Have you ever painted the house, washed the car, did some lap swimming, played tennis, and suddenly felt a pain at the front of your shoulder later that day? Well this pain, which doesn’t always come about with these activities, is most likely a condition, which you may or may not have heard about, called shoulder impingement.
This pain may have subsided by the next day, sometimes within a few weeks, but in other situations, may last up to months if gone untreated. What impingement refers to is the compression/pinching of the rotator cuff or biceps tendons at the shoulder joint between the head of the humerus (upper arm bone) and the acromion (a.k.a. roof of the shoulder joint). Another structure that can be impinged is the subacromial bursa, which would result in a condition called subacromial bursitis. There are other forms of impingement but this is the most common method.
What the above activities have in common are repetitive motions in an overhead position. When the arm goes overhead the head of the humerus glides upward and pinches the rotator cuff tendons into the underside of the acromion. If you can imagine this happening repetitively then you can see how the tendons would become irritated then inflamed.
This impingement can be due to several reasons one of which is inadequate strength of the rotator cuff. One of the primary roles of the rotator cuff is to stabilize the head of the humerus in the shoulder socket and thus prevent it from gliding upward into the acromion. Another common factor that predisposes one to shoulder impingement is the shape of the acromion. The shape of the acromion is classified as a type I, II and III. The shape of a person’s acromion is genetic. It is the type III or ‘hooked’ acromion that predisposes a person to impingement. The ‘hooked’ acromion decreases the subacromial space (space between the acromion and humerus). The type of acromion can be identified on an x-ray. Other factors that can contribute are poor upper body posture, and improper weight lifting techniques.
Some common signs that may indicate you have impingement are pain with raising your arm overhead, reaching behind your back, and inability to lie on the affected shoulder. If the condition is severe or has been ongoing for sometime then weakness in the affected extremity can develop secondary to the pain.
Shoulder impingement can typically be resolved with conservative treatment, which may include physical therapy, anti-inflammatory medication, and avoidance of aggravating activities. Physical therapy would involve strengthening the rotator cuff and scapular stabilizers, stretches, proper weight lifting instruction and soft tissue mobilization (to break up scar tissue). If conservative treatment isn’t undergone or if condition is allowed to persist for a prolonged duration then the condition could potentially progress to a rotator cuff tear.
If you are experiencing shoulder symptoms that are similar to what have been described above or are unsure of why your shoulder hurts then feel free to contact us at COAST Physical Therapy Services and we can determine the appropriate course of treatment for you.