Do you get lower back pain during or after golf?
This unfortunately is very common, but it shouldn't happen. The golf backswing and follow-through require a lot of spinal and hip rotation. The lumbar spine (lower back) is only supposed to rotate a few degrees, and most of the spine's rotation should come from the thoracic spine (upper back). Too often though, the thoracic spine is stiff and the lumbar spine ends up compensating for its lack of rotation.
Try this exercise before your next round:
1) lie on your side with a foam roller or a pillow under your top knee for support
2) open your top arm towards the ceiling or the wall behind your, keeping your eyes on your thumb (this ensures your neck rotates along with your thorax). THIS MOVEMENT SHOULD COME FROM THE UPPER BACK, NOT THE LOWER BACK OR SHOULDER
3) hold at end range for 1-2 breaths before coming back to the start position. Repeat 3-5x/side