Jackknife On Exercise Ball

General And Specifics

• this ab exercise strengthens the core and the hip flexor

Starting Position

• support yourself with stretched arms and bring the shins on the gym ball
• the hands are under the shoulders, the legs are stretched out
• your whole body is in a straight line

Correct Execution

• brace the abs
• bend the legs and guide the thighs forward until they are vertical to the ground
the gym ball moves towards the hips and is arranged under the feet in the final position
• hold the position for a bit
• stretch out your legs then and roll the ball back into the starting position again
• the upper body is stable during this exercise
• repeat this stability ball exercise several times