Prone Jack Knife

The Prone Jack Knife is not only an exercise I see performed more often poorly, but it is also an excellent assessment tool. The general idea is you roll forward over the ball until the ball is under the foot. With the arms under the shoulders, you pull the knees under the hips then reverse and push out. What can possible go wrong?

This Prone JackKnife requires a lot of torso strength along with core function, especially the Inner Unit. The dowel is held in place and should remain in contact with the body between the glutes, between the shoulder blades and with the back of the head. The knuckles of the hand at the lumbar spine should remain in contact with the spine. What do we look for?

• Can she maintain all points of contact with the dowel?

• Does she round the thoracic spine for leverage?

• Does the lumbar spine and hips drop?

• Do the pelvis or ribcage twist?

• Does she fall of the ball?

• Is there fluidity and control of movement, slower is better to eliminate momentum and compensation?

• Does she pull from the hips or with the toes, do muscles cramp, if so which ones?

• Does she attempt to shift the ball higher up the ankle to the shins ?

There are many compensations and each one tells a story specific to that individual and their unique situation. Keep in mind with movement pattern testing such as this, if you compensate and then train the body with compensations, those compensations will be ingrained and become the normal pattern of movement. Over time this will place undue stress on the body, joints and tissue putting you at risk of injury and decrease performance capabilities.