By Justin Dudley, PT, DPT, EMT – Owner and Physical Therapist of Cascade Sports Injury Prevention & Physical Therapy – In-House Physical Therapist for Crossover Symmetry

High Intensity Interval Training (H.I.I.T) & Shoulder Imbalance

The demands of the muscles groups required to accomplish the High Intensity Interval Training (H.I.I.T) sport need to be complemented with shoulder rebalancing strengthening exercises. The typical H.I.I.T athlete has overdeveloped upper trapezius, levator scapulae, deltoid and rhomboid muscles as a result of our sport, and consequently relatively speaking underdeveloped lower trapezius, middle trapezius, serratus anterior and rotator cuff, frequently throwing our shoulders into imbalance.

High Intensity Interval Training incorporates functional movements while moving large loads over long distances in a short amount of time. In order to perform these high demand athletic movements, it is important to make sure that the prime movers in the body have a stable platform to operate on.

The Crossover Symmetry Shoulder System has been designed specifically to address and balance the stabilizers of the shoulder complex, including the scapular and rotator cuff muscles.

With the shoulder being the most commonly injured region in H.I.I.T athletes, it is imperative to supplement the mobility work performed regularly with a good stability program. The typical H.I.I.T athlete has developed upper trapezius, levator scapula, deltoid and rhomboid muscles primarily as a result of the shrugging motion. However, these are only a few of the 17 muscles that have attachments to the scapula and have a limited role in stability essential for shoulder health and performance. For healthy overhead shoulder mechanics, the upward rotators of the scapula and rotator cuff need to be proportionately strengthened to create balance in the shoulder. By improving the function of the scapular stabilizers and rotator cuff, the shoulder complex can operate at an optimal level, reducing excessive motion that leads to injury and impaired performance due to energy leaks.

The shoulder and the scapula are intricately linked: what affects the scapula will affect the shoulder and vice versa. The shoulder joint is often referred to as a ball and socket joint. However, it is important to realize that the shoulder is structured more like a golf ball on a tee, with the ball being much larger than the socket. This inherently allows for a great deal of mobility at the expense of stability, setting up the potential for injury and impaired balance and performance.

The scapula, or shoulder blade, is the triangular shaped bone in the upper back that is the critical link between the arms and trunk of the body. It is the foundation upon which all upper extremity strength and function is built. Unlike a house where the foundation is fixed in cement, the scapular foundation moves in three dimensions, like a gyroscope, changing the orientation of the socket to follow the movement of the arm. When raising your arm fully over your head, 2/3 of the motion occurs at the shoulder and 1/3 occurs at the scapula. As the scapula is moving in sync with the arm, it needs to remain a stable base of support to efficiently transfer energy from the body into the arms.

In the overhead athlete, the scapula is responsible for transferring the power produced from the legs, hips, core and torso. Ideally this is a stable, yet mobile, platform with minimal energy lost during athletic movement. However, with only one boney attachment between the arm and the trunk, the sternoclavicular joint, the efficiency of energy transfer through the scapula relies on the stabilizing muscles. If the scapula muscles are functioning at a sub-optimal level due to weakness, imbalance and poor neuromuscular control, the scapula will be pulled off the rib cage resulting in scapular winging and a large energy leak in the kinetic chain.

Shoulder impingement is a very broad term that refers to shoulder pain secondary to the pinching of structures within the shoulder complex and is unfortunately too common with high intensity interval training. The most common cause of shoulder impingement is poor shoulder mechanics during repetitive overhead activities. Poor shoulder mechanics often are the result of faulty posture, poor scapula positioning, muscular imbalance and poor rotator cuff control.

The Crossover Symmetry Shoulder System addresses rotator cuff control as well as scapular balance and function. The rotator cuff is comprised of four muscles that are responsible for keeping the ball, or humeral head, centered in the socket throughout shoulder range of motion. As the arm is elevated overhead, the ball has a tendency to want to migrate up in the socket based along the direction of pull of the big Deltoid muscle. This upward migration can cause pinching of structures within the shoulder joint causing pain and leading to what is known as sub- acromial impingement. It is the responsibility of the rotator cuff to minimize this upward migration.

Scapular dyskinesis is simply defined as altered position and motion of the scapula as a result of poor scapula positioning, movement, muscular imbalance and scapular strength. Unfortunately, even with the deltoid/rotator cuff functioning at an optimal level, the scapula position/movement/balance needs to be accurately controlled by the scapular stabilizing muscles to prevent shoulder impingement. Clinical research has documented the association between scapular dyskinesis and shoulder injuries.

H.I.I.T athletes are asked to move very heavy loads, quickly over large distances or large numbers of repetitions on a regular basis. Efficiency of movement is essential to being safe and effective in this sport. Any abnormal or excessive movement during these dynamic exercises is a waste of valuable energy, and often results in decreased total load movement tolerance. By enhancing the balance and function of the stabilizing structures in the shoulder, the prime movers are able to perform their duty without wasting energy attempting to perform a secondary task like stability.

Let’s take the example of a Thruster; much of the power for this lift comes from the legs, hip, core and trunk with the final “thrust” coming from the shoulders. If there is poor energy transfer from the body to the arm, the maximal effort load will be reduced. Similarly, if the prime movers of the shoulder complex for this task (Deltoid, Upper Trapezius and Levator) are required to move the load, as well as provide secondary stability to the shoulder, the total amount of work applied toward raising the weight is reduced due to a diversion of some of the workload to stabilization. Improve stability and you will improve efficiency and your max lifts.

H.I.I.T athletes need to further strengthen thus balance the shoulder complex via scapular upward rotation stabilizing muscles and the rotator cuff glenohumeral stabilizing musculature that don’t get as much work in the sport itself.

For example:

  • Upper Trap dominance requires additional Lower Trap strengthening to improve balance to the scapula upward rotation force couple.
  • Levator Scapulae dominance from shrugging which causes scapula downward rotation requires additional lower trap and serratus anterior strengthening to improve upward rotation of the scapula balance.
  • Rhomboid dominance a scapular stabilizing downward rotator requires additional supplemental strengthening to the middle trap a scapular upward rotator stabilizer.
  • Deltoid dominance requires specific supraspinatus and infraspinatus strengthening to counteract the upward humeral head migration to stabilize and center the humeral head in the joint.
  • Anterior deltoid dominance requires additional posterior deltoid strengthening to prevent shoulder imbalance.
  • Tight pectoralis minor needs to be stretched to prevent the shoulders from being pulled forward, allowing good posture. Stretching can be active vs passive if used on every rep.

The Crossover Symmetry Shoulder System incorporates all the above supplemental work in a very efficient manner. It addresses the specific needs, time constraints and demands of the H.I.I.T athlete, and combines the four phases of Crossover Symmetry (Activation, Activation+, Recovery, and Mobility) as well as the high intensity scapular strengthening program IRON SCAP (Strength) to promote a healthy, optimal functioning shoulder complex that has the ability to reach its true potential.