I honestly thought she had put a tennis ball up her leggings looking at the size of it
We did the usual dance injury treatment RICE ( rest, ice, compression, elevation ) but when I'd returned an hour later from shopping it was still as bad, maybe even worse.
Oddly she had no pain, a little stab of 'uncomfortable-ness' but certainly nothing to make her flinch.
Off to see my dad who is a retired GP who, on taking one look at her instantly showed his 'concerned face' and diagnosed Osgood Schlatter Disease.
He had only seen a couple of cases many moons ago, both in boys but the treatment for both was stopping ALL physical exertion until symptoms ceased.
We instantly came home, googled it and therein frightened ourselves rigid !!
From what we have gleaned it is caused by your quadriceps muscle ( the one that runs down the front of your thigh ) which joins just below the knee to the tibia.
Active kids combined with a growth spurt cause this muscle to pull away the from where it joins the bone - hence the swelling and supposed pain.
Treatment ( cue - hysterical DD and tearful mother ) - rest, cessation of physical activity for what could be 12 months or more, painkillers and anti-inflams.
DD convinced dancing dream down the pan and I can readily admit, that even with a bottle of Sauvignon blanc I didnt sleep a wink that night.
She went into her CAT scheme at The Lowry the following day who took one look and said nonchalantly 'Oh yes, you've got OSD - we'll manage that for you' !!!
I spoke to other mums at dance and found someone else in the same dance school as my youngest DD who has it.
I went to a freestyle dance competition on Sunday with youngest DD and almost everyone I spoke to had heard about it, knew someone with it or had been warned about it !!
I was amazed - it was a LOT more common than I thought ( thanks dad for scaring me witless thinking my DD was a rare specimen ! )
So from what we can gather - its common in sport and dance and usually affects more boys than girls. Ages 10-16 combined with a growth spurt.
Treatment rest and painkillers if necessary.
GP's will tell you to stop whatever it is you are doing but there's never much chance of that as these are extra-active kids.
My DD is unlikely to rest it as much as she should but no further damage can be done if she doesn't rest it - she just might get more pain from it with the exercise and swelling under the kneecap so then we manage the pain.
We have ordered some knee pads with gel inserts for her practice sessions at dance - just to protect the sensitive swelling.
We carry a supply of Ibuprofen for emergencies and we will see tomorrow how CAT are going to manage it.
So DD is going in for her final week on the CAT scheme after her first year of being with them and if we all cross our fingers she may even be able to dance in her end of year performance at the end of this week.
So there you go - that's our OSD experience and what a scary and sudden onset it was !
Will let you know how DD gets on but seriously, thanks so much for the support.
I was really touched to read the get well soon messages and thoughts from you - meant a lot as a relative newcomer on here.
Cheers everyone xx
So he has taken a couple of months off rugby and football training and now seem much much better. We also know loads of boys that has suffered from the same thing. Good luck to your dd Im sure she will come through it and Im glad you seem much happier. 
We only want the best for our children and its such a worry when they are poorly 
