stability to it. Naturally forming fluids from within our bodies lubricate it, and keeps friction at a minimum as it moves. The muscles attached to the shoulder blade, like the deltoids, and the muscles attached to the humerus help to move the arms, and control its range of motion.

Another important part of the shoulder construction that keeps everything moving as it should is the rotator cuff. This is a group of four muscles that control the rotation and positioning of the arms. Each of them have a tendon at the end that is attached to the humerus by growing directly into it. If this cuff of muscles becomes torn in some way, or detached, it can seriously limit the movement of the arm until repaired through surgery.

Major Ailments of the Shoulder

In some people, the stability of the shoulder itself is not as strong as it is in others. If the shoulder slips out of its socket on occasion, it is considered to be unstable, and shoulder instability can lead to other problems later on, like dislocation. Some people simply have looser joints than others, leading them to be categorized as being double-jointed, but, over time, recurring dislocations can lead to ligaments or muscles being torn, due to loss of flexibility, and the joint itself may not be fitted back into place as easily as it once could be. Arthritis is also a major concern, because it can cause the joint to swell and cause extreme pain.

A torn or detached rotator cuff can also be a major concern when it comes to the anatomy and function of the shoulder. This is a condition that cannot be simply allowed to heal on its own, not even with physical therapy. A simple tear, depending on where it is located, might not affect motor function, but it will still need to be repaired through surgery. Should the rotator cuff become detached through injury, or normal wear and tear over time, it will have to be repaired through arthroscopic surgery, which will reattach that cuff of muscles, and restores most of the function back to the shoulder and arms. Without it, range of motion, strength, pivoting and positioning of the arms will be extremely limited, and the affected arm will be forever weakened without the cuff being restored.

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