Abs exercise
Stability Ball CrunchHow to do it, with form in numbers
- Main muscles
- Abs
- Equipment
- Stability ball
- Level
- Beginner
How to do it
How do you do the Stability Ball Crunch?
- Sit on the ball, walk your feet forward and lie back until your mid-back rests on it.
- Set your feet flat and hip-width apart with your knees bent at a right angle.
- Cross your hands on your chest and breathe out as you curl your upper back off the ball.
- Pause, then lower slowly back over the ball.
Cues
- Ribs towards hips.
- Lower back stays on the ball.
- Feet planted, ball still.
Common mistakes
- Sitting all the way up: stop once your upper back clears the ball.
- Hips dropping: keep your thighs level with the floor.
- Wobbling: widen your feet a little for balance.
Form in detail
What does good form look like?
The version in our demo
Crunch with the mid-back on a stability ball, feet flat, hands crossed on the chest.
Starting position
Sitting on a properly inflated ball sized so the thighs are level when seated (it sinks about 15 cm under body weight), then walking the feet forward and leaning back until the mid-back rests on top of the ball and the hips sit just in front of and below the top. Knees bent 90° with the thighs about level with the floor, feet flat and hip-width apart, toes forward. Trunk roughly level with the floor, following the curve of the ball. Hands crossed on the chest, head in line with the spine.
The movement
Tuck the chin slightly and curl the upper trunk up, drawing the bottom of the ribcage towards the pelvis until the upper back lifts off the ball. Hold briefly, then uncurl slowly back over the ball. The tailbone and lower back stay on the ball, the feet stay planted and the ball does not roll.
Breathing
Breathe out as you curl up, in as you lower.
Tempo
1.5 s up, 1 s hold, 2 s down (4.5 s).
Form in numbers
What are the angles and distances?
- Knee flexion 90°, thighs about level with the floor, hips level with the knees (ACE).
- Lower back and tailbone keep contact with the ball; hips do not rise or drop.
- Chin about a fist's width from the chest.
The targets our 3D demo was built to, from the references below. Bodies differ, so treat the ranges as a guide for your own build.
For coaches
Use this demo in your clients’ programs
The Stability Ball Crunch is in Trainaq’s exercise library. Add it to a workout, and your client sees this demo in the free Trainaq app above the sets they log.
Sources
