This is a bit long, but it works - from the kayakers... A "dislocation" is a joint injury where the end of a bone in the joint ends up out of place. The cause is usually a combination of the right forces and the right position, at (of course) the wrong time. For the shoulder, a "ball in socket" joint, the further the joint is open (i.e. the arm is out away or "abducted" from the body) and externally rotated (palm of hand is forward as in throwing a baseball), the weaker and more vulnerable it is. Any abrupt, intense force against the arm in this position extending it too far back can cause the "ball" to pop out, usually in front of or "anterior" to the socket. So now imagine yourself on the river and someone may have just dislocated a shoulder. How do you know it's dislocated and not broken? The answer is often easy. The victim will probably tell you. It's like having an underwear wedgie; they just know things aren't where they're supposed to be. And frequently, they "felt it pop out." This is especially true if they've ever dislocated before. Anyone who's ever had one is at higher risk to do it again, and if they say, "it's out again," believe them. Suppose all they do is scream and tell you nothing. Remember that the mechanism is important. Any force pushing the arm back while its abducted and externally rotated (again, as in a throwing position), a dislocation is much more likely. Falling directly against the arm or shoulder while the arm is held against the body usually results in bruising or a broken bone, not a dislocation. There is no crunching or grating of bone against bone (crepitus) as in fractures, and dislocations cause extreme, unrelenting pain. The pain, in contrast to fractures, often doesn't improve much even without moving and splinting the arm. Looking at the shoulder will also give you more clues as to the type of injury. Before swelling sets in and on thinner individuals, the dislocated shoulder looks different. It will have a "squared-off" appearance. To appreciate this, you need to look at both shoulders for comparison. Remove the shirt. There will seem to be a small hollow underneath the bony shelf of the shoulder. Look at how the arm is being held. For dislocations, the arm is usually held away from the body, where with fractures it's often braced directly against the body. To try to make a person hold it otherwise or move it, frequently results in slurry of naughty words. So, the shoulder looks out and it feels out. What could be worse? Imagine it's you, and you're alone. Now what? Speed is crucial. The sooner it's put back in place, the better. Joints hate being out of place, and the longer they remain out, the harder they are to put back. Plus, they'll often get even with you for long delays by giving you arthritis down the river. Enter the Kayaker Special. This is the quickest, easiest and most effective way to reduce a dislocated shoulder in the field. Plus, it can be performed by the injured person alone - even in turbulent water. It's simply done by sitting (or floating) and tucking the knees up to the chest. Lock both hands together in front of the knees as if to hug the legs to the chest. Now relax. That's right, relax, and lean back. Let the weight of the upper body do the work. With the arms locked around the legs traction is put on the arm and transmitted to the shoulder, this then pulls the shoulder back into place. Pushing out with the knees against the locked hands can increase the traction if needed. It's that simple. There are plenty of other methods to reduce shoulder dislocations, from dangling weights off the injured arm, to someone pulling on the arm with a foot in the victim's armpit for leverage. Unfortunately, these can take a lot more time, need assistance, and are often really hard torture to get a sober person to volunteer for. Fortunately, the Kayaker's Special is a lot less traumatic. It also probably has the best margin of error that allows you to not do further damage to the shoulder if you guessed wrong and were actually dealing with a fracture. How effective is it? Reportedly 97%! (Hey, if this doesn't work, the others probably won't either. That's why I left them out.) How do you know the shoulder is back in place? Usually there is a "pop" as it slides over the socket rim and back into place. The deformity corrects and there is immediate relief of the majority of the pain. Gentle rotation of the arm will confirm normal gliding of the joint. If so, check that the wrist pulse is good, and that movement of the hand and fingers is OK. Also make sure sensation to light touch over the shoulder and arm is intact. If there is a problem with any of these, an evacuation is needed, pronto. If there is no problem, put the arm in a sling. A person can stay with the trip, but the arm is down for the count, at least 1-2 weeks. This means everything, especially lifting the arm! Wrapping the arm against the body ("swathing") adds another layer of bondage for those who insist on trying to move it. The rest is up to time and the healing powers of Mother Nature. As soon as you get off the river, a follow-up with an orthopedic doctor should be done, x-rays should be taken and further treatment determined.