Hello, my name is Tom. For as long as I can remember, (yet somehow, I remember times like Taekwando when this wasn't a problem...couldn't have been), I have never been able to extend my elbow past about 170 to 175 degrees. Most people can go 180 to 185 degrees, but my joint literally locks there, it's not due to pains or injury. Again, in Taekwando, I don't remember ever noticing this issue, so it couldn't have been like this for more than four years or so. I'm currently almost eighteen. I'm wondering if this problem actually does have a cause, other than by birth, that I may have triggered at some point in my life without noticing or something...And if it has a solution or cure. I have well above average flexibility, and always have.