Dryland Tip by Swimming World correspondent G. John Mullen of SwimmingScience.net and CenterofOptimalRestoration.com, Creator of Swimmer's Shoulder System
SANTA CLARA, California, September 25. THE rotator cuff muscles are the most discussed shoulder muscles in swimming, despite their minimal contribution for propulsion. However, anyone involved in swimming, or playing fantasy sports, has become an expert in the field of rehabilitation terminology. This basic understanding has expanded the field, allowing many to profess themselves as “experts” and many coaches to feel they have an adequate grasp on the subject.
Unfortunately, this surface knowledge and armchair theorizing causes myopia on a subject far more complex than band internal and external rotations.
Just because the rotator cuff muscles are the injured area, doesn't mean that they are the area of concern!
This cause and effect relationship has persisted too long in the sport, but simple associations get us into trouble. Just like in swimming, if a swimmer has hula-hoop hips and shimmies down the pool, it is possible they have a weak core, but it is more likely their body is out of streamline at another body part.
DON'T BE MYOPIC!!!! DON'T ASSUME, CHECK AND ASSESS! Look past the area of concern!
I've discussed the shoulder in great detail for Swimming World, but the rotator cuff muscle deserves its own story. This emphasis is not necessarily due to its importance, but due to its claim of importance. Before we continue, I'm going to make a few large claims:
1. The rotator cuff muscles are not the most important muscles for shoulder injury prevention.
2. The rotator cuff muscles' role is different from how most of the coaches (don't worry not just swim coaches) train them.
3. Performing excess band internal and external rotation increases the risk of shoulder injury for many swimmers.
I know what you're thinking, how can this be true? I've read popular fitness websites and attended ASCA meetings on shoulder injury prevention and the main emphasis was the rotator cuff muscles! I know, this is a tough pill to swallow, but certain dogma and misplaced precision have put these muscles on a pedestal. This is partly from old, outdated research being passed as new findings and/or undereducated experts making unjustified absolute claims. Another issue is surface knowledge experts proclaiming expertise. These problems have perpetuated the high incidence of shoulder injuries in our beloved sport!
The rotator cuff muscles consist of four muscles which surround the head of the humerus or upper arm. Use the below anatomy and action as a reference, for more detail purchase the COR Swimmer's Shoulder System.
ROTATOR CUFF MUSCLES
MUSCLE ORIGIN INSERTION ACTION
Supraspinatus Supraspinous fossa Greater tuberosity humerus Abduct glenohumeral joint
Externally rotate glenohumeral joint
Infraspinatus Infraspinous fossa Greater tuberosity humerus Externally Rotate glenohumeral joint
Horizontal Abduct glenohumeral joint
Teres minor Lateral border scapula Greater tuberosity humerus Externally Rotate glenohumeral joint
Horizontal Abduct glenohumeral joint
Adduction glenohumeral joint
Subscapularis Subscapular fossa scapula Lesser tuberosity humerus Internally Rotate glenohumeral joint
Horizontal Adduct glenohumeral joint
With the basics covered, let's talk about 5 considerations about the Rotator Cuff Muscles:
1. Stabilize … don't band: Many coaches perform shoulder injury prevention programs focused around one of the functions commonly depicted in anatomy books, internal and external rotation. Unfortunately, these muscles perform this function over and over in the water and have other main functions typically not considered an action. Specifically, stabilization is a theoretical stationary movement, yet essential for injury prevention, as instability likely irritates the rotator cuff muscles during fatigue.
One study analyzed the role of the rotator cuff stated:
“The rotator cuff architecture suggests these muscles are designed primarily for force production, congruent with their role as shoulder stabilizers (Ward 2006)”.
Their anatomical position helps perform internal and external rotation, likely assisting or contributing to stabilization as the larger internal and external rotator muscles (pectoralis and latissimus dorsi) dominant the main movement. Therefore, combining stabilization and internal/external rotation is mandatory, as muscles rarely have one function in dynamic movements like sports. Try the gangsta driver exercise.
2. Don't Overuse: While we are discussing band internal and external rotations, let's discuss volume. It is well established overuse and improper biomechanics are the main causes of shoulder injuries in overhead swimming (Macfarland 1996). In swimming, volume is necessary for development of ideal motor programs. However, assisting transverse plane (internal and external rotation) overuse likely contributes to shoulder injuries. Moreover, performing these exercises before to swimming likely fatigues the stabilizing muscles and increases their risk of injury during a 12,000 stroke workout.
Swim practice, like all exercise, causes microdamage to the soft tissues. In the shoulder, microdamage causes excesses movement and instability. Instability is caused by improper functions of the passive (ligaments, joint capsule) and active (rotator cuff muscles) structures, likely from fatigue during practice. If we fatigue the active stabilizers before a workout, the role of the active stabilizers is even more impaired. Serious reconsiderations on rotator cuff exercise placement and volume are necessary.
3. Don't Stretch: Once again, there are passive and active stabilizers of the rotator cuff muscles. It is likely, alterations in these structures allow large shoulder range of motions required for the early vertical forearm. However, it is impossible to speculate if swimming increases shoulder laxity or those with shoulder laxity are better at swimming, nonetheless swimmers are predisposed to develop shoulder instability. More importantly, if one started swimming in youth, they likely have the required shoulder range of motion for swimming success.
Therefore, stretching the shoulder for further range of motion seems unnecessary and dangerous, as this further stretches the stabilizers, impairing their ability to sense their joint position (joint proprioception), a potential cause for further tissue breakdown and injury (Herrington 2010).
4. Proper Length: Swimmers perform excess overhead motions. This results in dominant internal rotation musculature and an imbalance between internal and external rotator muscles. Many feel it is necessary to restore this disequilibrium through static stretching, as it results in immediately improves range of motion. However, the previous point argued against stretching and just because stretching “feels good”, doesn't mean it is appropriate, as stretching likely alters neural signaling (Blazevich 2012).
Instead, improving muscle length through passive soft tissue mechanisms, where the joint isn't stressed, is the key for much improvement. This method relaxes the muscle by providing a counter-irritant, allowing the muscle to retain to a more appropriate muscle length and react properly. Remember, the every muscle has an ideal muscle length and deviations increase the risk of compensations and injury.
5. Perturbations: Recent literature suggests the further an arm performs shoulder external rotation, the less joint awareness or proprioception exist. In swimming, unlike other overhead sports, high amounts of external rotation are not the key for success. Instead, internal rotation is the key, but I would argue this lack of joint awareness exists at all joint end-ranges-of motion. Therefore, teaching swimmers how to sense their shoulder position at different amounts of range of motion is mandatory for shoulder injury prevention and rehabilitation.
Last week, I discussed perturbations in the dryland tip: kneeling internal and external rotation with perturbation. This is only one exercise forcing athletes to stabilize their shoulder at various ranges of motion, no matter the mode of exercise, make sure you're teaching your swimmers joint awareness at a young age, not only for injury prevention, but for improvement in swimming motor control. Once again, this is a theoretical thought, but it is unlikely someone can in the water, which they can not do on land. Therefore, teach them the different positions outside of the water (don't overdo it) and see the translation into the pool.
The amount of shoulder injuries in the sport is unfortunate, but the fact some clubs are directly contributing to the high injury rate is a tragedy. Make sure you are implementing smart, realistic injury prevention programs on your pool deck, not isolated to the rotator cuff muscles. Moreover, injury prevention must compliment swimming training, making excess programs unrealistic and dangerous. Find the minimal effective dose for injury prevention and start helping prevent shoulder injuries!
References:
1. Blazevich AJ, Cannavan D, Waugh CM, Fath F, Miller SC, Kay AD. Neuromuscular factors influencing the maximum stretch limit of the human plantar flexors. J Appl Physiol. 2012 Aug 23.
2. Herrington L, Horsley I, Rolf C. Evaluation of shoulder joint position sense in both asymptomatic and rehabilitated professional rugby players and matched controls. Phys Ther Sport. 2010 Feb;11(1):18-22. Epub 2009 Nov 20.Macdonald G, Penney M,
3. Mullaley M, Cuconato A, Drake C, Behm DG, Button DC. An Acute Bout of Self Myofascial Release Increases Range of Motion Without a Subsequent Decrease in Muscle Activation or Force. J Strength Cond Res. 2012 May 10.
4. McFarland EG, Wasik M. Injuries in female collegiate swimmers due to swimming and cross trainingClin J Sport Med. 1996 Jul;6(3):178-82.
5. Ward SR, Hentzen ER, Smallwood LH, Eastlack RK, Burns KA, Fithian DC, Friden J, Lieber RL. Rotator cuff muscle architecture: implications for glenohumeral stability. Clin Orthop Relat Res. 2006 Jul;448:157-63.