Rotational Stability of the Trunk

Rotational Stability of the Trunk

 

When training your trunk (or core) for stability, resisting rotational forces is one complex and important aspect.  Many of the single arm activities that we do, such as the one arm kettlebell deadlift, apply a weight to one side of our body.  This asymmetrical load applies a force on our trunk, which causes it to rotate to one side (our body gives in to the weight).  To stabilize our trunk, we must fight this rotation, and remain "squared off." 

In this picture, the kettlebell in the right hand creates a trunk rotation to the left.  He must stabilize in order to keep his hips and shoulders squared off with a target in front of him

 

There are many beneficial trunk stabilization exercises.  Some are basic, while others are more complex.  Unfortunately, I have seen people in the gym performing most of them with poor technique.  Many people are in a hurry to progress themselves to the more complicated techniques before they really should.  This post will discuss some of the more popular basic trunk stability exercises, proper technique and common errors that I see each day.  It is your job as a trainer to assess your client's abilities in order to progress them properly and avoid injury. 

 

First is the Low Plank and the High Plank.  These are not focused on rotational stability but are more introductory.

Low Plank: Correct - Goal is high reps, holding each one for 5-7sec

High Plank: Correct

 

Low Plank - Incorrect:  This is not acceptable, as you can notice the hyperextension in my lower back and the protruding scapulae.  I am not maintaining stability

  Once you perfect the low and high plank, you may progress to the rotational stability exercise called the High Plank Elbow or Shoulder Tap. 

Wide Base Elbow Tap Start Position

Wide Base Elbow Tap Finish Position: Notice my hips remain "squared off" with the ground

Incorrect Wide Base Elbow Tap: I lost my rotational stability and begin turning my trunk

Progress the above rotational stabilization exercise by modifying the base of support:

Narrow Base Elbow Tap: Start Position and more aggressive due to modified base of support

 

Correct Narrow Base Elbow Tap



Incorrect Narrow Base Elbow Tap: Again notice my rising left hip - If your client is compensating like this even following your verbal and manual corrective cues, they are not ready for this yet

These are just a few of the progressions you can perform when training trunk stability.  Stay tuned for the next post which will discuss other beneficial techniques

 

 

Drive Through Your Hips

Drive Through Your Hips

 

Throwing a ball, swinging a club or a tennis racket and even punching an opponent revolve around rotational force of the hips as well as forces produced through the ground, rather than solely upper extremity strength.  The order of recruitment of power, particularly with heavy hitters is as follows: the swing is led first by the hips, then the trunk, arms, hands and finally the bat.  The more rotational velocity you can produce with your hips, the greater the force transmitted to the ball.  To improve this hip velocity and ground force, you should practice the movement pattern as well as practice the actual task (specificity of training).  If we learn how to create more force through the ground, this increased force will transmit through our bodies and into our target.  Check out the hip position and trailing foot in these pictures:

 

   

 

 

 

 

 

 

 

 

 

If we practice a technique that focuses on hip rotational velocity and explosiveness, we will throw further/faster, hit harder, punch with more force, etc...Here are some simple exercises that will help "groove" the hip rotation motor pattern:  Notice the trailing leg, how the foot pivots, the hip extends, and the 'snap' of the hip rotation/extension.  This creates the force that transmits through the trunk, into the upper extremities, directed toward the goal.  If you do not pivot on your trailing foot, you risk injuring your knee.

 

 

Here, I use a Persian Mil to help train the pivot, hip rotation, and trunk stability, as I thrust the Mil forward. This works the above discussed movement pattern as well as grip strength and shoulder stability.  To challenge the grip even more, I perform this technique using Neurogrips

 

 

 

 Now, I perform the same activity using a longer lever which makes control and stability even more difficult.  This further develops rotational hip velocity, trunk control and coordination of my lower extremities.

 

 

 You can try this out with a wooden dowel to smooth out the movement pattern, and progress to a weighted bar.