My Elbows And Knees Skin Feel Tight And Have A

My elbows and knees skin feel tight and have a burning sensation. It hurts to kneel even onto a soft surface like a bed. When I squat and my jeans pull tight on my knees, it hurts. Also, when I wear a jacket and bend my arms, the pressure of the jacket hurts. What is this? I don't like this pain.

Other info. I am a 52 yo male with Type 2 diabetes.