A strong core helps with posture, , and can help prevent back injury and reduce existing back pain. Along with the lower back and glutes, the abdominal muscles are the primary muscle group of the core, and therefore ab exercises should be an integral part of your fitness routine to strengthen the core. However, many common ab exercises like can be tricky, and common mistakes — like pulling on the neck — can cause pain and injury.

Luckily, sit-ups and crunches aren’t the only moves that target your abdominals. There are different ab exercises to work the core from different angles and that effectively without putting undue stress on the neck and back. Personal trainer and TODAY fitness contributor Stephanie Mansour demonstrates 18 ab exercises that you can try at home: Lie down face up while keeping your shoulders and low back flat on the floor.

Keep your arms straight as you lift them up towards the sky until they are straight above your shoulders. Then, lift your legs while bending your knees into a tabletop position, stacked over your hips at a 90-degree angle. Exhale and engage the core while you lower the opposite arm and leg (left leg and right arm), hovering them above the floor.

Return to the starting position and repeat on the opposite side (right leg and left arm). Repeat five times on each side. Sit on the floor and bend your knees with your feet flat on the ground, hip-width apart.

Keep your back straight, shoulders relaxed and down, and extend both arms stra.