In answer to your question, no.
(Most of this stuff is from Tom Kurz at )http://www.stadion.com
You do need strong legs for kicking but you need (in order of importance):
A very strong lower back (deadlifts, back extensions, goodmornings)
Very strong stomach muscles (crunches, sit-ups, reverse-crunches)
Very strong hip flexors (the main kicking muscle) (leg raises)
and of course very strong legs (squats - parallel (sets of 10 ish) and hindu (1 set of 100), lunges, adductor pull downs).
Strong calf muscles are not important.
If you do lots of fast kicks and you are not strong enought you will probably injure your back and/or knees (for starters).
So for powerful kicks, use a rational strength training programme first (If you can lift twice your body weight in deadlifts and your own bodyweight on the bar in Squats easily 10 times you can start kicking above the waist).
You can then move onto specifics, e.g. adductor pulldowns, lunges (front and side).
This in combination with a stretching workout
*dynamic stretching - morning/preworkout
*Isometric stretching - post workout
*Relaxed stretching - post workout(after isometrics).
Finally - run regularly.
When you have obtained the required flexibility and strenth, then you can start training for power.
[This message has been edited by UKfightfreak (edited 04-15-2003).]