Since we had a slightly stressful evening last night dealing with this with DD#2 and ended up at the ER when our pedi had no available appts, I thought I would pass along the following info about nurse maid elbow--a not uncommon issue for kids under 2. It's really easy to treat (takes about 2 seconds literally), but when you don't know what is going on and your LO can't seem to use one of his/her arms, it's pretty unsettling, to say the least:
https://www.emedicinehealth.com/nursemaid_elbow/article_em.htm
Re: PSA re: nurse maid elbow
my best friends son had it the night beofre his first bday....2 seconds after the dr saw him...all better....
it was scary for her though!!!