Rectus abdominis, obliques.
The curl-up involves flexion of the thoracic spine, lifting the weight of the shoulders and head using the rectus abdominis assisted by obliques.
The advantage of the ball is that the thoracic spine can work through a greater range of motion, starting from slightly extended through to fully flexed. This only works if the exerciser can fix the lumbar spine by keeping the pelvis still, relative to the ball.
In addition, the second aim of correct technique is to ensure that the shoulders and neck do not assist the abdominals.
A way of progressing the loading and demands of the standard ab curl exercise (as load and range of motion are increased). Useful for sports-specific training for advanced core strength or at the end of a rehabilitation programme for a core stability progression.
Strong exercisers with no low back symptoms.
- Lie on your back on the ball. Knees bent and feet comfortably flat on the floor, shoulder-width apart for stability.
- Adjust your pelvis so your lumbar spine is in the neutral position, squeeze your gluteals and engage your deep abdominals (pelvic floor) to lock this position tightly.
- Lift your head slightly and bring your chin towards your chest. Fix your neck position as though you’re holding an apple between your chin and neck.
- Place your hands to your ears and open your arms so your elbows point to the side. Fix this arm position as well.
- Slowly, focusing on your abdominals, curl your upper back off the ball. Do not move any other body part, keeping your arms, shoulders and neck and legs relaxed as the abs pull you up.
- If done correctly, your head and arms will curl up as one unit with your shoulders.
- Maintain the gluteal and pelvic floor squeeze to keep your pelvis in neutral and to prevent it moving down the ball.
- Pause for one count at the top.
- Slowly, again focusing on the abdominals, lower your upper back down until it is slightly extended.
- Do not move your head or arms. You should return to exactly the same position as you started.
- Keep the lumbar spine fixed in position.
Sets and reps
Eliminating movement around the ball and keeping your head still, makes the exercise significantly more difficult. Start with sets of 10 repetitions and progress to 20 reps. Once you can achieve three sets of 20, you may need to add weight to progress. You can hold a dumbbell behind your head (again ensuring you do not lift with your arms) to add load to the curl-up.