This is something that I am struggling with at the moment.
I have had lower back problems sinse my 30s, actually its my hips that that cause my lower back to overcompensate. At 40 I had the great idea to begin Karate. At the start it was quite painful to kick but nowadays with all the excerise and daily stretches my back is a lot better and I have reasonable flexibility.
The problem seems to be that my body has not realised yet that a kick is no longer followed by a jolt of pain and I still tense up, which results in an awkard kick and that does effect my confidence in kicking and ironically hurts my back.
I am making an effort to spend time practicing all kicks more including jumpng and spinning kicks, both on the bag and in free air. This is working but any suggestions on tips or exercises I could try would be appreciated.