Classification
Type | auxiliary |
Mechanics | compound |
Direction | pull |
Equipment | flat bench |
Additional Equipment | - |
Instructions
Preparation
Lie in flat supine position on flat bench. Let legs hang straight off one end of the bench. Extend arms above head and raise head slightly.Execution
Pull legs and arms simultaneously up until legs are positioned about perpendicular above hips. Maybe let hands and legs touch slightly. Raise torso up while lower back remains on bench. Return to starting position with controlled speed and return.Variations / Comments
Jack Knife is quite a complex exercise that requires some training experience along with a certain hip flexibility. The slower Jack Knifes are done the harder they become.![Bodyweight Only Jack Knife | Starting Position Bodyweight Only Jack Knife Starting Position](/data/exercisefiles/32/2932.jpg)
![arrow arrow](/template/images/position_arrow.gif)
![Bodyweight Only Jack Knife | Ending Position Bodyweight Only Jack Knife Ending Position](/data/exercisefiles/33/2933.jpg)
Muscles
Target | Rectus Abdominis | Hip Flexors |
Synergist | - |
Stabilizers | Obliques |
![Bodyweight Only Jack Knife | Muscles Front Bodyweight Only Jack Knife Muscles Front](/data/musclemaps/19/1219.jpg)
Front
![Bodyweight Only Jack Knife | Muscles Rear Bodyweight Only Jack Knife Muscles Rear](/data/musclemaps/20/1220.jpg)
Rear
![High End Visualizations](../../template/images/banner/sa_bodytrainer_tv_banner.png)