It's a hospital that specializes in treating sports injuries.

Thank you Jerome for your confirmation. Why don't they just call it seminar or workshop? The term is quite confusing for us who are not in the sport field. It was so hard to find the meaning on internet, thank you!

Thank you Katarina for your reply, yes literally seems to be something related to the medical term, but what about within this context:

"Invitation to experts to conferences, workshops or sport clinics."

I have also found that a 'Baseball clinic is a meeting at which baseball players receive special evaluation and instruction'.

However, it is still not clear for me what it really means, what kind of meeting it refers.