What Causes Muscle Tightness In Calf And Leg Weakness?

I have L 5 s1 s2 problems. Initial onset was severe sciatic pain down left leg. I couldn't stand, walk, lay, or sit. After the pain subsided, I had intense muscle tightness in left calf causing me to limp. Attempted my stretches from PT previous year which did nothing. Currently in PT, seeing some improvement, however, I have leg weakness and do not have much endurance. Leg fatigues quickly. I have MRI scheduled for Monday. Any thoughts?