I don't get sore playing a round, but after 4-5 large buckets with my training clubs then my lower back is also sore as with many other muscle groups. Not a bad sore, as it usually goes away after a day or two as well. It's usually the next morning that the soreness kicks in. . .
Welcome to the site. I'd focus on a couple things, turning the feet out at address and turning your hips in place. The feet bit will help the turn.
Notice how your hips sway back on the backswng and you tilt your spine towards the target.
And this leads to them not being able to get forward enough on the downswing. Causes path and contact issues.
Couple good threads for you to take a look at.
Another update I want to share with everyone.
I been "chipping" with my putter and "putting" with the same putter. The only difference is chipping has a "hit" feeling with a bit of wrist break. I am more concerned about distance control then direction
when I "putt" with a putter I tend to "stroke" the ball with no feeling of a "hit" there is very little discerning wrist break. I tend to see specific line (rather than a ribbon in chipping) and a matching speed
when I putt I like to feel lifting the putter with last three fingers of my left hand primary stroking from the left hand control
when I chip I like to lift the club with the middle and right fingers at the middle knuckles and feel like the "hit" is powered by my right palm