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)-.
Variations [edit]. More intensive versions of this jump include bending down (over) and touching the floor in between each jump. Power Jacks. Power Jacks are similar to jumping jacks, except a person squats lower and jumps as high as possible during each repetition.A similar jump exercise is called half-jacks, which were created to prevent rotator cuff injuries, which have been linked to the repetitive movements of the exercise.ore intensive versions of this jump include bending down (over) and touching the floor in between each jump. Power Jacks. Power Jacks are similar to jumping jacks, except a person squats lower and jumps as high as possible during each repetition.