Arnold Schwarzenegger says he's been having knee problems all his life from weightlifting, skiing, running and climbing ... and now he's sharing tips and tricks for managing the pain.
Arnold's teaming up with his physical therapist girlfriend, Heather Milligan, for a fun and informative video that just recently dropped -- and it's all about a topic he's often asked about in his Arnold's Pump Club daily newsletter ... namely, "What do I do about my knees?"
Heather's an expert in the field .