Understanding a Shoulder Injury – Part 2
In Part 1 of Understanding a Shoulder Injury we discussed what structures in the shoulder joint can become injured. In Part 2 we will discuss the structures that surround the shoulder joint.
Muscles
The shoulder relies on many muscles to function properly. These include the muscles that stabilize and move the shoulder blade, the muscles that stabilize the arm bone within the shoulder joint (also known as the Rotator Cuff muscles) and the muscles that move the arm.
Any of these muscles can become injured through a sprain, strain or tear and therefore cause pain and/or the shoulder to function improperly.
One particular muscle in the shoulder that is especially susceptible to injury is the Supraspintus. It is one of the Rotator Cuff muscles.
It is a small muscle that travels from above the bony protrusion (or spine) of the shoulder blade, through a tunnel of bone and ligaments and attaches to the arm bone.
It is susceptible to injury when the arm bone doesn’t rotate precisely within the shoulder joint. This excess movement can cause pinching of the muscle between the arm bone and the shoulder blade. This is what is commonly referred to as Shoulder Impingement.
Tendonitis
A simple way to think of a muscle is a spring attached to a rope. The spring represents the muscle belly; this is where the shortening, lengthening and production of force comes from.
The tendon is more like the rope. A muscle will turn into tendon prior to attaching into a bone.
The tendon is responsible for transferring the force produced by the muscle belly to the bones for either movement or stability.
Tendonitis refers to inflammation of the tendon. In other words something is irritating the tendon causing it to swell and be painful.
Bursitis
A bursa is a small fluid filled sac that typically lies between a tendon and the bone. Its purpose is to prevent the tendon rubbing directly on the bone.
It too can become irritated, inflamed, and painful.
That concludes the two posts about Understanding a Shoulder Injury. If you have further questions please feel free to leave a comment.
