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)-.
Everything from the calves to hamstrings to tensor muscles in the thighs are used to jump and land during each rope revolution. The core muscles in the abs are also engaged, especially during jumping variations that require extra balance, such as a one-legged jump.