Sore Back

[canadaump6]

I did my second plate game of the year today, and although it was only 7 innings, I found myself having a stiff lower back by the fifth inning. I mentioned this to my partner, who suggested I stay standing a bit longer before dropping down into my stance. I tried doing this a few times and it really helped my back, but I eventually decided I had better stay with what I has been doing for the majority of the game which was bending the knees a little bit, then as the pitcher starts to pitch leaning forward at the waist thus being in my stance. Do any of you ever get a sore back? Is it okay or normal to have this happen?