Perfect Posture: Connect your kinetic chain with external rotators

Anders Hendricks, Aurora Sports Medicine Institute

Anders is a licensed athletic traininer at the Aurora Sports Medicine Institute in Burlington and at Badger High School in Lake Geneva.

Growing up, I’m sure everyone learned the basic body parts through the song about connecting bones.  “The _____ bone’s connected to the ______ bone”, which starts at the head and moves all the way down to the toes.  In actuality, that song isn’t very far off.  Of course, there are many other parts of the human body that connect besides bones, but the basic idea is fairly accurate.

When learning about advanced anatomy and how posture works, people will inevitably discuss the “kinetic chain”, which is an idea about how motion at one body segment or joint affects motion at other joints.  The kinetic chain also describes that a weakness in one area of the body may cause pain in other parts.  An excellent blog by an athletic trainer describing the kinetic chain in detail can be found here.  There are literally hundreds of examples of how deficiencies in one part of the body causes problems in others, this blog entry will focus on how weak external rotators of the hip can cause ankle, knee, hip and low back pain, and how improving the strength of the external rotators causes an increase in stability and decrease in pain.

Initially, it is important to offer some background information.  External rotation at the hip can be shown by moving ones foot in an outward motion – the hips are externally rotated if ones toes are pointing away from each other, or if a person crosses one ankle over the other knee, pictured here, in which the right hip is externally rotated.  Internal rotation is just the opposite.  It is commonly shown when the knees are presented close together (knock knee), or when the toes point in (pictured here).

There are many muscles that help externally rotate the hip; this blog will focus on the two most important: the gluteus maximus (glut max) and piriformis muscle.  The glut max (pictured here) originates over the tailbone and posterior (back) hip and inserts on the IT band and the superior (top) posterior (back) portion of the femur.  The piriformis (pictured here) lies under (deep) to the glut max, reaching from the tailbone to the top of the greater trochanter (the bony prominence at the outside (lateral) portion of the hip).

When walking or running, a person’s body must accommodate for the stresses placed on the body when the foot impacts on the ground.  These stresses, called ground reaction forces, can be equal to three times the body weight when running!  In order to properly dissipate these forces without causing undo stress to joints, the body relies on muscular stability to keep body segments in good posture.  When a person has weak external rotators, the hip may be unable to keep from internally rotating during movement.  This internal rotation at the hip causes a buckling (valgus) force over the knee (pictured here), and other postural problems in the lower body.  I often times see high school student-athletes complaining of hip, knee, ankle and foot pain when poor hip musculature is to blame.  One helpful tip to maintaining perfect lower body posture is by exercising to make the external rotator muscles of the hip stronger.  Below are some suggestions for exercises will aid with this.

When first starting to exercise a new muscle group, it is important to start with the basics.  An excellent introductory exercise for the external rotator muscle group is clamshells.  To properly perform this exercise, a person starts out lying on their side (the side that is up will be the one that is being exercised).  With their back flat and head supported by a pillow or their arm, the person keeps their back straight and bends both knees to 90 degrees with the top hand resting on the top hip (pictured here).  From there, the person lifts their knee as high as they are able.  It is important for this exercise that the core is held tight, and that there is no motion in the persons shoulder, low back or hip area.  An excellent article going into further detail about this exercise can be found here.

Another way to isolate the external hip rotator muscles is the tie a piece of elastic tubing or band into a circle, and place it just above a persons knees (pictured here).  While doing exercises with the band around the knees, the goal is to keep the knees parallel and equal distance apart, which is done so by using the hip external rotators.  Examples of exercises that can be done while utilizing the loop of elastic tubing includes wall squats, leg press, and hamstring bridging (which is described in Perfect Posture #4 – Healthy Hamstrings).  A person can even add the elastic tubing to the clamshell exercise, making it more difficult.

By properly strengthening these muscles, it will allow your lower body to perform activities with better posture, leading to decreased pain and soreness and increased efficiency.

For questions, or to suggest future topics, feel free to send me an email at  Thanks a bunch!


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Don’t give up the sport — give up the pain! Visit the Aurora Sports Medicine Institute at 13 Wisconsin locations, visit our website, follow us on Facebook,  browse our YouTube channel, or call our hotline at 1-800-219-7776. 


About Anders Hendricks

Anders Hendricks is a Licensed Athletic Trainer for the Aurora Sports Medicine Institute in Burlington and at Badger High School in Lake Geneva. Anders studied Kinesiology and Athletic Training at the University of Wisconsin-Eau Claire, and has worked as an athletic trainer at the University of Wisconsin at Parkside. In the summer and fall, he enjoys following the Green Bay Packers and Milwaukee Brewers, and ice hockey and downhill skiing in the winter. Anders started blogging to give people a better understanding of what athletic training is, and how licensed athletic trainers help the patients of Aurora Health Care live well.
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One Response to Perfect Posture: Connect your kinetic chain with external rotators

  1. wartica says:

    I totally agree ;anytime I’m hunched over at work ,I can automatically feel pain and discomfort . Great post and I look forward to sharing more with you:)

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