Home Exercises:

Bridging

(Works lower abs, glutes and lower back.  Stretches abs and hip flexors.)

Lie face up with your arms by your sides, palms facing down and knees bent, with feet placed directly under knees at hips width apart. Relax your shoulders into the floor, but keep your abdominals tight.

Contract the gluteals and use your leg muscles to slowly lift your tailbone and lower to middle back off the floor. Slowly roll the spine back down to the floor, one vertebrae at a time, saving the tailbone for last. 
Repeat 10 - 12 times, three to five times per week.