Shoulder joint is the most flexible joint in our entire body! It is also one of the more complex joints, since it is build up of not two but three bones:
- Humerus – upper arm bone
- Scapula – shoulder blade, and
- Clavicle – collarbone
This complexity is really a double edged sword – on one hand it is responsible for the incredible flexibility of this joint, on the other hand it is making it unstable. As a result of this instability, shoulder joint is often a place of various injuries – fractures, dislocation, strains, sprains, rotator cuff tears and arthritis.
Before we cover these injuries in more detail, I would like to take a step back and go over the anatomy of the shoulder joint so we can get better acquainted with it.
Shoulder Joint Anatomy
As I`ve mentioned before, shoulder joint is built up of three bones and two joints – glenohumeral and acromioclavicular.
Glenohumeral joint is a joint between the humerus and the shoulder blade, and this is where all the mobility takes place!
This is a “ball and socket" joint, where the ball-shaped surface of the humerus fits into the cup-like surface on the shoulder blade. Ball and socket joins are the most flexible joint in the human body; they allow a wide range of motion but are also susceptible to injury and wear and tear.
This is a joint between the acromion (part of the scapula) and the collar bone. Even though this joint is not as flexible as the previous one, it still plays a key role in the overall stability of the shoulder joint and gives it additional flexibility.
Most Common Causes Of Shoulder Pain
Shoulder joint is the most flexible joint in our body but this flexibility comes at a high price. there are a lot of causes of shoulder injuries There are a number of different causes of problems and pains in the shoulder joint, but today we will be covering the most common three:
Even though shoulder fractures are more common in older individuals, they can affect younger generations as well. Fractures in this area usually involve humerus, clavicle and shoulder blade, cause severe pain, bruising and swelling of the shoulder and can take a long time to heal.
Shoulder fractures usually involve the three bones we mentioned earlier:
- Clavicle fracture – this is a very common fracture in people of all ages. It is usually caused by a direct blow to the bone. Most common symptoms of a fracture include collarbone pain, inability to lift the arm, shoulder instability, bruising or swelling.
- Shoulder blade fracture – shoulder blade fracture are not that common, but they can sometimes occur as a result of a high impact collision, such as a motor vehicle accident. Most common symptoms of these fractures are swelling, bruising and intense pain when lifting or moving your arm.
- Humerus fracture – fractures to the upper arm bone are usually caused by a direct blow. We can divide the humerus fractures into three groups – proximal, mid-shaft and distal humerus fractures. Symptoms involve pain, swelling and limited mobility of the arm.
2. Tendon Tears
Tendon connect muscles to the bone and are usually quite strong and flexible, but they can weaken due to wear and tear. In addition to wear and tear, a tendon can also become weaker as a result of:
- Natural aging process
- Degenerative process in the tendon itself or
- A sudden severe trauma
We can divide tendon tears into two groups: complete and partial. Partial tendon tears are easier to treat as opposed to complete tears where tendon is pulled away from its attachment on the bone.
Shoulder pain can also be caused by arthritis and, even though there are many types of arthritis, the most common one that affects the shoulder joint is osteoarthritis. This type of arthritis is usually related to some sport activities where shoulder joint is under a lot of strain, but it can also develop in individuals who don’t play sports but lead an active life and use their arms excessively.
Most common symptoms of osteoarthritis in the shoulder are:
- Stiffness and
- Pain which intensifies over time
It is also not uncommon for a person with arthritis to have a limited range of motion. This usually happens because certain movements cause a lot of pain so the person avoids them, which leads to stiffness, tightness and ultimately reduced mobility in the joint.
Author`s bio: Hi everyone, my name is Igor. I enjoy talking about health, writing about health and being healthy! I also run my own little back pain blog, where I cover many different health topics but mainly focus on musculoskeletal problems; you can stop by at any time at https://helpyourback.org/.