Hello! New driver from Toronto Canada

Hello,
I am a newly licensed AZ driver with my first driving job. I did 2 weeks with a trainer and now I will be starting my 4th week solo on Monday. I absolutely love it!! I look forward to going to work and enjoy it very much. First I do some shunting in a regular tractor for about 2 hours, then I do my run up north and switch and come home. I work about 10 to 11 hours daily.
The reason I joined Truckers Report is because I want to learn from other truckers' about their experiences trials and tribulations. I am only 5 feet 2 inches tall and the steps up to get into the truck are causing me a lot of pain in my knees. sometimes I will use the steps up to the air lines and go across to give my knees a break. I was wondering if this knee problem has to do with the fact that I am so short or does it affect tall truckers too?