Thank you Barb.

You saved me $40 again. "Who is Barb and how did she save you $40?", you ask. Barb is a pediatric nurse practitioner/friend of mine from CT. Back in the day she showed me a quick and easy way to reduce nursemaid's elbow. Three times since she showed me I have been able to take care of the subluxated elbow without a trip to pediatrician or ER. To save myself nasty comments in my box scolding me for giving out advice I'll just say if your kids are prone to this as mine are, ask your doc to show you how to reduce it, my pediatrician in CT assumed I knew how to do it. Not having to go to the doc or ER significantly shortens the duration of your child's pain, takes away the risk of being exposed to something nasty, and saves you a lot of time, trouble and $$. It is so..so easy.
And lastly, nursemaid's elbow is really a misnomer it should be called 'stubborn toddler' or 'roughhousing sibling' elbow, in my opinion.

Definition of nursemaid's elbow for those who haven't a CLUE what I am talking about :D

*****Nursemaid's Elbow
Nursemaid's elbow is a common injury that is seen most often in children between the ages of 1-3 years . Usually the child has had an incident in which the extended arm was pulled. Most commonly it occurs when a child is falling and the individual holding the hand doesn't let go. Another common mechanism is when the child is swinging while being held by the hands. Occasionally, the injury occurs after a fall.

Anatomy

Nursemaids elbow is an interposition of the annular ligament into the radial-humerus joint. The annular ligament normally passes around the proximal radius just below the radial head. With traction on the extended arm, the annular ligament slides over the head of the radius into the joint space and becomes entrapped.

Epidemiology

Nursemaid's elbow is more common in girls than boys and more often on the left side.
Usually between 1-3 years of age and rare after age 4.
Child will not use the arm and holds the arm slightly flexed and pronated.
May elicit tenderness over the elbow joint but there is no swelling, redness, warmth, abrasions, or ecchymosis.*****

Once you have seen it it is really easy to recognize. The way a child holds their arm is very specific and the story of a yank on one arm matches.