Yoga Therapeutics - Hamstrings
by Michael Stein

Welcome to Yoga Therapeutics. In these articles we will view Hatha Yoga as a form of physical therapy by gaining an understanding of the relationship between the asanas (postures) and their related anatomy. By deepening this understanding we may use our yoga practice to either heal ourselves of existing injuries or, more importantly, keep our bodies supple, strong, and healthy throughout a lifetime. We will start with the muscle group that all practitioners, whether beginner or advanced, are intimately familiar with – the hamstrings.

While every Anatomy workshop I teach is slightly different, I find that one question will inevitably come up: “Why do all forms of Hatha Yoga emphasize hamstring flexibility so much?” This is a good question. One that often springs from the common frustration that most people feel when they first begin practicing yoga or when an instructor corrects their alignment in forward bends. It can be very humbling to find that we can barely touch our ankles with straight legs when we are used to reaching for our feet. Furthermore, while it may be obvious that tight hamstrings limit our range of motion in all standing and seated forward bends (such as Uttanasana or Paschimottanasana) it may be surprising to learn how much they may limit us in standing balances, prone postures, and any form of therapy for our lumbar (lower back) region. Before delving into specific asanas lets take a look at the anatomy of the hamstring muscles.

These three long muscles all originate on the sit-bones (aka Ischial Tuberosity – the lowest point of our hip bowl). The Semitendinosus and the Semimembranosus run down the back of the thigh and insert on the inside (medial side) of the knee at the tibia (shin) bone, while the Biceps femoris inserts on the outside (later side) of the knee at the fibula bone. Since all three hamstring muscles cross the hip and knee joint their main function as a group is to perform one basic action: bending the knee by bring our heel towards our buttocks (known as flexion of the knee joint). Each time we do this action the hamstrings shorten slightly, which is perfectly natural and healthy. Problems tend to occur, however, when this action becomes repetitive over the course of many years. Sports such as running or biking may cause the hamstrings to become hypertonic (extreme muscular tension) when there is not enough stretching to counter balance the constant shortening. Runners also suffer from this problem due to the pounding that is created each time they land on one foot.

In and of itself short hamstrings will affect your posture but may not affect your life to any great degree until you encounter lower back problems. Lower back pain is the most common muscular ailment in America. Unfortunately, it is a condition that many people are forced to live with for years with no relief in sight and, in general, it could be avoided altogether with a quick and simple daily routine of hamstring stretches. We now come to two obvious questions: “At such a distance, why do these muscles, located on the posterior thigh, affect our lower backs at all? And “How can we use yoga postures to prevent or heal such an injury?” The answer lies with the hips.

Even though we think of the hamstrings as being on the thigh they are always tugging on the lower hips at the sitting bones. Therefore, when they become tight (or short) the hamstrings can actually pull our sit-bones down towards our knees, causing what’s known as a posterior pelvic tilt. Since our hips connect to the sacrum, spine, and lower back region, walking around for years with an exaggerated posterior pelvic tilt causes us to lose the natural curve that we are born with in our lower back, known as the lumbar lordosis (the inward, C-shaped arch of the lower back). When this happens our lower back flattens slightly and the lower back muscles of that area become slack, rather than strong as they are meant to be for good postural support. Moreover, the ligaments between our vertebrae are prone to being overstretched, possibly causing a bulging or herniated disc. Depending on your lifestyle this can still be overlooked until the day when we inevitably lift a heavy object and feel a shooting pain or spasm in our lower backs. The blame then for the injury, be it muscular or joint pain, will thereafter be spoken of as “That stupid, unconscious, split-second of heavy lifting”, but what really caused the injury was years of hamstring neglect.

If you already have chronic lower back pain then stretching the hamstrings in the wrong way can easily make it worse. Yoga teachers are constantly reminding students to hinge forward from their hip joint, not from their waist. This is humbling, challenging, and often misunderstood by even the most consistent practitioners. In order to hinge from the hips while forward bending visualize taking your chest, instead of your forehead, towards your knees; imagine kissing your big toes, instead of rounding your upper back to reach for them at all costs. When we bend from our waist, as most of us do all too often when we do yard work or lift heavy objects, we flex our vertebral column, causing the lower back muscles to become stretched, and we generally bring our shoulders towards our ears, causing what’s known as hyper-kyphosis (rounded shoulders), both of which create postural misalignment, one that is hunched rather than upright.

If you are new to yoga, or stretching in general, the safest way to stretch your hamstrings is by lying flat on your back. By keeping your lower back area close to a flat floor you can be fairly certain that you are not overly rounding the lumbar region while working to bring your chest towards your extended knee. From this reclined position start by bending your left knee, bringing the sole of your left foot flat to the floor, then hugging your right knee to your chest. Using a towel or a belt, hook around the sole of your right foot and straighten your right leg towards the ceiling. The belt or towel acts as an extender for your arms, allowing your leg to straighten no matter how tight your hamstrings have become. Find steady, rhythmic breathing and then lift your head up while gently bending your elbows (Fig. #1). It is important not to have your right leg rigid or hyper-extended and also be mindful of not bringing your shoulders towards your ears, thereby tightening your upper back muscles. When you lower your head continue to stretch with your neck completely relaxed. After about ten breaths repeat the posture on the opposite side. Once you become more flexible you can do the same sequence with the bottom leg straight along the floor, creating a greater pull on the hamstrings.

Another good hamstring stretch for all levels is the beginners version of Parsvottanasana (the intense stretch to the side). Start standing with your legs in a small triangle position, your feet should be wider apart than your hips. Rotate your left toes in towards your right foot at about 45 degrees and rotate your right toes out to the right at 90 degrees; your heels should be in a straight line with each other. With your hands on your waist turn to face your right thigh using your thumbs at the lower back to remind you to square your hips as much as possible. On a slow exhale, hinge from the hips, allowing your navel to come towards the middle of your right thigh and your chest towards your right knee cap (don’t worry if you don’t get anywhere near these destinations, they are just focal points for alignment). Keep your spine long throughout and if your fingertips can’t reach the floor with a straight spine then use blocks on both sides of your right foot to raise the floor up to your hands. If you are more flexible take your fingertips and eventually your palms to the floor (Fig.#2). Remind yourself to lengthen, or arch, your spine on each inhale and dive forward, chest towards knee, on each exhale. By gaining an understanding of hip-flexion and proper alignment in this standing forward bend you will be able to use the same good alignment in all of your seated forward bends.

When it comes to hamstring flexibility most people think of Hanumanasa (the full split) as some sort of goal that may be reached by only a select few. I would encourage all practitioners to think of every asana as approachable and therapeutic, instead of a text book shape that we must produce in order to feel successful. When approaching Hanumanasana be sure that you are already warmed up and you are not practicing in a cold environment. By using blocks under your hands and a large pillow under your pelvis (Fig. #3) you can safely come into this posture regularly and breath until you feel the limits of your unique stretch. With a daily practice (that must also include hip openers) your hamstrings will remember the suppleness that they once felt as children and all movements - from running to kicking to jumping - will take on a new lightness that will add much more life to your years.