Of all the joints in the body, the shoulder is one of the most complex. The dilemma with the shoulder is the relationship between mobility and stability. This is due to the bony congruency of the joint. The shoulder joint consists of the head of the humerus (top of the arm) and the glenoid fossa of the scapula, (the edge of the shoulder blade).
A common analogy used to gain insight into this anatomical structure is a golf ball on tee; a relatively large humeral head rests on the shallow and relatively flat surface of the glenoid of the scapula. Due to this lack of bony support, stability is improved by various passive and active structures. One of these passive structures is the labrum, a fibrocartilage ring around the periphery of the glenoid that deepens the joint and provides a barrier for the humeral head. These passive structures only provide minimal support to maintain the humeral head within the joint. Active structures (muscles) work synergistically to centralize the humeral head in the glenoid with movement to provide stability. In total, 17 muscles attach to the scapula and work as a team to bring both stability and mobility to the joint.
Due to the lack of static stability, the shoulder is often a point of dysfunction and pain for people. In order to optimize function and avoid painful injuries, it is important to ensure that the shoulder is in the optimal position to move with the proper mechanics prior to participating in exercises under heavier loads. In general, the presence of pain and dysfunction around a joint can be due to the over activity of the power producing muscles and the inhibition of deeper, stabilizing muscles. Therefore, ensuring proper shoulder function includes lengthening the tight, overactive muscles, and activating, or shortening, the inhibited stabilizing muscles.
Here a few exercises that can help create this balance between stability and mobility in order to prime the shoulder for movement:
Mobility
Perform each stretch 3 times for 20-30 second holds:
- Pectoralis Minor Door Stretch: The pectoralis minor muscle originates on the ribs and attaches to the front of the shoulder blade pulling the scapula into a forward tilt. This forward tilt puts the shoulder at a mechanical disadvantage for movement. In order to stretch this muscle, face the door frame with the arms in a “field-goal” position resting on the door frame. Gently lunge forward until you feel a stretch in the front of the shoulder.
- Latissimus Dorsi Stretch with Stick: When the “lats” are tight and gripping on the shoulder blade, they can cause a downward rotation of the scapula. To stretch the lats, kneel on the floor and sit on your heels while facing a chair, bed, or bench. Place the elbows shoulder width apart on the chair/bed/bench with the palms facing upwards and the wrists held slightly wider than the elbows. Drop your chest towards the floor while keeping the abdominal muscles tight (keep the ribs dropped down towards the pelvis).
Activation
Perform 3 sets of 10 of each exercise prior to engaging in futher movements or exercises:
- Serratus Anterior Wall Slides: The serratus anterior wraps underneath the scapula and creates an upward rotation movement that is optimal for proper shoulder movement. To engage the serratus anterior, stand facing a wall with the back of the hands and forearms on the wall directly in front of you. Press through the elbows into the wall and slowly slide the forearms up and down. You should feel a contraction of a muscle underneath the shoulder blade.
- Lower Trapezius Reach: The lower trapezius originates on the lower thoracic vertebrae and attaches to the lower inferior border of the scapular spine. In order to activate the lower trapezius, get into a quadruped position on the elbows and knees on the floor (child’s pose) or a bed. With your hips back on your heels, reach away from yourself overhead with one arm, sliding your hand on the bed or floor to elevate your scapula. Once you have reached as far as you can, lift the arm upwards towards the ceiling and hold for two seconds. Repeat on both sides.
- Shoulder Retractions “No Moneys”: In order to engage the middle and lower trapezius to “stack” the shoulder in a retracted position, sit upright with upper arms and elbows against the body and the elbows bent to 90 degrees. With the palms up, bring the elbows backwards and squeeze the shoulder blades together as if trying to say “I have no money”. Hold for 5 seconds each repetition.