“. . . according to the Yoga Sutra (3.1), the term [Bandha] refers to the ‘binding’ of consciousness to a particular object or locus (desha), which is the very essence of concentration.”
Georg Feuerstein



Wednesday, January 26, 2011

How Tight Hamstrings Affect Your Lumbar Spine

Hello Friends,

Here's a quick 2016 update from the science literature on your hamstrings...

Biomechanically speaking, tight hamstrings can affect the position of your pelvis, especially in forward bends. This can, in turn, affect your lumbar spine because tight hamstrings produce a pull on the ischial tuberosities and tilt your pelvis back (as shown below in figure 2).

Adjacent joints move in what is known as a “coupled” fashion. When the pelvis tilts back, the lumbar vertebrae flex forward. This means that if the hamstrings are tight and we bend forward in Uttanasana, more of the flexion comes from the lumbar spine. Conversely, when the hamstrings are flexible, the pelvis can tilt forward, allowing the forward bend to come from the hip joint, rather than the lumbar spine.

This interaction is known as spino-pelvic rhythm and is how the pelvis and lumbar spine move in relation to each other. Ideally, we want to have have a forward bend come predominantly from pelvic movement (pelvic dominance) rather than from the lumbar (lumbar dominance).

To this end, I wanted to share a couple of articles from the recent science literature relating to how tight hamstrings affect your pelvis and lumbar spine. The first one discusses spino-pelvic rhythm in relation to the hamstrings. These researchers investigated forward bends (essentially Uttanasana) in subjects with tight hamstrings vs flexible hams.

What they found was...

"The lumbo-pelvic-rhythm comprises 2 patterns—lumbar dominant and pelvis dominant. In flexible subjects, pelvis movement was dominant. In conclusion, improving tight hamstrings may reduce lumbar loading thereby reducing low back pain."

And in a subsequent article they concluded that:

"Dynamic stretching could change the spino-pelvic to a pelvis-dominant motion, indicating that flexible hamstrings are important for preventing low back pain."

Yet another article reported that:

Hamstring stretching exercises performed in the working place are effective for increasing hamstring muscle extensibility. This increase generates a more aligned thoracic curve and more anterior pelvic inclination when maximal trunk flexion is performed."

(click on the references below to read the articles)



Figure 1 shows what happens with flexible hamstrings...


hamstrings releasing in uttanasana
Figure 1: This illustrates how stretching the hamstrings releases the pull on the ischial tuberosities,
permitting the pelvis to tilt forward into anteversion. This is known as femoral pelvic rhythm.

Figure 2 illustrates what happens when your hamstrings are short or tight...



tight hamstrings in uttanasana
Figure 2: Uttanasana: tight hamstring drawing pelvis into retroversion and
coupled movement of lumbar spine into flexion. This is lumbar pelvic rhythm.

As the research demonstrates, stretching your hamstrings can help take the strain off of the ligaments and disks of the lumbar spine. Click here to read more on this subject. Click here to read about the role of the thoracolumbar fascia and the core muscles in protecting the lumbar. Click here for some cool information on gaining flexibility in your hamstrings as well as the myofascial connections between your hammies and your feet. (This shows how everything is connected...)


Figure 3 illustrates the intervertebral discs bulging during lumbar flexion.


bulging lumbar intervertebral discs
Figure 3: Lumbar spine in hyperflexion illustrating bulging discs.



Here's a quick review of the anatomy of your hamstrings...

The hamstrings comprise three separate muscles—the semimembranosus, semitendinosis, and biceps femoris. The biceps has a long and short head. The semimembranosus, semitendinosis, and long head of the biceps originate from the ischial tuberosities (sitting bones). The short head of the biceps originates from the back of the femur (thigh bone). The semimembranosus and semitendinosus insert on the inside of the tibia (lower leg). The two heads of the biceps join into one tendon that inserts onto the head of the fibula at the outside of the knee. The main action of the hamstrings is to flex the knee. Secondary actions include extending the hip and rotating the knee.

Thanks for stopping by. Click here to browse through our books for more key information on anatomy, biomechanics and physiology related to your yoga practice! See you later this week for a QuickQuiz on your hamstrings...

Namasté,

Ray Long, MD

1Hasebe K, Sairyo K, Hada Y, Dezawa A, Okubo Y, Kaneoka K, Nakamura Y. “Spino-pelvic-rhythm with forward trunk bending in normal subjects without low back pain.” Eur J Orthop Surg Traumatol. 2014 Jul;24 Suppl 1:S193-9.

2) Hasebe K1,Okubo Y, Kaneoka K, Takada K, Suzuki D, Sairyo K. "The effect of dynamic stretching on hamstrings flexibility with respectto the spino-pelvic rhythm." J Med Invest. 2016;63(1-2):85-90.

3) Muyor JM1, López-Miñarro PA, Casimiro AJ. “Effect of stretching program in anindustrial workplace on hamstring flexibility and sagittal spinal posture ofadult women workers: a randomized controlled trial.” J Back Musculoskelet Rehabil. 2012;25(3):161-9.

12 comments:

  1. I am really enjoying your blog! I made my way to it one way or another through internet surfing and am so pleased! As a yoga instructor this is all very helpful and I have passed it on to others!

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  2. You all at Bandha yoga are a blessing-to my lax abdominals and tight hamstrings-and to improved practice for all. Thank you for your total dedication.
    sophie otis

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  3. Thanks Sophie! much appreciated--Ray

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  4. I'm so glad I found this blog - a great bite-sized way to learn more about anatomy. I have some of your books, but this format is super helpful.

    As a yoga teacher, I often see students in that second uttanasana position with hyper flexion in the lumbar spine. Aside from helping them work on hamstring flexibility over time, what do you suggest in the moment to help them take the flexion out of the lumbar spine? Bent knees?

    Thank you!

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  5. Hi Julia,

    Take a look at these two links on our Web site. I recommend that the students partially release the stretch of the hamstrings (either by coming up part way from the pose or by slightly bending the knees). Hold this position for 3-4 breaths and then engage the quads to straighten the knees (and produce reciprocal inhibition of the hams).

    When you stretch any muscle, the reflex arc associated with the muscle spindle is stimulated and you get a reflex contraction of the stretching muscle. This tightens it. If you come part way out of the stretch for a few breaths, this "acclimates" the muscle spindle and decreases firing. Then the muscle releases more. At this point the student can generally go deeper.

    http://www.bandhayoga.com/keys_fire.html

    http://www.bandhayoga.com/keys_hams.html

    Thanks for your comment and question. Try this on yourself first and see the effect. As the students’ conditioning improves, you can add a gentle facilitated stretch (see the blog post on this).
    Stay in touch and let me know how it goes.

    Best,

    Ray

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  6. I also wanted to say Thanks! I read these posts with interest. The illustrations are outstanding, and together with the text really make these useful points very clear. They are a help to me, and offer much to pass on to my students!

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  7. These pictures also illustrate how the attachment points could possibly get aggravated with the slight bend in the knees and less so with straight legs, as in my care.

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    Replies
    1. Yes some time I have tge sane feeling myself.. (Pierluigi)

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  8. My perspective on this: If the focus of a forward bend shifts from the hamstring to an elongation of the psoas, (hence the work of the lumbar region of the spine), then we automatically work with pelvis and the hamstring stretch become secondary. This prevents tears of the hamstring attachment to the ischial tuberosity along with encouraging a healthy lengthening of the hamstring muscles instead overextending the attachments.

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  9. What do you think about stretching the calf and the plantar fascia with a strap on the ball of one foot and the leg straight on the mat, extending thru the heel as you pull back on the foot? Thanks

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