So I do my S&C and I lightened my load due to work, every time I come back my lower right back seizes up and it doesn't matter how much I stretch or how warmed up I get before doing 300 squats at around 100 it starts then around 200 I have to take a stop every 20 squats or so. Even when I get back into my routine I still seize up it just happens later. It does kind of act up and pop when I do kicks and 8s for my core as well. Anyone else have some advice? I've been pretty healthy my whole life but my muscles in my lower back just refuse to lighten up. Maybe someone here has some advice for me I haven't thought of yet.