Getting a PT eval tomorrow.
My knee is often in pain and feels very unstable while I'm walking around. Also, after long walks my quads, hamstrings and calves in that particular leg get very sore/tired.
"An clicking/locking/popping?" - Yes, lots of clicking and snapping throughout the day. Usually happens very frequently in the morning after getting out of bed, and when I change direction or pivot on that foot. Sometimes just extending the knee gets some clicks/snaps too.
edit: Also I think it's more likely an injury to my ACL. I tried doing some research before posting to get some idea of what was wrong. I'm obviously a noob and probably mixed up the two ligaments.