Hello, so I am a 26 year old female. Randomly for the past 5 years, my knee randomly locks up on me, the knee it occurs in varies everytime. It generally locks up on me in the process of standing up or sitting down, as well as getting in and out of my vehicle. It locks up usually between just a few minutes, with the longest being 40 minutes. During that time I am unable to move it in any which way without severe pain. However, my fingers this past year have been doing the same. My shoulders and my shoulder bone are always sore. I'm use to the pain most of the time, but occasionally it will last for days even a few weeks before a area will calm down from a throbbing state. Is this a sign for arthritis or is there something else I should be looking towards?