To our crossfit brothers and sisters, I write this blog not to blame, nor to discourage future ventures and activity. Rather as an update and a readjustment. Science has reached its status by constantly adjusting its view based on what is observed, and we have observed shoulder injuries with cross-fit training. CrossFit training involves shoulder mechanics as much, if not more, than any other form of exercise. In the last two years whislt working with CrossFit athletes, I’ve seen biceps tendonitis, impingement, rotator cuff issues, and labral tears. The structures are housed closely together and dysfunction in one affects function in the other. But why does all this happen?
To start with, let’s review the anatomy of the shoulders. Look right!
The elbow has the biceps and triceps working in a simple harmonious relationship. Easy. The shoulder however is a little more complicated. Let’s concentrate on rotational movements. The pec major and minor and the latissimus dorsi are the large, strong internal rotators and battling them are the rhomboids and lower traps (when talking specifically about shoulder blade movement). Lot's of muscles all trying to stabilise the shoulder during various different movements.
The pec minor, when tight, can pull the shoulder blade into a protracted and downwardly rotated position. Not good. The latissimus dorsi attaches to the front of the upper arm bone and is commonly trained as a back muscle due to its origin at the lower back. However, because it travels underneath the arm, as it contracts, it internally rotates the shoulder. These two muscles combined give the rounded looking shoulder.
But why is this functionally poor? Within the shoulder joint are bursas, tendons, ligaments and the capsule. Essentially to much internal rotation decreases the space inside the shoulder. If weight bearing is added, for example chest flies/shoulder press, overhead squats, then the risk of ‘impingement’ of any one of these structures is increased.
Standard push ups, handstand push ups, push press, push jerk, kipping pull ups, hang power clean, hang power snatch, ring dips, overhead squatting are all exercises that the crossfit box loves, however are very stressful on the shoulder. CrossFit athletes often have highly developed deltoids by the nature of their sport, which counteracts the stabilizing action of the rotator cuff. If you don’t have proper scapular positioning and proper stabilizing strength throughout the rotator cuff and scapula then it is only a matter of time before that dreaded injury occurs.
The labrum is not to be forgotten in this complex flow of shoulder movement and mobility during your daily crossfit WOD. Often injured in overhead throwing athletes, the labrum provides additional stability to the shoulder joint, with the assistance from the rotator cuff muscles. When the cuff is weak, the biceps tendon and labrum will take up the slack, attempting to provide additional stability. When the rotator cuff is already weak, and then gets fatigued with a kipping movement, the labrum takes over. Because of it’s low tensile strength, something has to give. Unfortunately the labrum normally ends up as the casualty of war. A major shoulder injury will set you back 4-5 months of training. Do you really want this?
So how do we fix this? Well that deserves a blog on it's own. So watch this space. For the time being this article on progressing overhead work is helpful (only for the injury free folks sorry). Also this awesome blog looks at overhead squat tecnhnue in the shoulder.
Enjoy your next WOD
S D J Morgan and Andrew Ross