Physical therapy exercises for shoulder pain are specific to each individual person. This is typically determined by what is found in their initial evaluation. Each exercise performed targets something that might be missing or lacking, such as range of motion, muscle activation and coordination, or strength. While exercises will be different for each person, there are common muscles that are targeted by physical therapists. This could be due to poor muscle activation, muscle weakness, or both! Keep reading to learn about key muscles and muscle groups needed for shoulder pain and proper biomechanics.
Biomechanics of the Shoulder
The shoulder joint itself is complex due to it being a very mobile joint. But due to its greater mobility, it then loses stability. The shoulder is sometimes referred to as the shoulder complex because there are four different joints that all play a factor in the movement of the shoulder. Refer to this article to see an in depth look at the shoulder complex and its anatomy.
Commonly Targeted Muscles…
To Improve Extensibility (Let’s Stretch!)
The following is a list of muscles/muscle groups that are commonly found to be stiff. Because the shoulder complex has so much mobility, it is important that it moves as well as it should. Thus, physical therapists strive to target the areas around the shoulder that are stiff and preventing proper biomechanics of the shoulder complex. Check out this post to learn how to stretch a few of these areas listed below!
Pec Major/Minor
Pectoralis major is a large fan-shaped muscle in the front of the chest. When this muscle gets tight, it causes the shoulders to round and internally rotate. This can make it more challenging to lift your arm up, but it also feeds into this phenomenon called reciprocal inhibition. When an agonist muscle or muscle group contracts, the antagonist muscle or muscle group is inhibited.
When the pec major muscle is stiff, it pulls where it attaches on the humerus in the front of the shoulder. It rounds the shoulder giving you this forward slumped posture. Because the muscles in the chest and front of the shoulder are tight, it “shuts off” or inhibits the posterior shoulder musculature. Hence why the muscles in the back of the shoulder tend to be weak (continue reading to find out which muscles in the back of the shoulder are weak).
Reciprocal inhibition depicts the inhibition or relaxation of muscles on one side of a joint while the agonist muscles on the other side contract.
Pectoralis minor is a smaller muscle that connects onto the upper ribs and scapula (shoulder blade). Due to its attachment sites, the pec minor muscle can change the positioning of the shoulder blade when the muscle is too stiff. A tight pec minor tips the shoulder blade forward making it more difficult to lift your arm up overhead.
Lats/Teres Major
Latissimus dorsi and teres major (also known as “baby lats”) can limit arm movements overhead if the muscles are stiff. Latissimus dorsi is a very large muscle that has a lot of attachment points. It originates on a portion of the thoracic spine, the thoracolumbar fascia, iliac crest, the lower ribs, and the inferior angle of the scapula. It inserts onto the front of the shoulder near the bicipital groove area. This muscle adducts, internally rotates, and extends the shoulder as well as helping the trunk move when the upper extremities are fixed. Teres major performs the same actions of adduction, internal rotation, and extension of the shoulder.
Due to their actions of internally rotating the glenohumeral joint, stiff lats or teres major can cause some pinching in the shoulder joint. This can alter the normal biomechanics when reaching overhead. A stiff latisimmus can also limit the arm when reaching upwards and overhead.
Upper Trap/Levator scapulae
While both the upper trap and levator scapulae have attachments onto the cervical spine, they also have attachment points onto the scapula. This plays a role in how the shoulder moves as good mobility of the shoulder blade is essential for optimal shoulder mechanics.
The trapezius is a very large muscle. Due to its large size and many attachments, it is further broken down into different sections: upper, mid, and lower trap. The actions of this muscle is diverse because to its many attachment points. While the upper trap tends to be overly tight in many people, the mid and low trap tend to be especially weak. Getting all three areas of the muscle to work synergistically is important. When the upper trap is tight or overactive, it can cause the shoulder blade to elevate too much. This can alter the biomechanics of shoulder movement.
The levator scapulae originates on the transverse processes of C1-4. It inserts onto the upper region of the medial border of the scapula. This muscle can elevate and downwardly rotate the scapula when it is tight. The scapula should upwardly rotate 60 degrees to help flex the shoulder to full range. If the levator muscle is tight, it would be doing the opposite effect.
To Improve Strength or Activation (Let’s Turn It On!)
Along with commonly stiff muscle groups, there are also weak muscles commonly found that are important for the shoulder complex. Physical therapy exercises for shoulder pain work to strengthen the areas that are weak to help improve the way the shoulder moves.
Mid/Low Trap
The mid trap fibers retract or adduct the scapula. The low trap fibers depress the scapula. Together, the upper and lower fibers help upwardly rotate the scapula. Imagine if the upper trap fibers were excessively tight and the lower trap fiber were weak. The direction of pull on the shoulder blade would be off making it much more difficult to lift your arm without pain.
The mid and low trap fibers are big targets for physical therapists because these are often forgetting about that are crucial for shoulder mechanics. Something as simple as reaching into a cabinet to grab your favorite coffee mug for that liquid gold in the morning can become an exhausting task. Especially when dealing with increased pain levels. You don’t realize how much you use your arm until you realize how much is affected by the sudden pain that you feel.
But it doesn’t always have to be this way! Training the shoulder complex by strengthening is a great way to restore proper biomechanics.
Infraspinatus
The infraspinatus is the main external rotator of the shoulder joint. The muscles of the shoulder complex that tend to get stiff are internal rotators. As stated earlier regarding reciprocal inhibition, the external rotators then become inhibited and weak. While it is important to stretch out the internal rotators, it is equally important to strengthen the external rotators. You must address all pieces of the puzzle to help prevent the faulty mechanics (and pain) from coming back.
TL;DR
This post is all about education on physical therapy exercises for shoulder pain, but around why these exercises are important. They target which areas are stiff and need to move better. They also target weak muscles and help strengthen them. Both are important for the biomechanics of the shoulder complex. Head to this post to actually perform commonly prescribed exercises!
Tera Sandona is a licensed Doctor of Physical Therapy (DPT) and the founder of PT Complete. She helps high-achieving women break out of cycles of chronic pain, stress, and burnout through her Regulate and Rebuild Method, a sequenced approach that addresses the nervous system first and builds strength second. Her work focuses on helping women finally understand their bodies, rebuild strength, and create lasting resilience that fits real life.
