Hamstrung

hamstrung  past participle, past tense of ham·string (Verb)

Verb

1. Cripple (a person or animal) by cutting their hamstrings.
2. Severely restrict the efficiency or effectiveness of.

OK, this post is not about cutting one's hamstrings, and disabling them...but it is about how our hamstrings can disable, or cripple us...specifically, during the golf swing.

How many of you have tight hamstrings?  How many of you don't know if your hamstrings are tight or not? 

How many of you just don't care?  Alrighty then...move along. 

What are the hamstrings anyway? 

The hamstrings are a group of muscles that are part of what is known as the posterior chain.  The posterior chain is comprised of the muscles that are located posteriorly on our body...on our backside.  The hamstring muscles include the Biceps Femoris (long and short heads), the semimembranosus, and the semitendinosus.

The actions of the hamstring muscles include knee flexion, hip extension, hip flexion, rotation of the tibia...both external and internal rotation.  As you can see the hamstring muscle group is responsible for a great deal of lower extremity movement - which means that it sees more than it's share of action, and thus needs to be taken care of.

Yesterday I mentioned that a rounded back posture during the golf address and swing could be due, in part, to tightness in the hamstrings.   I know some of you are thinking "How can tight hamstrings cause my back to round?"  

Let me explain.

The human movement system (HMS) is comprised of a number of subsystems...groups of individual muscles and muscle groups that work together to create movement, and stabilize the body.  The hamstrings, specifically the Biceps Femoris, is part of the Posterior Oblique Subsystem (POS).  Here is a quote from the National Academy of Sports Medicine Corrective Exercise Specialist textbook...

"...the POS transfers forces that are summated from the muscle's transverse plane orientation to propulsion in the sagittal plane.  The POS is also of prime importance for rotational activities such as swinging a golf club or a baseball bat, or throwing a ball."

What does all that mumbo-jumbo mean...and how does it pertain to you and your golf swing?

In short, what it means is that forces are transferred along the muscles that belong to the POS, starting from the ground up.  When you swing your club, you create ground-force by driving your feet into the ground to stabilize your body during movement.  This force is then transmitted upward, through the posterior chain musculature, through the Biceps Femoris, and into the thoracolumbar fascia (TF).  The TF attaches to the various points within the hip complex, as well as to the latissimus dorsi (lats) musculature and deep spinal musculature...as shown in the picture below.

When there is over-activity or tightness in the Biceps Femoris, the muscle pulls downward on the TF (as shown by the blue arrows).  This creates tension across the TF and all the way up into the lats and spinal musculature.  Tension of this sort can actually cause a great deal of low-back pain during both normal and sports related activities.  

Due to the tension in the TF, it becomes increasingly difficult (and uncomfortable) to flex at the hips, as is required during the golf swing.  The body compensates by flexing throughout both the lumbar and thoracic spine...creating the rounded back posture seen below.  You will also see that the golfer below has very little knee flexion (bending) at address.  This too is a result of tight hamstrings, as they cross the knee joint.  Poor ankle flexibility (tightness in the calves) can also play a significant role in decreased knee flexion.

This golfer clearly has tight hamstrings, and is placing a great deal of stress on his back.

Our own hamstrings can cripple us.  Not only on the golf course but in everyday life.  What seems relatively benign can, both acutely and chronically, result in pain and dysfunction throughout the body.

Take care of your hamstrings and they will take care of you!

Check back soon to see just how you can take care of your hamstrings.

Yours in Health and Performance, 

John