When it comes to thinner thighs
, there's no exercise better than a squat.
Here's how you do it:
1. Place an exercise ball between the wall and the curve of your lower back.
2. Stand with your feet shoulder-width apart.
3. Bend your knees and lower 5 to 10 inches, keeping your shoulders level and your hips square. Hold this position for 3 seconds and then stand back up.
4. Start with 5 reps and work up to 12. Rest for 30 seconds and do another set.
I believe that having your legs in shape will affect the back. This is because the thighs are very close to the lumbar. Plus this exercise has to do with maintaing a straight back.