Exercises to Strengthen Your Core

Back Extensions
Lie face down, legs together and extended straight, arms bent with hands behind neck, head and neck in a neutral position.
  Lift the upper body (chest, shoulders) off of the ground, "crunching" towards the hips. Hold for a count of 5. Slowly lower to floor. Repeat 3 times.  You can also do this as the picture shows, just up and down for a count of 5.  I prefer holding it for a count of 5 and then lowering.  Either is okay. This is a very small movement-- don't move further than you can naturally and easily.

 Plank
Begin this exercise by lying on your stomach with your forearms on the floor pointing straight forward, your feet together and your spine in a neutral position. Your feet should be touching or no more than an inch apart. Lift your body up on your forearms and toes, keeping your body as straight as possible. Maintain this position for as long as possible and challenge yourself to longer periods in the plank position. Try to hold the position for 60 seconds. Don’t let your hips/knees drop, your butt raise, or shift weight to one forearm.

                                                                                                            
   Airplane Pose
Stand with feet together, arms at sides, and gaze at a spot on the ground about 5 feet ahead for balance.  Lift left foot back, bending forward until left leg and chest are almost parallel to the ground. Extend arms out as shown. I prefer to hold the pose as you bend over slightly for a count of 10, instead of going up and down as the picture shows.  I think it improves balance more doing it that way. Concentrate on centering yourself as you bend over slightly.  Remember to do the opposite leg.  Repeat for 2-3 sets. Don't worry about trying to go as parallel as she does in the picture.

  Banana Pose
Lie on floor with legs together, arms extended overhead, belly button pulled in toward spine. Keeping head between arms, slowly raise upper body and legs off floor to form a gentle banana like curve. Hold for a count of 10. Then lower. Repeat 3-4 times.

    Ball Crunches   
I like to do these with my feet  (toes) touching a wall to keep from sliding.

Begin by sitting on top of the Swiss ball. Roll in the direction your head is pointed until your lower back is supported by the curve of the ball. You can either cross your arms over your chest or place your hands behind your ears. Do not put them behind the head or clasp them together behind your head. Crunch forward, using your abdominals, until you are at approximately a 45 degree angle to the ball. Keep you neck in a neutral position. Try doing 3 sets of 15 crunches.Your lower back should feel supported while doing these.

                                                  
Twist Crunch  
Lie on the floor or a mat on your back, with knees bent and hands behind head. Feet should be flat on the ground. Keep a space between your chin and chest (looking diagonal towards the ceiling). EXHALE: As you lift up, rotate upper body toward one side, then rotate back to center. INHALE: Lower your back to the floor. Alternate sides. 10 reps each side. Repeat 3 times.