Scissor kicks are an effective abdominal exercise. It is particularly useful because it can be modified to suit a beginner or expert exerciser and does not require any additional equipment. Before you try any new exercise, it is helpful to understand what muscles are being used and how to perform the exercise properly to avoid injury.
The primary muscles involved in scissor kicks are the hip flexors and the transverse abdominis, the deepest muscle in the stomach. The hip flexors work to lift and hold your legs slightly off the floor during the exercise. The transverse abdominis aids in maintaining your stability, posture and balance. It also pulls the abdominal wall inward, and with the help of the rectus abdominis and the obliques, it holds the abdomen flat. Because the transverse abdominis is involved in so many daily movements, it's beneficial to strengthen the muscle through exercise.
Other muscles involved in scissor kicks include the rectus abdominis and the obliques. The rectus abdominis muscle runs vertical in front of the torso and is more superficial than the transverse abdominis. The obliques are two different muscles known as the internal obliques and external obliques, and they are involved in rotation and lateral bending of the spine as well as movement and stability.
Performing scissor kicks with improper technique can put strain on your lower back. Begin by lying on a mat face-up. Before raising your legs off the floor, engage your core by imagining you are pulling your belly button in toward your spine and pressing your lower back flat on the mat. Keep your back pressed onto the mat throughout the exercise.
If you are a beginner, raise your legs to a 45-degree angle and keep your knees bent. The lower and straighter your legs are to the ground, the more challenging the exercise will be. Spread your legs out to the side, and then cross one leg over the other in the middle before bringing them back out to the starting position for one repetition. Repeat the movement.
Tips and Considerations
Other exercises that target your transverse abdominis include reverse crunches, seated trunk rotations and planks. It is also important consider muscle balance -- if you are working your abdominals, be sure to strengthen your back muscles as well. As with any strength training program, rest is essential. The American College of Sports Medicine advises that you wait 48 hours between strength-training sessions, in order to give your muscles the time they need to repair themselves and grow.