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Time to geek talk biomechanics and the spotlight is on the joint we all love to hate the shoulder and in particular the biceps tendon. As joints go this is one of the most mobile in the body. Take your arm and swing it in a big arc, scratch your back and reach up and rub the back of your head — nothing else has this versatility of movement. In return for its incredible range of motion the shoulder must sacrifice much of its stability.  If you compare it to its sister joint and fellow ball and socket team member the hip, you will see a much shallower socket with less muscular and ligamentous support around it. Remember the scene in Lethal Weapon when Mel Gibson shunts his dislocated shoulder back in? It is not often you hear about a similar manoeuvre with a hip joint.

The twenty-first century shoulder

biceps tendon

This must have needed some functional shoulder range to paint.

Unless we paint ceilings on a daily basis the twenty-first century shoulder very rarely gets a chance to express its full potential. Apart from pulling on a T-shirt in the morning and running a comb through our hair we probably do not lift our arms much above shoulder level for the rest of the day. In fact apart from getting dressed and reaching for the occasional tin of beans from the top shelf many of us actually have very little need for our evolutionary shoulder function at all. If we look at our ape ancestors and how they swung from branch to branch shoulder flexion was a massive must and a movement that was reinforced multiple times each day. The muscles around the joint got a chance to contract and stretch enabling the shoulder to find a resting place where the ball and socket was balanced and centrated and where the kinetic chain of muscle and joints above and below were also fully integrated. Is it any surprise that today’s fitness enthusiast regularly complains of shoulder pain as they dust off their upper bodies and decide to load this often compromised joint with over head pressing and the notorious bench press. Is it any surprise that surgeons are routinely shaving off bits of bone around the joint to give the most famous of the rotator cuff muscles, Supraspinatus more space to glide.

Hylobates_lar_-_Kaeng_Krachan_WB

The biceps tendon

Having set the scene lets start by dissecting a shoulder injury that plagued me in my teens and mid 20’s. The biceps tendon. Its anatomy is slightly complicated but definitely warrants an explanation as it really does help to explain why this area can cause so much discomfort.

Biceps

The tendon of the long head of biceps (pictured in red) sits at the top of the humerus (arm bone) where it nestles cosily in a groove secured by a tiny ligament called the transverse humeral ligament. It attaches up and over the humerus into the top of the shoulder socket (Glenoid Fossa) where it is prone to repetitive strain particularly in those of us who enjoy lifting heavy things over our heads. While it’s action is routinely stated as being an elbow flexor (think bicep curls), shoulder flexor (reaching up for that tin of beans) and supinator (rotating your forearm so that your palm faces upwards), it has another incredibly important role that is often forgotten. As we take our arms out to the side the long head of biceps  helps pull the head of the humerus down to stop it squashing the slim supraspinatus muscle into a bony outreach at the top of the shoulder called the Acromion. Think of it as an off balance seesaw. As the arm reaches up and away from the body the head of the humerus must glide down in the joint.

In the trenches

So how might this effect our typical gym goer. If you can find a way of shoulder pressing with your elbows facing forward that causes you less pain you might have self diagnosed yourself without realising. If the tiny ligament that secures the biceps tendon in place has been damaged then stretching it can cause the muscles associated with it to become weak (usually our friend the long head of biceps). How do we stretch it? If we assume our regular shoulder pressing position with our elbows out to the side, the tendon is stressed, the biceps become weak and hence the humerus is not secured down as the arm lifts the weight over head……ouch! The Supraspinatus is squashed with every rep we perform until inflammation kicks in, scar tissue is laid down, bursae become angry and the one chance we get to flex the shoulders during the day (putting our T-shirt on in the morning) becomes painful. What actions can stress this ligament? Putting on a ruck sack, putting your arm into your coat sleeve, brushing your hair….anything where your arms are stretched behind you.

So is the solution to take out a chisel and make more space? Sometimes this can help, but there other less invasive options that can be tried first? Most definitely.

My thought process

While getting the tool kit out and shaving off bony spurs appeals to my GCSE woodworking side (I was robbed with a B grade for my architectural forward thinking bird box), it has never really satisfied my inner detective. Why for instance would the left shoulder suffer with pain when the right side would remain unsymptomatic? Why would the shoulder pain creep on insidiously with no one instance to explain it? I always begin with a good case history and a timeline of events from which to highlight the main suspects. I then watch movement and palpate the tissues and try and piece everything together to come up with a theory, and then we tinker.

Lets take an example of a chap who came in the other day. Globally his movement was set up around a broken leg that had occurred over 20 years ago. As he walked he chose to keep it directly underneath himself and despite the heeling process having taken place many years before he still seemed to fear striding out onto it. Over time he had compensated by increasing his arm swing to help load the tissues so he could keep moving. Fast forward 20 years and we discovered an issue with that tiny transverse humeral ligament and pain on shoulder pressing. Sure enough we assessed his long head of biceps via muscle testing and it tested strong, but as soon as we took his arm out to the side in a typical shoulder press position and stressed the ligament it lost all its power. Now the solution was actually incredibly simple: a P-DTR correction to the over stressed ligament which helped the local shoulder problem then Anatomy in Motion gait retraining for the global movement issue. How did we know we were on the right track? We kept rechecking the local and global movement during the session until things started to change, then the movement treatment became the homework. It did take a couple of sessions to unravel a few more compensations that had sneaked in over the years, but that once pesky shoulder is now back in the gym playing with Kettle Bells and handstand variations as if there had never been a problem.

Shoulders are incredibly interesting joints and an area that I see a lot in clinic, so if you are a shoulder anorak like myself the next couple of posts might interest you as we continue down this path.