Stretching for flexibility.Kickboxing takes flexibility. you might have to stretch some.
PSOAS!!! The source of back pain. This muscle attaches to your lower spine and to your thigh bone. If it's tight (sitting too much?) it pulls your lower back. It's ONE of the common causes of lower back pain! If you can stretch this regularly then your lower back may feel a lot better! (makes your tummy look a bit flatter too.) ;)