If there’s one thing people associate with yoga, it’s flexible hamstrings. After all, how many of your friends refuse to attend yoga class, protesting that they can’t even touch their toes?
Many of us struggle with our hamstrings—stretch after stretch, those irksome posterior thigh muscles spring back as tense as ever. Even those with flexible hamstrings regularly complain of hamstring discomfort. And while there are plenty of hamstring stretches in yoga (forward folds, downward dog) stretching the hamstrings often fails to address the problem. So what will?
We love to simplify and separate, to see each body part in isolation. The reality, however, is not so clear-cut. Every muscle, through its surrounding fascial net, connects to the muscles beside it, below it, above it, and beneath it. Each exists as part of a complex whole, influencing and influenced by all of the structures around it as well as by those that work in opposition. So if you’ve been stretching your hamstrings to no avail, maybe it’s time to take a look at the bigger picture.
Hamstring Anatomy and Function
Let’s start by examining the anatomy in a little more detail. Three hamstrings run down the back of each thigh: semimembranosus, semitendinosus, and biceps femoris (whose name reflects its two heads).
The semimembranosus, semitendinosus, and the long head of the biceps femoris originate on the ischial tuberosities, or sit bones, which are bony knobs at the base of each side of the pelvis, and the short head of the biceps femoris originates at the thighbone. The hamstrings then run down the back of the femur (thighbone), cross the knee joint, and insert on the lower leg bones.
If you palpate the back of one knee you’ll feel three stringy tendons. Side by side at the inner knee are the two tendons of the semimembranosus and semitendinosus (which attach to the larger lower leg bone, the tibia), and at the outer knee is the single tendon of biceps femoris (which attaches to the smaller bone, the fibula).
It’s not necessary to memorize the anatomy. But visualizing the path of these muscles helps us to better understand their function. When the hamstrings contract, they create two primary movements:
1. Hip extension
Moving the femur behind the pelvis, as we do in backbends or in a lunge. In hip extension, the hamstrings (except for the short head of the biceps femoris) assist the gluteus maximus on the back of the pelvis. Their antagonists, the muscles commonly called the hip flexors, include the iliopsoas and rectus femoris (the only quadricep muscle to cross the hip joint).
2. Knee flexion
Bending the knee to bring the tibia and fibula closer to the sit bones. In knee flexion the hamstrings are assisted by the gastrocnemius, a large superficial muscle on the back of the calf, along with some other synergists. Their antagonists in this movement are the quadriceps on the front of the thighs—the rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis.
Now that you’re up to speed on the anatomy, visualize how bending the knee and extending the hip will shorten the hamstrings and how the opposite actions—flexing the hip and extending the knee—will lengthen the hamstrings. In the images above, notice also how the hamstrings connect the pelvis to the lower leg; they not only play a key role in the function of both hip and knee joints but also influence the position of the pelvis (which in turn, impacts the lower back).
As with any other muscles, the hamstrings function best when balanced between stability and mobility, when they are able to perform their roles from varied positions and under varied loads and then rest. Unfortunately for many of us, our lifestyle, postural habits, and movement patterns make it unlikely that we will balance hamstring stability and mobility without a little help.
A major challenge to hamstring health is the amount of time we spend sitting on them. This habit, relatively new in terms of human evolution, chronically shortens the hamstrings, reduces their strength, and limits circulation. Even practicing yoga isn’t necessarily a help, as most yoga practices put more emphasis on hamstring flexibility than on strength.
Any hamstring imbalance has implications broader than just localized tension in the back of the thighs. Overly short or tight hamstrings can pull the top of the pelvis backward, creating a posterior pelvic tilt; overly long or weak hamstrings can do the opposite, allowing the top of the pelvis to tip forward into an anterior pelvic tilt. Nothing occurs in isolation, so the altered position of the pelvis then changes the position of the lumbar spine and the length of the hip flexors. Anterior pelvic tilt deepens the natural lumbar curve, places additional load on the sacroiliac joints, and shortens the hip flexors. Posterior tilt flattens the lumbar curve (placing additional load on the discs between the lumbar vertebrae), and lengthens the hip flexors. Either type of pelvic tilt, if habitual, can have an impact on the lumbar spine, sacroiliac joints, and knees.
So what can we do to help the hamstrings achieve elasticity and resilience and to be able to meet the demands we place on them without strain?
1. Stretch with a neutral spine.
Yoga practices often include a number of standing and seated forward folds, but if our hamstrings are tight enough to lock us into posterior pelvic tilt, we tend to round the lower back and feel more of the stretch in the back muscles instead. There’s nothing wrong with stretching back muscles like the erector spinae, but keeping a neutral spine can help us hone in on our hamstrings. In my opinion, the most effective way to isolate a hamstring stretch is supine hand to big toe pose, or supta padangusthasana, in which the floor facilitates a relatively neutral position for the spine, allowing us to more effectively target the hamstrings.
Give it a try
Lie on your back with your knees bent and feet on the floor, with a belt, strap, or towel within reach. Draw your bent right knee into your chest, holding the knee or shin with your hands for a breath or two to release tension in your gluteus maximus.
Then hook the strap over the ball of your right foot and extend your heel toward the ceiling. You’re looking for a gentle stretch in the belly of the hamstrings (the mid back of the thigh), rather than at the sit bones or behind the knee; you may need to retain some bend in your right knee or reduce the flexion in your right foot to achieve that. If you already feel the stretch, keep your left knee bent and left foot on the floor.
If you don’t yet feel a stretch, lengthen your left leg along the floor, while trying not to arch your back or hike your right hip toward your right shoulder.
Looping a second strap around your right thigh and left foot can help you keep the pelvis neutral.
Once you’ve found a gentle hamstring stretch, stay for at least three relaxed breaths, with chest and shoulders soft, before engaging the quadriceps of your right thigh. When we contract the muscles on one side of a joint we inhibit their antagonists on the other side of the joint from contracting, so in this pose, engaging the quads creates a deeper hamstring stretch. Stay in the deeper stretch for another three to four breaths before releasing your right leg and switching sides. Repeat the stretch every day or two. You may find it especially helpful when your hamstrings are warm after exercise.
2. Vary your stretching position.
You probably will have noticed that different positions change the sensation in your hamstrings. Poses like wide-legged forward fold (prasarita padottanasana) and wide-angle seated fold (upavista konasana) favor stretching the medial hamstrings, semimembranosus and semitendinosus. Positions with the legs together—like standing forward bend(uttanasana) and intense western stretch (paschimottanasana)—emphasize the stretch on the lateral hamstring, the biceps femoris. Many students also find it beneficial to bend their knees or point their toes during hamstring stretches. So rather than just finding a stretch and moving as deeply as possible into your range of motion, varying your position may help release hamstring tension, boost circulation, and encourage lubrication between and around the hamstrings.
Give it a try
Come into supta padangusthasana, using a strap or belt to hook your right foot, once again focusing the stretch on the belly of your hamstrings. This time, stop when you feel a gentle stretch. Keep a little slack in the hamstrings so you can play with varied leg and foot positions. Then bend and straighten your right leg, flex and point your foot, or glide your right leg side to side as if sweeping the ceiling with your foot. Take four or five relaxed breaths, moving smoothly and exploring sensation in the hamstrings, before releasing your right leg and switching sides.
Use this gentle stretch every day or two at the beginning of the day (or before your yoga practice) to warm and mobilize the hamstrings, release hamstring tension, boost circulation, and encourage free movement between and around the hamstrings. You can also use it to loosen up your hamstrings at the end of a long day.
3. Relax with realistic expectations.
If you’re a fan of the “advanced” yoga poses you see on social media, you may be surprised to learn that normal range of motion for hip flexion with a straight leg is around 90 degrees (more or less a right angle between thighs and pelvis). Many yoga poses require more flexibility than this, so yoga class is not necessarily the best place to gauge whether or not you need to improve the range of motion of your hamstrings. If your lifted leg stacks directly above your hips in supta padangusthasana, for example, you may not actually need to increase your flexibility. But if, despite a healthy range of motion, your hamstrings feel stiff or tight, you may then benefit from releasing hamstring tension—relaxing them rather than stretching them.
Flowing stretches like those suggested above can help, but another key determinant of muscle tension is the nervous system. The sympathetic nervous system has many roles, one of which is to increase muscle tone, preparing us for “fight or flight.” On the other side of the equation, the parasympathetic nervous system, responsible for what is often called the “relaxation response,” releases muscle tension. So take the time to find a stretch gentle and soothing enough to relax into. Allowing the hamstrings to relax, to almost drape off the backs of the thighbones, may just release stubborn hamstring tension better than a deep stretch can.
Give it a try
Set up in supta padangusthasana once more, this time lying down through a doorway or against the corner of a wall (or pillar, as pictured below) so that your lower leg is able to relax onto the floor and your lifted leg can lean onto the wall. Get comfortable enough to stay for a few minutes—which may mean creating space between your buttocks and the wall, bending your lifted-leg knee, or placing a cushion under your head.
Once you’re comfortable, become more aware of your breath. The breath is one of the few automatic processes that we can also deliberately control, so it plays a unique role in bridging the conscious and unconscious minds. Slow and easy breathing with a relaxed belly, perhaps lingering for an extra moment in the exhalation, offers an easy shortcut to the relaxation response. Once you’ve settled into deep, relaxed breathing, see how it feels to close your eyes and direct your focus to the subtlety of inner sensation, rather than to the outer shape you make.
Stay for two to three minutes before slowly releasing. Feel free to take a moment to relax before switching sides. Repeat this relaxing practice regularly, especially just before bed, to gradually release chronic hamstring tension.
4. Strengthen the gluteus maximus and hamstring muscles.
Remember that the gluteus maximus and hamstring muscles work together to create hip extension. One of the side effects of sitting in hip flexion for hours every day, as most of us do, is that the gluteus maximus muscles are chronically lengthened and the hamstrings chronically shortened.
Muscles work more effectively when they are able to easily contract and then relax; being stuck in one position prevents this from happening. The muscles then become almost “lazy”—more difficult to engage and less efficient when they do engage. Not only are the hamstrings trapped in a shortened position, they often wind up compensating for the “lazy” gluteus maximus. The hamstrings tend to respond to this overwork by becoming tight, tense, and irritated. Our natural response is to stretch them (as we frequently do in yoga), but as many of us have found, stretching irritated muscles can result in even more tension. On the other hand, strengthening the gluteus maximus and the hamstrings can help them to work more efficiently, reducing the tension and irritation that results from being in one position for extended periods.
In theory, we use the glutes and hamstrings every time we move a leg into extension (when we lift one leg from downward facing dog, for example), or move from hip flexion toward hip extension (as when we stand up from a forward fold or lunge). In practice, however, the body is very good at compensating for weakness and tends to instead use more dominant muscles—like the erector spinae down the back or the hip’s external rotators (the piriformis, gemelli, and obturators). This is why it can be worth isolating the gluteus maximus and hamstrings in an exercise like bridge slides.
Give it a try
You’ll need to be on a smooth, hard floor with a blanket or towel handy. Lie on your back with knees bent, right foot on the blanket and left foot on the floor. Position your feet and knees hip-width apart with your heels fairly close to your sitting bones. Press down into your feet to lift your hips and lumbar spine until your body creates a straight line from knees to shoulders. Adjust your feet if required to stack your knees directly above your ankles.
You’ll be using your gluteus maximus muscles to keep your hips lifted. Scooping your lower belly to lengthen your tailbone toward your knees should reduce the tendency to recruit your back muscles, while keeping the knees tracking at hip-width rather than letting them splay out should reduce use of the hip’s external rotators.
Come onto the heel of your right foot. Slide it away from you until your right leg is fully extended, and then use your right hamstrings to slowly drag your right heel back under your right knee again. Repeat five to eight times before slowly lowering your hips to the floor and switching sides.
If the exercise feels easy, try placing both feet on the blanket and moving both legs simultaneously.
Repeating this exercise every day or two for at least a month should help your glutes and hamstrings regain some of their natural strength.
5. Release your hip flexors and quadriceps.
Remember that the hip flexors and quadriceps on the anterior body are the antagonists for the gluteus maximus and hamstrings on the posterior body. The quads are commonly stronger than the hamstrings, yet yoga abounds with quadricep-strengthening work (think of the number of warrior and chair poses in the average class) and hamstring stretches (start with uttanasana and downward facing dog and continue down the list from there), rarely offering the reverse. Add that to hours of sitting and you quickly realize we are tipping the balance even further toward short, tight anterior muscles and weak posterior muscles. Over time, this imbalance pulls the pelvis forward, adding to tension on the hamstrings.
Working more often on gluteus maximus and hamstring strength will address one side of the equation, and regularly releasing the hip flexors and quads will address the other. It can be particularly helpful to choose a pose you can relax into for a longer period of time, allowing time for stubborn hip flexor and quad tension to gently dissolve; my favorite is the yin yoga pose half saddle.
Give it a try
Take a seat. Roll to your left hip, bend the right knee, and draw the right heel close to the right outer hip. Point the toes and rest the top of the foot on the floor, padding it with a small towel or an extra fold of your mat if required to feel more comfortable. Lean back on your hands, lifting your hips slightly so you can lengthen your sacrum toward the back of your knees; this slight posterior pelvic tilt is vital to lengthen all of the quadriceps and the psoas. If you already feel a stretch at the front of your right hip and thigh, make yourself comfortable enough to stay for a while, taking a comfortable position for the left leg.
Otherwise, recline back onto a bolster, stacked blankets or cushions, or the floor until you feel comfortable. If you feel pressure in your right knee, roll more of your weight onto your left hip; if you feel any pressure in your low back, create more posterior pelvic tilt (you may need to sit your hips on a half-sized block or firmly folded blanket to do so).
Position your left leg wherever it feels the most comfortable; rolling your bent left knee open (as pictured above) will soften the stretch down the right thigh, while pressing your left foot into the floor and pointing your knee toward the ceiling (as pictured below) will deepen the stretch.
Once you’ve found your ideal position, stay and breathe smoothly for three minutes or more. Repeat the stretch two to three times a week.
6. Balance your hamstrings and calf muscles.
Returning to our anatomical big picture, we’ve looked at the hamstrings’ synergists in hip extension, the gluteus maximus muscles, as well as their antagonists, the hip flexors and quadriceps. If we’ve examined these possibilities without creating happy hamstrings, it makes sense to also check in with the muscle that assists the hamstrings in knee flexion—the gastrocnemius.
The two heads of this superficial calf muscle attach on either side of the femur and run down the calf to form (along with the soleus, the deeper calf muscle) the Achilles tendon and then insert on the heel. We lengthen this muscle by straightening the knee and plantar flexing the foot (moving the top of the foot toward the front of the shin). This is why gastrocnemius tension can be one cause of heel lift in downward facing dog. If that sounds familiar, your gastroc may be tight enough to alter the natural relationship between the knee flexors, making it worth investing some time in calf stretches.
Give it a try
Place a rolled blanket or rolled-up mat parallel to a wall, about arms’ length away. Place one or both of your hands on the wall for support, and then stand with the balls of your feet on the rolled prop, letting your heels hang heavy so that gravity gradually draws them toward the floor. Keep your legs straight to focus the stretch on your gastrocs (rather than bending your knees, which would target your soleus muscles instead).
If this feels easy, play with recreating the same propped heel hang in downward facing dog or under the back foot in warrior I. Stay for at least three to five steady breaths, allowing the weight of your heels to gradually create length in your calf muscles. Repeat this stretch every day or two to see if rebalancing your knee flexors helps you release hamstring tension.
7. Restore healthy circulation.
In addition to being strong and flexible, healthy muscles are also well nourished by blood flow and free of fluid stagnation. Sitting on the hamstrings for hours every day can reduce their circulation. Reducing the time we spend in a sitting position, taking regular breaks from sitting, stretching in varied positions, relaxing chronic muscle tension by tapping into the parasympathetic nervous system and working on hamstring strength can all, in their own ways, encourage healthy circulation. Another potentially helpful tool is myofascial release—using targeted pressure to release muscle and fascia tension and encourage fluid exchange.
Give it a try
You’ll need two tennis balls or rubber massage balls. Sit with your legs stretched out in a narrow V shape in front of you. If that’s not comfortable, sit on a chair with a firm seat. Place one massage ball under each thigh, an inch or two away from your sit bones.
Either relax your legs or roll them gently side to side, leaning onto your hands or the back of the chair if that’s more comfortable for you. Stay a couple of deep breaths before moving the balls an inch or two farther down your legs, repeating the process until the balls are about two-thirds of the way to your knees. As the balls move down the backs of your legs, you can lean slightly forward to add weight, while focusing on allowing your legs to rest heavily on the balls rather than trying to find a stretch.
After two or three minutes remove the balls. Lie on your back, and see if you can feel any change in your hamstrings. Repeat this practice two to three times a week, stopping if you feel any pain or irritation. See if the extra stimulation helps your hamstrings to feel better.
Hamstring flexibility is commonly associated with yoga practice, but it isn’t the pathway to long-term hamstring health. It’s only when we see the hamstrings as part of a bigger picture that we are able to help them work in balance with all the muscles surrounding and opposing them.
Photography: Andrea Killam