Hamstring, hip and lower back conditions are most often interrelated, and there's often a domino effect of inflexibility and/or injuries as a result.
So, first things first.  What do tight hamstrings have to do with back pain?  A lot! Your back, especially your lumbar spine (lower back), is designed to be fairly stable. The network of muscles in your core (abdominals and pelvic floor) and surrounding your spine are there to support you in an upright position.We are designed to be on our feet and moving, and that means our hips, where are legs attach to our pelvis/torso, are meant to be flexible and fluid so we can take strides, moving ourselves from one place to another. But more often than not, what we typically are doing is sitting.  And, usually it is for prolonged periods of time.  At work, sitting at a desk; at home, watching TV, etc. And all that sitting on our butt, and not moving, causes our hips (where all of the hamstring muscles connect to the pelvis) to get really, really tight.
OK, great. But how do tight hamstrings make my back hurt?
So, the tightness of your hamstrings causes your pelvis to be pulled down and away from the lumbar spine, which puts the lower back in a position of instability–the exact opposite of what it needs!
But, wait just a minute.  What about the hip flexors?
Good question.  The iliopsoas is a key muscle for great posture and length in the spine and back. Without adequate length in the psoas, one cannot walk tall, and one can experience a hunched back and a lack of movement in the hips and legs.  What many do not realize is that much lower back pain can also be traced back to the muscles of the hip; that is, when the hip flexor muscles are overly tight, they can lead to pain in the lower back.
I hope I haven't caused any confusion up to this point. I don't want to simplify the complexities of these parts of our body with these brief descriptions alone. It is only intended to provide a glimpse of the possibilities of, for whatever the reason, imbalances in our body can occur.  This then can result in discomfort, limited range of motion and inflexibility. 
Tackling the unique mystery as to why one has back pain or is suffering from tightness in the hips and hamstrings, well, that should explored and/or assessed by a medical professional. 
My point is that hamstring, hip and lower back conditions are most often interrelated.  In designing his week's Yin practice I wanted to focus on targeting our lower back, then our hips, move into our hip flexors and then target our hamstrings - in that order.  Which means we'll be moving from Happy Baby into Deer, then Swan, Dragon and finally to Caterpillar.  It is my hope that we'll all be feeling a little looser and open after our class this week. 

I like how Paul Grilley, auther of "yinYoga: Principles and Practice" expresses the importance of targeting connective tissue as well as stressing the joints, in the passive practice of Yin yoga.  And, despite Yin yoga's ability to condition one to sit longer, and more comfortably - this passive practice provides so many more benefits to us physically as well as mentally and emotionally.  The article I am referring to appeared in a past Yoga Journal article, and amongst other details, it outlines the principles and benefits of this quiet practice.  And why cultivating stillness can be so beneficial for us on so many levels.  Here is the link to the article, please take five and read on...
http://www.yogajournal.com/practice/580

Photo credit - obtained from above Yoga Journal

I wanted to take a moment to share a little Yin pose as I find this a nice way to get a little reclining twist that gives the lower back, quadricep and IT band some attention.  'Cat Pulling It's Tail' can either be a nice counterpose from any deep forward fold pose (such as 'Caterpillar', 'Snail' or 'Dangling' pose - all Yin poses).  However, this is also a nice pose in of itself.  Not only does this provide a nice compression to the lower back, but it also opens the quadriceps and upper thigh, and it can also be a nice stretch for the IT band as well.  Plus, the feeling of a twist may indicate that the rib cage is getting some attention as well (if you have lower back issues - go gently).  A more challenging option is to recline and look over the shoulder to the bottom foot.  This becomes a reclining twist and a backbend.  And, try pulling the foot away from the buttock (one consideration is that you may not be able to pull the foot away at all).  A lot is going on in this pose so this can be yang-like in nature; in this case you may shorten the time -or- release the pressure after one minute.  
But, remember that it's the pose that should adapt to the body, not visa versa.  I recommend giving it a try. 

So, my post last week referenced an article regarding connective tissue.  Well, here I am again, providing a more specific article on "What is Fascia?" which I obtained from Facebook - Anatomy in Motion.  If you are an anatomy junkie, and if you are a Facebook user, then you may well want to 'Like' them.  Here is the one article that I found on their page which gives a brief explanation on...

What is Fascia?
Fascia is tough connective tissue that creates a 3-dimensional
web extending without interruption from head to toe. Fascia surrounds and infuses every muscle, bone, nerve, blood vessel, and organ, all the way down to the cellular level.
The fascial system affects every system and function in your body- musculoskeletal, neurological, metabolic, etc. The white, glistening fibers you see when you pull a piece of meat apart or when you pull chicken skin away is fascia.
What is Fascia made of ?
Fascia consists of a complex which has three parts:
1. Elastin fibers - This is the elastic and stretchable part of the complex.
2. Collagen fibers - These fibers are extremely tough and give support to the structure. 
3. Ground substance/matrix: A gelatinous like substance that transports metabolic material throughout the body
What does fascia do? 
The fascial system generally supports, stabilizes, and cushions. Fascia creates separation between vessels, organs, bones, and muscles. It creates space through which delicate nerves, blood vessels, and fluids can pass.
What are Fascial Restrictions?
In a healthy state, the collagen fibers wrap around the elastic fibers in a relaxed, wavy configuration. Trauma, repetitive motion,
inflammation, or poor posture can cause the fascia to become solidified and shortened. These thickened areas are referred to as a fascial restriction. Fascial restrictions have the capacity of creating up to 2,000 pounds of pressure per square inch in a restricted area. That crushing pressure can compromise any physiological system in the body resulting in pain and dysfunction. 
The fascia throughout the body is all interconnected like the yarn in a sweater or a complex spider web. A restriction in one area of the body creates tension throughout this web pulling on other distant structures. This explains why some people may have pain that appears unrelated to their original injury. Furthermore, myofascial restrictions do not show up on common standardized tests such as x-rays, MRI, CAT scans, etc.
Fascial restrictions can pull the body out of its normal alignment, compressing joint surfaces and bulging disks, resulting in pain, loss of motion, and weakness.  
Info collected from Spine - Health, Mayo Clinic, NIH &
Medterms. Photo credit: art by Dan Beckemeyer