This article is based on the recent systematic review article which analysed shoulder impingement across a variety of studies
WHAT IS SHOULDER IMPINGEMENT?
“Shoulder impingement” is something you may hear thrown around at your gym or work, but what does it actually mean?
Shoulder impingement, or subacromial impingement describes pain or discomfort associated with the subacromial space. The subacromial space is a small space in the front/top of the shoulder between the acromion (top of the shoulder blade) and the head of humerus (top of the arm bone) as in the picture below. Within this space several structures are prsent including; the rotator cuff tendon, subacromial bursae (fluid-filled sac), and for this reason irritation/inflammation of these structures in the forms of bursitis and tendinosis/tendon tears are generally implicated.
There is some confusion regarding the term shoulder impingement, and although it is less of a diagnosis and more of a description of symptoms, the term “Subacromial Impingement Syndrome” (SAIS) or “Subacromial Pain Syndrome” (SAPS) has been used as a general diagnostic term, the latter of which introduced due to the inconclusiveness of an “impingement” process technically occurring.
HOW DOES IT HAPPEN?
During shoulder movement, the muscles in the shoulder region must be recruited in correct timing and activation in order to maintain the head of the humerus in the socket of the shoulder joint. If the muscles fail to maintain this, the humeral head may ride up and cause narrowing of the previously defined subacromial space.
Structural Patterns and Other Contributors
Impingement can also occur from a congenital altered shape of the acromion causing narrowing of the subacromial space (as in the image below). Other potential contributors to abnormal orientation and rhythm of the joint include posterior capsule tightness, rotator cuff weakness or posture-related contributors such as the orientation of the thoracic spine, all of which are generally addressed during the rehabilitation process.
What starts the process may be a specific incident causing a tear or irritation of a structure in the joint, although it is more commonly a gradual process noticed over time whereby pain in the front of the shoulder, and at times referring into the upper arm, is noticed, commonly with overhead activities. This can include overhead lifting in the context of resistance training, such as shoulder-press exercises, or even during daily tasks such as washing hair, brushing your teeth or dressing.
HOW IS IT TREATED?
1. PAIN-RELIEF TECHNIQUES
Pain relief techniques include the use of anti-inflammatory medication (as guided by your doctor) in order to decrease pain levels, these are likely to be used as an adjunct to physiotherapy/exercise due to their generally short-term effect.
B) Corticosteroid Injection
Shoulder impingement, particularly when associated with subacromial bursitis is commonly managed with corticosteroid injection, although these may have value in reducing pain levels, they are generally advised only as an alternative if exercise or other treatment strategies are not possible, particularly due to potential side effects and generally inconclusive long-term benefits
The education process with a physiotherapist involves analysing current exercise routines, physical demands and aggravators, and managing/modifying these in order to prevent exacerbation of the pain and maintain safe levels of activity. A common strategy, for example, is to avoid overhead movement at work. Education also involves explanation of the condition, pain-relief strategies (as discussed above), expected time-frames and the potential for further investigations or imaging. This process is highly individualised is likely to be different person to person.
B) Exercise - Strengthening and muscle activation
Exercises for shoulder impingement symptoms tend to focus on rotator cuff and scapula strengthening. The rotator cuff are a group of muscles located at the back of the shoulder which are responsible for rotation of the shoulder as well as maintenance of the ‘ball’ in the ‘socket’ in our shoulder. Strengthening of the surrounding scapular muscles can also be often prescribed in order to ensure the effective position of the shoulder blade and rhythm of the shoulder through overhead movement.Some examples of exercises you may be prescribed are shown below. These aim to work on the muscles responsible for posture and shoulder rhythm including the rhomboids and rotator cuff muscles.
Horizontal Row Exercise
Resisted External Rotation Exercise
C) Exercise - Stretching
Stretching of muscles assessed to be tight can assist in re-orientation of the shoulder blade, restore upright posture and symptom relief, commonly focusing on the pectoral muscles due to their relation to rounded shoulders (as seen in the image below). These exercises are typically tailored to each individual from their physiotherapist based on a series of assessments to examine the presence of weakness, inactivity, tightness or instability.
Pectoralis Stretch Exercise
D) Manual Therapy
Manual therapy in the form of massage and joint mobilisation to structures in the shoulder, neck and upper back as an adjunct to exercises can also serve to promote further improvements in pain and function
3. OTHER STRATEGIES
Other strategies which can be employed in management of subacromial pain include;
Passive Techniques; taping in order to improve postural function and assist in pain-relief may also provide additional benefits, when used as a supplement to a core exercise program. Other passive techniques such as shockwave therapy and ultrasound, similarly to tape, have been found to have a potentially small benefit, when combined with tailored exercises.
Surgery: Surgery to manage subacromial pain is not common and its effectiveness over physiotherapy is not particularly conclusive, although it may be indicated for a small group of patients in very specific circumstances, based on each individual’s case considering factors of; age, response to treatment and presence of structural tears, amongst others.
Overall, although more research needs to be done, the available research generally indicates for the prescription of a tailored exercise program to manage subacromial pain, with the supplementation of manual therapy and pain-relief techniques as adjuncts.
For further advice or if you're getting shoulder pain, for a full assessment and a tailored exercise program, feel free to get in touch with us on 47354214 or