Written by professional physiotherapist - James Morgan.
Psoas- ring any bells? Gemellus Superior and inferior- heard of them? Obturator Internus and Externus? Quadratus Femoris sound familiar? How about the rotator cuff? Chances are all of the above might as well be made up (they are in fact muscles around the hip), except that is for the rotator cuff... My point is most people who have been training for any length of time even if they have no knowledge of anatomy and physiology have heard of this thing called the rotator cuff. Why is that a group of muscles who's existence is normally only known to those of us in the rehab/medical world is also known to the majority of gym goers? Because problems with the rotator cuff are common, so common in fact that I would estimate that 8 out of 10 people who have lifted weights for more than a couple years have had some sort of shoulder trouble, what's more, it seems accepted that this is something to be expected with weight training. So if you lift weights is it inevitable that you will at some point have deal with shoulder pain? No!... Not if you train intelligently.
The shoulder joint is a shallow ball and socket joint that is inherently unstable. The ball is actually bigger than the socket, it is this which gives us such a massive range of movement to enable us to put our hand anywhere in space, but we pay for the large amount of mobility with instability and therefore risk of something going wrong. Most joints have a high degree of passive stability provided by their capsules, ligaments and just the shape of the joint surfaces (think about the hip joint and how the ball is completely surrounded by the socket). The shoulder, however, depends more on the active stability that is provided by muscles.... which brings us to the rotator cuff. When the arm moves away from the side of the body the joint stability is provided by the rotator cuff alone.
The rotator cuff is made up of a group of muscles that originate from the scapular (shoulder blade) and attach to the upper part of the arm (humerus) as the four muscles become tendons they travel under the boney arch of the shoulder in the space between the ball of the humerus and the ‘cap’ of the shoulder, this called the subacromial space. They attach in an arc or cuff around the top of the humerus- hence the name.
Tendinitis of the rotator cuff muscles is common, both through trauma and as a result of overuse. Common examples of overuse include excessive repetitions on single weight training exercise, or poor technique over time resulting in development of muscle imbalance and excessive strain on the cuff. Whereas trauma may be the result of an ill timed wrenching action which involves rotation of the shoulder joint.
I’m going to deal with overuse; where abnormal strain or repetitive compression is put through the cuff again and again, weakening it until eventually its function becomes compromised and damage to the structure of the fibers occur. The gradual breakdown is called a tendonopathy when it gets inflamed its called a tendonitis.
Here are my observations of how problems with the rotator cuff come about:
‘Robot training’- what I mean by this is most bodybuilders and weight trainers treat the body like a machine- they break down the muscles and movements and train them in turn. Makes sense right? but the human body is infinitely more complex than any machine the brain doesn't think ‘contract middle fibers of deltoid followed by long head of triceps’ it just thinks ‘push’. Far too often I see trainers forcing unnatural movement patterns that cause undue strain on the rotator cuff. An example of this is lateral raises performed taking the hand straight out to the side (abduction). How many times have you performed this movement outside the gym? The more natural plane of movement is something called the scapular plane...google it..its somewhere in-between a front raise and a side raise, think about when your reach for something above shoulder like a cupboard or shelf ....think about where your elbow is it relationship to your shoulder (you can put your arm down now!)
Another aspect of robot training is over reliance on machines like seated shoulder press or smith machine press I know you have heard this before; using a machine forces you to move the weight in a ‘one size fits all’ movement plane.
Going too deep- There is little benefit in shoulder pressing when you lower your arms all the way down yet there a massive compression/strain on the cuff. When lifting big weights above your head I recommend never letting the elbows go below shoulder height. If you then want a more ‘full range’ exercise I recommend arnold press- its a much more natural movement pattern that involves several combined movements.
Going heavy all the time- Any time you lift heavy weights above your head or out to the side with a long lever there will be inevitably be huge forces going through the cuff. A lot of trainers can get obsessed with the numbers with regard to weight lifted. Your muscles don’t get bigger and stronger from weight, they get grow in response to tension; obviously there is a correlation in weight lifted and the tension put through the muscle but good exercise choice will put maximum tension through the deltoid with minimum strain through the shoulder joint. I also recommend throwing in pre-exhaust sessions here and there. Instead of jumping straight to the heavy presses while you are fresh. An example would be to perform super sets of lateral raises (in the scapular plane!) with upright rows before performing shoulder presses...you will not be able to lift anywhere near as when you are fresh but you would of have taken your delts to failure without having to put as much stress through the rotator cuff.
Failing to include variety- Performing the same routine again and again and again is a sure fire why to develop muscle imbalances which results in altered pull of movement muscles which makes stability muscles like the rotator cuff work harder and puts uneven stress through the joint.
Poor form- A danger of poor technique in shoulder training is the possibility of causing compression or squashing of the rotator cuff on the under side of the subacromial arch, if this happens enough times it has the potential to cause micro trauma which can eventually lead to a tendonopathy. I have already mentioned lateral raises, so if you are training with a weight that is too heavy, or not controlling the weight, or performing ‘un-natural’ movement patterns there is a risk of micro trauma to the cuff.
Continually upgrading horse power while ignoring cornering and suspension- Even if a weight trainer avoids falling into the traps above there is still a risk of a rotator cuff injury occurring if specific rotator cuff and stability exercises are not added to shoulder training. Put it like this; if you put more and more horse power in a race car yet do not upgrade the brakes and suspension accordingly then the car may be fast in a straight line but as soon as it comes to a corner it will be unable to control the power and spin off the track (injury!). In the shoulder, part of the rotator cuffs job is to control the force exerted by deltoid. The deltoid muscle pulls the arm out to the side but as it does this it also causes an upward glide of the ball of the humerus (the humeral head). It is the job of the rotator cuff to oppose this upward glide, otherwise the head of the humerus would buttress up again the subacromial arch. If you work on your delts and they get stronger and stronger (horsepower) with no rotator cuff training you can cause a strength imbalance between the cuff and deltoid. The rotator cuff may actually weaken during this process as with no specific training it may struggle to cope with deltoid’s power, it gets over worked and fatigued, as it does so more gliding of the humeral head occurs. The cuff has to work harder again to try and control the extra glide and it becomes fatigued further still and eventually a tendonopathy develops. I have assessed people who can shoulder press huge weights but when I do some specific cuff strength tests I can overcome them with 2 fingers.
In the second article on the rotator cuff I will answer any questions you may have and make some suggestions of exercises to strengthen the rotator cuff and guard against shoulder injury while also potentially improving your lifts.