Shoulder Impingement
One of the most common shoulder diagnoses I see is shoulder impingement. This is the painful “pinching” of a tendon, most commonly the Supraspinatus tendon and occasionally the Infraspinatus tendon, against surrounding bone. Shoulder impingement can occur due to faulty shoulder mechanics, repetitive motions, muscular imbalances, prolonged poor posture, and/or injury to the shoulder joint that creates inflammation. Examples of repetitive overhead activities that are risk factors for impingement include: painting, lifting, swimming, tennis, baseball etc.
What do I mean by faulty mechanics?:
During elevation of the arm (reaching overhead), muscles that attach to the scapula must be strong enough to upwardly rotate the scapula in rhythm with the muscles that are elevating the arm (humerus bone). If this movement is not smooth and properly executed by all muscles involved, impingement can occur. Impingement can also occur if the glenohumeral joint and scapulothoracic joint lack proper mobility and are unable to glide correctly.
In order to best understand shoulder impingement, a review of the shoulder girdle anatomy is helpful.
The shoulder girdle is one of the most complex joints in the body; it is made up of 3 different bones — the humerus (upper arm bone), the clavicle (collarbone), and the scapula (shoulder blade). There are 3 joints that must be functioning properly to ensure pain-free and optimal shoulder motion: the acromioclavicular joint where the shoulder blade and collarbone meet, the glenohumeral joint where the ball of your upper arm and the socket meet, and the scapulothoracic joint which is not a true anatomical joint but is the junction of the front surface of the shoulder blade and the thoracic cage. The rotator cuff muscles (supraspinatus, infraspinatus, teres minor, and subscapularis), along with many other important muscles, help to maintain proper alignment of these bones and ensure smooth joint movement. Due to minor discrepancies in anatomy, some people are more likely to develop shoulder impingement syndrome than others.
Can poor posture lead to shoulder impingement?
The supraspinatus tendon runs through a space at the top of the shoulder bone called the subacromial space. This space narrows when you hunch or round your shoulders which leaves less room for the supraspinatus tendon to easily move causing this tendon to become pinched and rub against the natural padding in the shoulder (subacromial bursa). This irritation and improper mechanics can result in inflammation of the tendon and/or bursa, causing pain. You may not have realized how your posture while sitting in the car driving, working on your computer at your desk, texting etc. could be contributing to the development of shoulder pain.
What are some easy ways to improve your posture?
When seated:
Keep your feet planted on the floor or on a footrest (crossing your legs can put your body in a hunched position)
Try not to sit too far back in your seat (leave a small space between the front of your seat and the back of your knees to encourage proper muscle activation and limit chances for rounding your back)
Adjust your chair accordingly to support your lower and middle back and prevent rounding
Relax your neck and shoulders (your forearms should be parallel to the ground)
When standing:
Be cognizant of neck positioning- is your head too far forward? If yes, try a chin tuck exercise
Stand up tall with your shoulders pulled down and back
How close are your feet to one another? Shoot for shoulder-width apart
Let your arms hang naturally down by your side, not crossed etc.
Refrain from locking out your knees in standing, try to keep a slight bend
Is your butt sticking out behind you and is your low back very curved? Engage your abdominals and slightly tuck your pelvis to reduce the stress on your low back
How do you know if you have shoulder impingement?
Impingement symptoms commonly occur when reaching overhead and reaching behind your back. Pain can be felt in the top (superior) or back (posterior) of the shoulder. For example, if any of these activities are uncomfortable you may have impingement syndrome: reaching behind your back to clip your bra, reaching overhead to put on your coat or blouse, or reaching overhead to put clean glassware away from the dishwasher.
So, you did the movements noted above and they were painful…now what?
It would be in your best interest to temporarily avoid movements that increase your symptoms. An assessment by a Physical Therapist can determine what is contributing to your shoulder symptoms and how to best address it. A Physical Therapist will assess the mechanics of the shoulder joint, the strength of the shoulder and scapular muscles, mobility of the cervical and thoracic spine, and overall posture. Addressing these imbalances and faulty mechanics will help the shoulder to move correctly, decrease pinching of the rotator cuff tendons, and help you get back to the activities and hobbies that you love. If not properly treated, tendons involved in shoulder impingement can start to thin and even tear.
