Shoulder pain is one of the most common complaints often seen in primary care clinics. In fact, it is the third most common musculoskeletal complaint after neck pain and back pain.
The shoulder is made up of several joints along with muscles and tendons. It is the most mobile joint in the body and is capable of a wide range of motion. Since so many different structures are involved in the shoulder, it is also vulnerable to a wide range of problems. Shoulder impingement syndrome is a common issue.
What is shoulder impingement syndrome?
Your arm is held in place in your shoulder socket by a group of muscles and tendons called the rotator cuff. Between the rotator cuff and acromion (the bone right on top of your shoulder) is a lubricating sac known as bursa which helps the rotator cuff tendons slide smoothly and allow the arm to move freely.
When the rotator cuff is injured, it can lead to swelling. This swelling can increase pressure within the muscles and impede the flow of blood in the area, resulting in pain. The pain is further aggravated by actions such as reaching up overhead or behind the back. As the arm is raised to shoulder height, it narrows the space between the rotator cuff and the acromion. The bone can then "impinge" on the tendons and bursa, causing pain. This situation is called shoulder impingement syndrome. Bone spurs growing from the shoulder blade, calcium deposits within the rotator cuff tendon, and poor posture can also cause impingement. The typical symptoms include experiencing pain while reaching up behind the back or overhead, and the shoulder muscles feeling weak.
Causes of shoulder impingement
Shoulder impingement may be caused due to several reasons. Some of them include:
Overuse
When the shoulder is overused, especially in ways that cause the arm to stay overhead for a long time, it may lead to inflammation and thickening of the bursa, leading to shoulder impingement. Swimming, tennis, and basketball are activities where the shoulder tends to get overused. Other examples include carpentry or handling of machines which require pulling of overhead levers continuously.
Trauma
If you happen to fall on an outstretched hand, it can cause a tear in the rotary cuff leading to impingement.
Variation in the shape of acromion
When there are variations in the shape of the acromion, possibly due to growth of bony spurs, it can result in impingement.
Aging
As you age, the wear and tear of the rotator cuff can cause swelling shoulder impingement.
Poor mechanics
Weakness of the muscles in and around the shoulder can cause poor posture and arm movement. This can result in impingement.
Symptoms of shoulder impingement
Some of the common symptoms of shoulder impingement include:
- Pain in the affected shoulder and difficulty in movement.
- Inability to reach overhead or at the back.
- Difficulty sleeping, especially when sleeping on the side of the affected shoulder.
- A popping and grinding sensation while moving the shoulder.
Treatment of shoulder impingement
If the impingement is only minor, testing the shoulder muscles may be sufficient. Your doctor will advise you how long you should rest. It is important to ensure that the shoulder does not remain inactive because it may gradually stiffen up. After a period of rest, you should start with arm exercises to strengthen the muscles.
Ice packs applied to the shoulder for about 20 min several times a day can help reduce pain. Instead of ice cubes, you may also wrap a bag of frozen veggies in a towel and use that instead.
While oral anti-inflammatory medicines and pain killers will help ease the pain, it is important to treat the underlying condition rather than the symptoms alone. Doctors usually prescribe the intake of ibuprofen and naproxen to ease the pain. If the symptoms do not ease up even after taking medications, your healthcare practitioner may use a cortisone injection - a potent anti-inflammatory remedy used only in very severe cases. If everything fails, an MRI may be suggested to identify rotator cuff tear which is then treated via surgery.