By: Dr. Rachel Tavel, DPT.
When people hear the word “core” they usually think about their abdominal muscles. We all know that we have to have a strong core for improved posture, balance, and overall strength. But what if we told you your shoulders have their own core?
The scapula, commonly referred to as the “shoulder blade,” is a large, flat bone that sits on top of the rib cage and is held in place by the many muscles of the shoulder girdle. Unlike most other joints in the body, the scapulothoracic joint does not connect to the body by fibrous (eg: the skull), cartilaginous (eg: intervertebral discs), or synovial (eg: the hip) tissues. The scapulothoracic joint relies on the coordinated dance of 17 muscles (*see bottom of post for the complete list of muscles that attach to the scapula), as well as its mobility at three other joints — the acromioclavicular, sternoclavicular, and glenohumeral joints — to provide stability for the rest of the arm and shoulder.
Weakness in any one of the muscles attaching to the shoulder blade, particularly in the larger scapular muscles such as the serratus anterior, latissimus dorsi, rhomboids, and trapezius muscles, can affect the way the scapula moves and how the shoulder joint functions.
The shoulder requires both mobility and stability in order to support and stabilize the rest of the upper extremity. Poor movement patterns and/or deficits in muscle strength at the scapula can lead to uncoordinated movement, instability and pain/injury in the elbow, wrist, and hand.
Think of the scapulae as the foundation of your house. Your house is only as sturdy as its foundation, just as a tree is only as sturdy as its roots. Similar to a tree or a house, upper body strength relies heavily on the stability provided by the scapular muscles, which ground the upper extremities and allow for greater distal strength.
Whether you play a racquet sport or you are just trying to put your suitcase in an overhead compartment on an airplane, scapular muscle strength and mobility are key to preventing injury. Weakness in the shoulder “core” and not using the larger, stronger muscles closer to the body can lead to overuse of the smaller muscles in our extremities. Common overuse injuries include tennis elbow (lateral epicondylitis), golfer’s elbow (medial epicondylitis), tendinitis, DeQuervain’s tenosynovitis, and skier’s thumb.
So how do we make this “shoulder core” stronger and protect our elbows, wrists, and hands from injury? Here are 5 exercises to improve scapular stabilization:
- Standing Rows: Stand facing the anchor with resistance band at elbow height. Step back until your arms are straight and the band has mild tension. Stand tall, bringing shoulders down and back and engage abdominal muscles (do not hunch shoulders or push out ribs). Draw elbows back while squeezing shoulder blades together behind you. You should feel the muscles between your shoulder blades activate and your chest opens up. This strengthens the scapular muscles for improved posture and scapular positioning. (Perform 2 sets of 10.)
- Dynamic T and I: Lay face down with arms out to sides like the letter “T.” While drawing the belly in and maintaining a neutral spine, lift arms up to sides while maintaining a “T” position by engaging muscles between shoulder blades. Gently lower arms until they are down by your side, creating the letter “I.” Return to “T” and repeat this movement. Do not arch lower back or lift head up. (Perform 2 sets of 10.)
- Bilateral External Rotation: Stand tall with shoulders down and back drawing the belly in towards the spine. With elbows at 90-degrees and resistance band in hands, gently open arms out to sides against resistance. Don’t let shoulders tilt forward — keep them down and back. This strengthens the rotator cuff muscles. (Repeat 2 sets of 10 repetitions.)
- Modified Plank With Protraction: Begin in a modified plank position resting on forearms. While maintaining a neutral spine (draw the belly up towards spine for transverse abdominus muscle engagement), activate serratus anterior by pushing through forearms, allowing shoulder blades to separate farther apart. Return to starting position. (Perform 10 reps holding 3 seconds each time you push arms away.)
- Pec Stretch, W, and Snow Angel on Foam Roller: Position yourself on a foam roller with both head and tailbone supported. For T: open arms out to sides and allow gravity to create the stretch. Do not force arms down to the ground if they do not touch. For W: bend both elbows and lower arms until arms hang at side. For Snow Angel: Begin with arms down by your side. Gently move arms out side to side and overhead like you are creating a snow angel, and return to start. Hold T/W for about 20 seconds. (Do not perform Snow Angel if you have shoulder pain with this movement.)
*The 17 muscles that attach to your shoulder blades:
- Serratus Anterior
- Teres Major
- Teres Minor
- Triceps Brachii long head
- Biceps Brachii
- Rhomboid Major
- Rhomboid Minor
- Omohyoid inferior belly
- Lattisimus Dorsi
- Levator Scapula
- Pectoralis Minor