The shoulder complex is one of the more unstable joint structures in the entire body. Some people colorfully describe the shoulder structure being like a golf ball sitting on a golf tee or a basketball on a tea saucer. There are very few bones associated with the shoulder, in fact only 4.
The shoulder is known as a hang down joint. The arm hangs off the top of the shoulder girdle like the struts off a yoke. The collarbone above the ribs in the front is like a girder giving the shoulder complex width and reinforcement allowing a broad wrap around for the upper chest offering shape and form to the upper body. The shoulder girdle is designed to be wide, open, and strong with the pectoral muscles and deltoids wrapping around the shoulder to provide strength and stability right into the upper back and neck. There are 30 muscles, 6 ligaments and 4 bones that make up the shoulder complex.
The shoulder joint is unique in the musculoskeletal system as it is the only joint that is fixed and stabilized mostly by muscles and by very few ligaments. So getting the correct balance between the postural and phasic muscles in the shoulder girdle are paramount for increasing performance whether it is for reps or strength or ideally power. Active and static shoulder stabilizers maintain balance and control. The static stabilizers are the shoulder capsule, the labrum (soft tissue) the bones and the so-called vacuum effect of the humerus and the glenoid bone being held together by “adhesion and cohesion” of fluids and vacuum forces. The functional muscle control is the most important factor in the stabilization of the shoulder girdle. The smallest of muscular and mechanical imbalances can lead to weakness, instability, and pain!! Mechanical alignment is key to its optimal stability with muscle strength and control balancing these opposite and opposing forces; herein lies the key to power and ease of movement.
The 2 most important muscles in scapular stabilization are the lower trapezius and the serratus anterior which hold the scapular (wing) in place. The subscapularis muscle under the scapular is key to holding the shoulder in the correct position when the arm is by the side and also preventing posterior subluxation or instability when the shoulder is in full external rotation. Then there are the 2 posterior shoulder rotators; the infraspinatus and teres minor that are involved with holding the humeral head against the glenoid preventing an anterior sheering force in the shoulder. These two muscles are sometimes referred to as the hamstrings of the shoulder as they act like a break or decelerator for the arm when we are throwing a ball. For most people these 2 muscles are restricted and tight. They will need lengthening before they need stability and strength.
The shoulder is connected to the neck via the upper trapezius muscle that inserts along the upper spine of the shoulder blade and anchors itself onto the nuchal ligament on the ridge of the occiput. In effect, the upper trapezius holds up and extends the head and neck giving the support and strength needed to hold your head up high. The deeper levator scapular muscle is also there to connect with the head and neck. When in alignment and balance this will create upright support for the upper back and neck working in sync with the upper trapezius. When out of balance it will pull the head, neck and shoulders right out of the line of gravity causing untold chain reactions of stresses and strains throughout the musculo skeletal system right down to the foot where we connect with the ground and dispel forces from propulsion and locomotion. The levator scapular when over-loaded, is associated with all kinds of referred head pains. This is a key area for manual therapists to release and lengthen and regain head alignment and balance.
The shoulder also has direct connections to the lumbar spine via the lower trapezius, which anchors itself onto the inferior angle of the lower scapula and to the latissimus dorsi that ties right into the coccyx in the base of the spine. The scapular is the key link in the transfer of energy from the trunk and lower limbs to the shoulder and up through the neck. Think of the movements involved in throwing a ball. It requires a total connection from the foot to the fingertips and full co-operation from the shoulder accelerators in the front and decelerators in the back of the shoulder to propel the ball or the club head for maximum speed and efficiency.
Scapular mobility and stability always start with optimal mechanical and muscular balance. Any deviation from the correct symmetry and you begin to notice irritating overuse injuries with sprains and strains that manifest in weakness and deficiency. It is said that a 50% decrease in rotator cuff forces result in a 50% increase in the anterior displacement of the humeral head in response to any load on the shoulder joint. In short, stretch the front of the shoulder and strengthen the back of the shoulder complex to increase power and decrease the likelihood of injury!! We use a 3 to 1 formula of strength to length.
Have your shoulders thoroughly scanned for misalignments and weaknesses. Lengthen the short restricted tissues, stabilize, and strengthen the weaker structures to look good and to perform at your level best.