ok guys with all my walking and gazelling and curving the backs of my thighs are hard as stone... the fronts however are all jiggly.... anyone out there have some front of the thigh tightening ideas...

(PS cant do squats: back issues)

Walking uphill or up stairs will hit your quads more.

And you could do exercises (leg extensions) with ankle weights or on a weight machine, too.

Walking up stairs!! That will definitely do the trick.

Since you have back issues you might want to try frontal kicks. It sounds easy and it is, but is a good way to train the quads with no weights.
Get a stool about 14 inches tall, you might want a dowel or broom or something to help you keep balanced. Stand behind the stool, place one foot on top of the stool, and in the opposite hand have your balance stick if needed, then, simply kick the leg forward with the foot flexed, but when your foot comes down to the stool, try not to touch it, or if you do, touch with just the toes very lightly and very briefly. There should be no momentum guiding these kicks, they are quick, but steady.
Now sit on top of the box, and place a dumbbell on your quad (if you want one, this can be done without as well) flex one foot, place the other on the floor, legs together. Now simply lift the leg, then press the leg out fully without touching the floor, then bring the knee back up with the quad muscle.

Dang too bad you have back problems... A few times I have done pop squats, to do this you stand with legs quite a bit apart, toes pointed out and jump, you don't even have to jump that high, so maybe you could give it a tray, when you come back down you squat down, you don't need any weights to do this... then you super set with leg extensions ... These 2 are the only exercises that make my quads burn ...

thanks guys!!!! u have given me a lot of ideas here!!!!!