There is also a special null type, the type of the expression null, which has no name. Because the null type has no name, it is impossible to declare a variable of the null type or to cast to the null type.
Transcript of Muscles Used for Jumping Jacks! Muscles Used for Jumping Jacks! FONTS. Muscles of the Abdomen- Anterior View. Rectus Abdominus. : Helps stabilize the movement to create pressure through a jumping jack. Muscles of the Lower Extremity. Anterior View (leg)-.
To burn more jumping jacks calories, it is important to do this exercise in a proper way. 1  Here are the steps to achieve a great result: 2  Stand upright with both your feet together and arm extended by your sides. 3  Bend your knees a bit and push your body using the balls of your feet.