Once you feel that the traditional crunch is no longer necessary, move on to the Jackknife. Your rectus abdominis is the main target muscle during this move. It is located on the front end of your abdomen, also known as your “six packs.” There are many variations of the jackknife exercise, which may challenge core muscles more than traditional abdominal exercises.
Muscles Worked
You can do a simple jackknife exercise sitting up on the ground, but your rectus abdominis will be the target muscle. To complete the move, you will also need your obliques and muscles in your chest, thighs, gluteus and calves. You can also use a power wheel, or a stability ball to help you recruit more muscle.
Medical Research
There are so many opinions on the best abdominal exercise. It can be hard to decide which one is right. In 2009, a study was published in “Journal of Bodywork and Movement Therapy”. It examined four abdominal exercises: the Swiss ball rollout, Swiss ball curlup and Swiss ball jackknife exercise. The results of muscle activity Petite Yoga Pants tests in the upper and lower regions of the rectus abdominis were positive. Moves that were done on a stability ball showed stronger activity. The most effective move to target your lower rectus abdominalis or lower stomach was the jackknife.
Proper Form
A stability ball is a great way to maximize the benefits from the Jackknife exercise. Start by placing your hands on the ground supporting your upper body. Next, move your hands forward so that your shins are on top of the stability ball. Place your hands on the floor and place them in a plank so that your wrists, elbows, and shoulders form a straight line. Bend your hips, bend your knees, and bring your knees towards your chest. You will simultaneously pull the ball towards your chest with your shins. Move forward until your heels touch your buttocks. Then, return to the original position and continue.
Take Into Account
The stability ball jackknife exercise can be considered an advanced move. Make sure to learn other basic moves first. To make the move easier, don’t lift your hips. Instead, tuck your knees into the chest when you first start using the ball. To perform a basic jackknife you can lie on your back, with your hands at your sides. As you raise your torso, bend your hips and knees while bringing your thighs towards your chest. Reverse the motion and return to the original position.