What Is The Severe Pain And Tightness In Upper Leg During Chemotherapy?

I AM HAVING CHEMO AND AM EXPERIENCING SEVERE TIGHTENING OF THE MUSCLE IN MY UPPER LEG AND PAIN IN MY KNEE JOINT BEYOND ANYTHING I HAVE EXPERIENCED FROM MY REGULAR ARTHRITIS. IS THIS FROM THE CHEMO AND WILL IT GO AWAY AFTER I AM DONE OR AM I GOING TO BE CRIPPLED FROM THIS?