Hi Christine Mary,
I want to say yes, to having joint pain and it being caused by Herceptin. And it is just as you described after resting for a long period time is when I feel it. I was just joking with my Ob/Gyn that when I get up from sitting or sleeping in the morning, I feel like a 90 year old lady. I can say, I am definetly experiencing what you describe and have been solely on Herceptin since July of 2010. And like you, once I am off of it, I am really banking on being able to not have to crouch when I get up from a resting position. It's terrible...I agree. But...a small, small price to pay to be well again.
Take Care