Exercise description of the bench jackknife.  Learn about the bench jackknife with video and pictures.  Also learn how the bench jackknife can increase your sports performance.

Primary muscles worked:  Lower Abdominals

Synergist Muscles:  All other abdominal muscles

Mechanics:  Isolation

Equipment:  Flat Bench

How to perform the exercise:  To perform the bench jackknife, the athlete should lay with their back flat on a bench. The athlete should reach behind with their arms overhead and grab hold of the bench. The athlete should also have their feet together and straight in the air. Next, the athlete will lift their butt off of the bench trying to bring their heels up toward the ceiling. The athlete should make sure perform the movement in a slow and controlled manner.  Once the athlete has extended up, he/she should hold at the top position for a brief moment and then lower their butt back toward the bench.

Spotting the exercise:  The spotter for this exercise is responsible for making sure the athlete is not utilizing momentum to perform the lift.

Sport specific application:   The bench jackknife is an excellent exercise for developing the lower abdominals of the core. The lower abdominals are often under trained in athlete's which leads to imbalances causing other muscles to overcompensate. Since the lower abdominals are so close in proximity to the legs, their development is highly critical in sports that require power transference from legs to the upper body. Throwing motions, rowing, and punching are just a few examples of the many examples of motions that require strong lower abdominals.