Common Crossfit Injuries: Shoulder Impingement Part 1

What is shoulder impingement? Why do shoulder impingements occur? How to strengthen shoulder external rotators.

Understanding the common causes of shoulder injuries is the first step in building an effective strategy to get you back to full shoulder health. We look at the common causes of shoulder impingements, and what coaches, athletes and therapists can change to speed up the recovery process.
If you would prefer to just look at shoulder strengthening exercises, including rotator cuff exercises and shoulder stability exercises jump straight to part 2:

How to treat shoulder impingement

Q. What do all the following movements have in common? Push press, shoulder press, jerk, snatch, overhead squat, pull ups, kettlebell swings.
A. They’re all movements that involve going overhead and in CrossFit this might be under significant load and/or for multiple reps.
Shoulder impingement has got to be one of the most common injuries I see and treat in CrossFit athletes (definitely in the top 5 with lower back pain) but fear not! This condition is very preventable if you know what the predisposing factors are and how to systematically address them. In this article I’ll be providing some insight in identifying some of the common culprits of impingement syndrome and giving you the tools to treat them in the next part. So take my hand reader and I will show you the way to pain free overhead glory!

WHAT IS SHOULDER IMPINGEMENT?

Essentially shoulder impingement is a catching of one or more of the soft tissue structures that live between the acromion and the humeral head (Peterson and Renström, 2001).
I think it’s worth pointing out two major points of relevance here. First the shoulder is built for mobility, not stability and that this relationship is inversely proportional i.e. the more mobile a joint is, the less stable it is. But the sacrifice of stability does not come without its perks. Throwing, going overhead, reaching behind your back, the freedom of movement available at your shoulder is considerable when you think about how hard it would be to do an equivalent ‘skin the cat’ with your hip joints (apologies to the non-crossfitters who will not understand this inside joke).
Second, the subacromial space (posh talk for space below the acromion) is limited at the best of times, so it’s not hard for it to become clogged up. Inflammation, thickened ligaments or tendons secondary to overuse or tears, super tight pecs and/or lats, all ways that can reduce the space in your shoulder joint and make you more susceptible to impingement.

‘Find out how Crossfit Games masters athlete overcame her shoulder impingement & elbow tendinitis – Cathy Wilson’s full story  

Please note due to the scope of this article below is not an exhaustive list of the causes for shoulder impingement. There are MANY more ways that can lead to impingement and often athletes present with multi-factorial causes that require in depth subjective and objective assessment to figure out.

Aetiological Factors

Primary Causes of Shoulder Impingement – (The things you were born with)

1) The shape of your acromion: This bone forms the anatomical top shelf of your shoulder. If it’s shaped like Captain Hook (not the man obviously) you’re more likely to catch the underlying structures when going over head. This can also be a problem if you have bony growth or osteophyte formation protruding out.
Solution: Ensuring joint health through proper nutrition and supplementation (such as GLC2000) is good way to try and avoid undue degenerative changes in the articular surfaces of your joints, but fraid there’s nothing you can do about this one if yourself. An x-ray will show if you have this problem and whether surgical invention is required.

Secondary Causes of Shoulder Impingement – (The bad habits you’ve picked up)

1) Over-activity of the ‘terrible trio’: Poor postures and overworking certain muscle groups can lead changes in joint orientation and create a predisposition to shoulder impingement. Three muscles that are one’s to watch out for are: rhomboids, levator scapulae and pec minor. These 3 might not cause enough of a problem on their own but they work in tandem to cause downward rotation of the scapula. This can mess up the delicate timing in movement between your shoulder and shoulder blade that helps to ensure you don’t impinge while reaching overhead.
 
2) Rotator cuff weakness: The primary role of the rotator cuff muscles is to keep the head of humerus positioned in the glenoid fossa (socket) while the bigger global muscles produce joint movement. A good example of where this can go wrong is if the one or more of the rotator cuff muscles fails to keep the ‘ball in the socket’. When lifting the arm out to the side the deltoid contracts but drags the head of humerus with it, turning into a wrecking ball of impingement!

I was suffering with a shoulder impingement for over year – GLC2000 helped me relieve those symptoms within a couple of weeks’ 67 year old Heather Wynne  

 

3) Shoulder instability: If either the inert and/or contractile stabilising structures of your shoulder are damaged or dysfunctional the humeral head becomes a bit of a free spirit and if you’ve ever played pin ball you know it’s inevitable that the ball is going to hit something sooner or later. The labrum is a ring of fibrocartilage that slightly deepens the shallow socket of the shoulder to create a bit more structural stability. If it’s torn the shoulder becomes much more liable to subluxation, dislocation and impingement.
 

GLC2000 has been used to treat a huge variety of shoulder injuries read GLC2000 Customer’s Shoulder Injury Stories  

4) Poor posture: Where your thoracic spine goes, your scapula will surely follow. An increased thoracic kyphosis (often stemming from prolonged slouched sitting postures) forces the shoulder blade to assume a downwardly orientated position. The problem here is that A) tension in your joint capsule is lost forcing the rotator cuff tendons to work double time to stabilise the shoulder and B) the shoulder socket pointing down leaves less room in the already limited sub-acromial space making you more liable to impinge as you lift your arm overhead.
So now you’ve got an idea about what shoulder impingement is and some of the ways it can be caused. In part two we’ll have a cheeky gander at how to resolve some of these modifiable factors, reducing your chances of getting impinged and improving your performance overhead.
Written By J.Glover BSc (Hons) Physiotherapist MCSP

References
Peterson., L., Renström., P (2001) Sports Injuries: Their Prevention and Treatment (3rd Ed) , Taylor and Francis, UK, pp: 130-131.