Hi there, I am a 43 yr old female and suffer from acute knee pain. Previous to this pain i had grinding of the knee but it never gave me much trouble. One night the darn cat was asleep on my right leg, so i kicked out sharply and never thought anymore about it. The next day i was fine walking, but getting up from a sitting position...and also sitting down was excruciating. Getting into the car was hellish also, seems the pain is worse when i try to put weight on it. Went to the doc's and took x-rays, she said i have arthritis in it, fair enough but why all of a sudden this pain after kicking out?? i want her to order an ultrasound or MRI, do you think this might uncover another underlying cause? Any help would be appreciated, also i'm rather overweight......Debra...