If you've ever had a sore shoulder or have had the horrible misfortune of suffering through a Frozen Shoulder these (hilarious) "T-Rex Trying" pictures hit pretty close to home.
Last one, promise.
Frozen shoulder - or the fancy clinical name "Adhesive capsulitis" is a disabling disorder of the shoulder capsule and the connective tissue surrounding the shoulder (glenohumeral joint - which will now be referred to as GHJ from now on). Which causes the GHJ to become stiff and inflamed which will also cause great restriction, limiting most movements and causing chronic pain. The pain is usually constant but can be worse at night and they hate being cold, even though the name suggests otherwise.
The actual cause of Frozen Shoulder is actually still not completely understood (weird, yes?). About 50% seem to stem from an injury to the GHJ (like a fall broken with an outstretched arm, post surgery to the GHJ, untreated biceps or triceps tendinitis) these are called secondary frozen shoulders. The other 50% just appear with no rhyme or reason and these are called primary frozen shoulders. And at least in it's idiopathic form (arrises spontaneously) this is 70% more prevalent in the female population than the male population and will usually effect women ages 40-70 years of age. But enough of the doom and gloom, if you've had this once, it very rarely comes back again.
Now for an anatomy lesson, yaaay!
SHOULDER ANATOMY
The shoulder is a modified ball in socket joint, with the top part of the arm bone (humerus) being the ball and the shallow cup on the end of the shoulder blade (scapula) being the socket. This is the best design to give maximum mobility to the shoulder, but it also makes it super unstable. To improve the instability 4 muscles (called the rotator cuff) and a wad of tough internal ligaments come to the rescue.
Surrounding the GHJ is a little bag called the capsule. If you were to raise your arm above your head, the capsule becomes fully stretched, and when the arm is lowered back to the side of the body the capsule hangs down in a little sack (called the plica). Inside this capsule is a little bursa that is filled with synovial fluid (like WD-40 for your joints) this capsule contains up to 60ml of synovial fluid. The fluid helps the joint move without pain and also gives the joint surface nutrients for repairs.
CHRONIC INFLAMMATION & STICKY CAPSULE
Once the shoulder becomes "frozen" that small sack that contains the synovial fluid will shrink and begin to stick to itself, as this stickiness occurs the synovial fluid drains away to about 5ml, now you have that dry crackly joint happening. Crunch. This sticky cracky frenzy is brought on through massive amounts of localised inflammation and more inflammation spreading to other soft tissues through the shoulder girdle.When Frozen Shoulder occurs arthroscopic cameras have shown these bursae to shrink down to half their normal size. The shoulder isn't a massive joint, so there isn't a lot of space kicking around in there, so once that inflammation starts thousands of microscopic cells of inflammation can easily make their way from sheath to sheath till eventually the entire shoulder joint becomes surrounded in this huge inflammatory cycle.
The nature of inflammation/swelling isn't a bad thing, this is a natural healing mechanism your body does. But sometimes the place being inflamed doesn't get the memo that it's supposed to be healing itself. Swelling/inflammation always feels worse at night or as soon as you wake up. Once you start to get the joint moving the swelling will dissipate and the pain will reduce.
There are 2 types of inflammation: Acute and chronic. Acute, for example is when you are happily jogging down the local running track, hit a tiny divot in the dirt and your ankle folds in half causing it to rapidly swell and diminish over the next 72 hours (not speaking from experience...#clumsy). And then there's chronic, which lasts much longer than 72 hours. Once this type of inflammation starts it will fester for months on end. In the case of Frozen Shoulders there is some acute inflammation, but unfortunately chronic inflammation is the major player at work.
MUSCLE WASTING
Once the swelling and inflammation spread through the GHJ the arm movements will rapidly diminish. Within a few weeks, the arm becomes frozen and cannot be raised more than 50 degrees in any direction (normal ROM function is 180 degrees front, back side to side). Your muscles throughout the rotator cuff (Supraspinatus, Infraspinatus, Teres minor, Subscapularis) become weak and will slowly start to waste. With the muscle wasting happening rapidly it cannot be chalked up to lack of use. Again, the muscle wasting in the frozen shoulder is not fully understood and can be a result of a neurological phenomenon. I believe it has to do with the inflammation and lack of circulation that is happening within the GHJ, the lack of nutrients causes the wasting in the same way the muscle rapidly wastes when a arm (for example) is broken.
SUMMARY
The worst part about Frozen Shoulder Syndrome are the set backs. One you start making a bit of headway, the smallest set back can trigger the entire process to start over again. Remember when we were talking about acute and chronic inflammation? Anti-inflammatories are fantastic at treat inflammation/swelling in it's acute stage but not so good in the chronic stage. Manual therapy, and exercise are the best treatments for this. It may all sound quite depressing, but do know it is fixable, you just need to be proactive about it. It isn't something that will fix quickly on its own. Talk to your Physiotherapist and set up sessions with a physio then see a qualified remedial massage therapist for manual therapy after your physio sessions.
Below are some great links for exercises to get you going - As always check with your health care provider to make sure these exercises are right for you.