Shoulder Impingement & Pain with Overhead Movements
Impingement is a condition we commonly see in the PT world. This is largely due to the fact that the shoulder is extremely mobile. With its ability to move in multiple directions comes an increased likelihood that one of those motions could become restricted due to injury or due to chronic conditions like overuse. Similar to the hip, which is also extremely mobile and prone to impingement, shoulder impingement is very treatable!
So what even is impingement? Shoulder impingement syndrome is a collection of symptoms a person experiences due to the outer edge of their shoulder blade (the acromion) rubbing on or pinching the tendon or muscles of the rotator cuff beneath it. Symptoms can include pain with certain movements, tenderness to the touch, irritation, limited range of motion, difficulty with overhead movements, feeling “stuck,” and discomfort laying on your affected shoulder at night. So what causes impingement to occur in the first place?
Rotator cuff tendon irritation, swelling or damage due to injury, repetitive activity or overuse, or age-related changes.
Bursa irritation or inflammation between the tendon and the acromion. Bursae are fluid-filled sacs that ease the slide and glide of muscles and tendons over bones. Bursa can become inflamed with overuse.
Acromion shape, discussed more in next section.
Certain people will be more likely to experience shoulder impingement simply due to their boney anatomy. There is a portion of bone on the scapula (AKA shoulder blade) called the acromion. If you feel your collar bone and continue tracing it with your fingers out to the side, the acromion meets the end of your collarbone. There are three common shapes to the acromion: flat, curved, and hooked. A fourth type is the convex or upturned acromion, but this is much less common. People with a hooked acromion are more likely to experience impingement simply because there is slightly less space in that area (see photo attached). This is what we typically know as primary impingement.
Secondary shoulder impingement is often due to chronic overuse and loading intolerance to the shoulder muscles; this can happen to anyone, regardless of acromion type. Forward shoulder or more of a rounded posture has also been reported to be associated with secondary shoulder impingement; over time the head of your arm bone may become situated further forward than it ideally should be within the shoulder joint, thus limiting the space for it to move efficiently. Oftentimes poor posture is secondary to muscle imbalances between the backs of the shoulder blades, where these muscles that keep your shoulder blades retracted and stabilized are weak and the muscles at the front of the shoulder are tight or overused.
There is a premise called scapulohumeral rhythm that describes how the shoulder blade and arm bone must work together to achieve full range of motion at the shoulder. For every 2 degrees of motion of the arm within the shoulder joint, 1 degree of motion is required from the shoulder blade for optional movement. Typically we find that the smaller muscles around the shoulder blade are weaker or imbalanced, thus impacting our ability to effectively and efficiently move our shoulder blade. This forces other muscles around the shoulder and arm to compensate and attempt to achieve additional motion.
Luckily for those experiencing signs and symptoms of shoulder impingement, physical therapy is an incredible tool to get you feeling and moving better! Physical therapists are trained in the assessment and intervention of impingement. We do specific range of motion tests, muscle tests, and special tests to rule in or out whether you have impingement, as well as the major deficits contributing to its presentation within your body. These are the key things we will target with exercises for mobility, strength, pain management and hands on treatment as appropriate.
Have more questions about your shoulder pain or limitations? Think you might have something different than shoulder impingement going on? We would still love to see you in the clinic for a thorough evaluation! We would be happy to chat further about how Loon State Physical Therapy can be your teammate in getting you back to moving and feeling your best! Call us at (612) 405-8503 or book with us online at www.loonstatephysicaltherapy.com for an in-person or virtual appointment.
Bailey Van Oosbree, Doctor of Physical Therapy
Loon State Physical Therapy