Hi, I've been doing thai boxing for about 3 years and my flexibility has improved very very slowly. I can't kick at all cold, feel like my lower back would give way and even when I've warmed up and done some dynamic stretching I still need to go a few rounds on the pads until I feel comfortable with my kicks. I tried to do dynamic stretching in the morning (cold) but this caused me to pull a muscle in my lower back.. I couldn't walk for about 3 days. Isometric stretching maybe the answer but I'm not sure if I'm strong enough. I do a side split stretch as part of my routine but I can’t keep my body up because it's causes a lot of pain and pressure on my lower back… would you have any clue about what this could be? The front split is a complete disaster; again pain in my lower back like it’s going to be split apart and also I feel I’m overstretching the ligaments behind my knee.