Rotational Athletes and why you MUST know about the Serape Effect

The Rotational Athlete 

In today’s blog we will be discussing a pattern in the overhead/rotational athlete, called the “Serape Effect”. Gene A. Logan and Wayne C. McKinney introduced the Serape Effect to us in their book, “Kinesiology” a couple centuries ago.  The Serape Effect gets its name from a Mexican garment that is draped loosely over the shoulders and is crossed in front of the body.  The muscles involved in the serape effects are the rhomboids, serratus anterior, external obliques and internal obliques. “The Serape Effect incorporates several major concepts which are vital to the understanding of movement. In ballistic actions such as throwing and kicking, the serape muscles add to the summation of internal forces. They also transfer internal force from a large body segment, the trunk, to relatively smaller body parts, the limbs. For example, the serape effect functions in throwing by summating, adding to, and transferring the internal forces generated in the lower limbs and pelvis to the throwing limb.” (Logan & Mckinney p. 154) The serape effect establishes a connection between opposite hip to opposite shoulder. It also establishes the slingshot effect that occurs as power transfers over from the trunk (core/ hips) to a limb (arm and leg). 

  This concept has also been explained in the book “Anatomy Trains” by Thomas Myers. It is identified as the “Spiral Line” and connected more muscle than the four proposed by Logan and McKinney. These athletes are your soccer player, baseball/softball, swimmers, runners, lacrosse players, and etc. It’s pretty much every sport that uses a rotational movement pattern to create power. Lets take a look at how these muscles are used in a right-handed thrower. “There is definite interaction between the pelvic girdle on the left and the throwing limb on the right by way of concentric contraction of the left internal oblique, right external oblique, and serratus anterior on the right at the initiation of the throw, The pelvic girdle is rotating to the left and rib cage is rotating to the right.” (Logan & McKinney p. 156) 

Repetitive movement of this pattern causes a dysfunction throughout the whole body.  There are many reasons why this dysfunction occurs. Lets continue with the throwing athlete as we highlight some of these reasons. Due to the forward ballistic action produced by the acceleration of the throwing movement, the muscles that are used in unison to decelerate (anti-rotation muscles) the movement become stretched and in the long term weakened.  This causes the body to make compensation for the lack of strength and in turn alters the movement. Pain might also develop as a secondary effect of the weakness. To put this in terms for people to understand better, a right handed pitcher will have very strong muscles in the front of their bodies. The front part of their right shoulder and left hip will be strong and will shorten. While the posterior part of their bodies will get really weak, and they will not be able to decelerate or slow down their arm from moving. This causes many injuries in the shoulder joint. 

The body will only allow you to go as fast as it could stop itself. If the athlete does not take the proper time to strengthen the deceleration muscle of the movement that is constantly being produced, overuse injuries will occur. Perfect example to compare this point is a slingshot.  Lets say that the handle from the slingshot is the trunk and the rubber bands are the muscles that produce the throwing motion. The pouch where the stone or whatever you are throwing is the hand with the ball and your hand, which goes on the handle, are the legs.  A new slingshot will be strong and not much effort will be needed to produce a powerful shot, but a slingshot that has been used for a while will need more of an effort. This is due to the tension placed upon the rubber bands. Constant pull on the rubber band will cause it to lose its contractibility just like constant stretch on the deceleration (anti-rotation) muscles will cause them to become weaker.  If you do not understand that analogy, here is what we are saying. If you have no stability within your trunk, you will overuse your other muscles. This will cause those muscle to overstretch and not work will. So you will lose power and not be able to generate force. 

You are probably wondering how you can prevent this from happening. Well its quite simple; strengthen the muscles that work opposite from the movement.  You must also work the ENTIRE pattern. Isolation exercises in this case do not work well for preventing these injuries. The best exercise we have seen the help with working these spiral lines is the "Serape Squat" invented at FLO Fitness. Check out the video below for instructions on it. Do this exercise every session with your rotational athletes and you will see how much they will improve. You will also need to address other areas but try this exercise out. 

http://www.youtube.com/watch?v=hTe2jVaRHO0