Knee hurts

Second day of Bolex shooting at the university has really killed my knee. The groups of students go into different areas of campus to shoot where there is good light and I give them my cell number so that I can come to them to help. This is usually an exciting day full of exercise, but it turned out to be an exciting day full of pain.  I'm not sure if it is arthritis or a side effect of some antibiotics, but my right knee is almost crippled. Thank goodness Maricarmen was there to help with some of the groups.