Lower Back Problems

Hi, and first of all, sorry for my English.

I am a 17 year old boy who have been training Tae Kwon-Do for 9 years and on the junior national team. I have been lifting weights for several years and is confident in my lifting techniques.
But this last year I have had problems with my lower back.

I have gone to a Naprapath the last year but all I found out there is that my lower back have a habit of latching when I kick. I have been to my panel doctor and had a x-ray of my back but did not find anything. The only advise I have gotten is to train core and stabilizing muscles in my lower back and abdomen. I have a Red Cord set up at home and access to a good gym.

The reason that I am here is because I have some exercises I use, but I don’t feel that they are helping.

The exercises I use is superman in red cord, plank in red cord, sumo deadlift, and frontal squats.

In addition I do push ups and leg curls in red cord.

PS. My doc said there was a chance for something called “Kissing spine”

Do anyone out the have a similar problem or does anyone have some good exercises that might help?

In advance, Thanks

Red Cord is the same as a T-Rex setup. In other words to adjustable handles hanging down from the ceiling.