Lats. Other wise known as Latisimus dorsi. Latin for "broadest muscle of your back." The ou's that paddle you round the line-up. Every stroke you take, from the second your hand grabs the water, til it pulls down to your waist, those are the lats. They're the one's that get noodle-armed when you surf a long sesh. The one's most likely to make your shoulders eina. So give 'em some love if you don't want funky shoulders keeping you out the surf.
Your Lats get hammered during paddling. They get tired, so they get tight. When they get tight your shoulders angle forward. This creates an imbalance which can create a shift in posture, and stuff up your neck, back and shoulders.
Shoulder imbalances can shrink some of the space within the shoulder joint. All that paddling tightens up the lats so you start getting compression in the subacromial space cos the muscles are pulling the joint out of proper alignment. Just like the tyres on your cabbie get worn funny if your wheels outta alignment, same thing can happen in ya shoulder.
Kak alignment grinds those lil rotator cuff tendons stukkend and leaves you with miff shoulders. The overworked lats and tight pecs tend to yank the top of your arm bone up into the shoulder socket and squish the lil tendons that run through that small gap. This flares the rotator cuff tendons up, and it becomes painful to lift your arm above shoulder level.
So, love those lats and release em if you don't wanna be kept out the surf cos of a dodgy shoulder. Gotto decompress the compression....
Doesn't help that most peeps are stuck behind a desk or computer all day - and that hunched over posture just exacerbates the shoulder imbalance. A slouched spine, rounded shoulders, and forward head posture is gonna create havoc in your shoulder joint. Just re-affirming that work is bad for your surfing!
Even if you don't have an acutely painful shoulder, you probably have some type of dysfunction or postural offset happening in there if you're surfing regularly. Which means you might run into problems down the line. Which might keep you outta the surf. Which is not a good thing.
Staying shoulder smart is pretty simple, although it does involve making the effort. All you need is a tennis ball and foam roller. They sound innocuous. They are not. When applied to your lats they become trigger point eating rottweilers. They will hurt, they might even bring tears to your eye's, but they will keep you in the water.
What you're gonna do with these guys is use em to mobilise the tight tissues, and get rid of those knots which make the muscles tight and cause all the kak to start with.
Tennis balls are great to loosen up tight pecs. Stick em on your upper outside pec area and lean into the wall and move about a bit so they rub into that area - the dude in the vid below shows ya how to do it.
Foam rollers are the perfect tool to roll out the tight spots in your lats. Lying on your side on the roller with your arm stretched out and just slowly moving up and down so the roller does it's magic along the whole length of your lats. Remember it runs right from your lower back up into the armpit, so make sure you roll right up and down.
Don't worry, you'll know when you hit the spots cos it's flipping eina. Find an eina spot then linger there a bit. The Navy slogan says pain is just weakness leaving the body.
Once you've tended to your pecs and your lats, it isn't a bad idea to chuck in a bit of thoracic mobility to counteract those long hours of slumping forward in front of the computer, desk or TV. The trick is to keep the bod balanced, so for all that forward tightness you wanna offset doing the opposite movement which is thoracic extension - see below
If you're serious about your shoulders then check out Chris Mills's site http://surfstrengthcoach.com/
He's a guru surf conditioning and strengthening coach in Aus who has some great video clips which will help you stretch and strengthen your shoulders. It's really worth looking after them cos once they crap out on you they take a while (and often a good deal of cash) to get sorted. Prevention is better than cure....