Fold Forward

Sun Salutations – Part 3 – The Forward Fold

David Keil Yoga Postures 7 Comments

All you have to do is forward fold!

In part 2 of this series we looked at the relatively simple task of raising your arms over your head. Now we’re going to look at how simple it is to forward fold after raising those arms. All forward bends are connected as I wrote about in the Anatomical Patterns in Forward Bends chapter in my book, Functional Anatomy of Yoga.

Of course, like everything, as we look more closely, we see the complexity of how things interrelate and function…especially when we’re talking about the human body.

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Where do we forward fold from?

Well, let’s start with the simplest answer to that question. We fold forward at the hip joint of course. (The spine also flexes, but predominantly the movement is at the hip.) What action is happening at the hip joint? It’s flexion of the hip joint.

What muscles work when we flex the hip joint to fold forward in a sun salutation?

I’m going to pause here for a moment and just waste a little time while you’re reading these words to see if an answer has popped into your mind. Did one? The most common answer to that last question is that it’s our quadriceps or other hip flexors that bring us into hip flexion.

It seems like reasonable and sound logic, as we are flexing the hips. The hip flexors must be the ones that are contracting to take us down into that forward fold. But in this instance, that logic is flawed. One of the most common elements people forget to include in their basic understanding of movement and function is gravity.

The truth is it is our hip extenders that are lowering us to the floor. They are doing what is called an eccentric contraction. In other words, the hamstrings are the primary resistance to us rapidly falling to the floor. Gravity is doing the work; the hamstrings are resisting the weight. The hamstrings are both contracting and lengthening at the same time.

The spinal muscles are involved as well. They are part of that back line of tissue and contract to help stabilize the spine as our torso is lowered toward our thighs. Both the hamstrings and the spinal muscles have a tendency to be “tight”. The question I ask is: Are we taking advantage of that tension in a strength way, or are we exacerbating tension and either making the areas tighter, or making our way into dysfunction?

As we’re about to see, there are options when folding forward. You will have to decide which is most appropriate for you in this moment.

Bending your knees vs. keeping them straight

At this point I would say there are two basic options. Neither is absolutely right or wrong, they just create different effects. Feel free to do whichever is more appropriate for your body.
The first option is to keep the legs straight and it’s probably the more common choice. With the knees straight the hamstrings have to work, mostly by themselves, to prevent the forward fold from giving into gravity completely.

A secondary effect of folding forward with straight legs is that the hips have a tendency to move back behind the ankle while folding forward. This by itself is not harmful or detrimental. It’s probably a good compensation that relieves some of the potential stress on the hamstrings. This is especially true depending on what you’ve done with your arms while they are making their way down to the floor. (If your arms are above your head, there is more weight for your hamstrings to manage. The closer they are to your body, the less weight there is for them to manage.)

sun salutations forward fold knees straight

The above image is with knees straight. The line gives a reference relative to the ankle and how far back the pelvis moves during the fold.

sun salutations forward fold

Notice where the hips are relative to the ankle using the red line.

The second option is to bend your knees. What does bending your knees do and how much bend are we talking about?

The answer is, it really doesn’t have to be much of a bend. But let’s be clear, we are specifically talking about bending the knees while moving. I want to stress that, because I am a firm believer that too much bending of the knees, along with some other patterns, can lead to a pain in your butt, literally. However, having your legs straight can lead to pain as well. Sit bone pain is still one of the top search terms that brings people to I am a believer in straightening the knees (if possible) while IN a forward fold. I am in favor of a slight bend while MOVING into a forward fold (while standing).

Sun Salutations forward fold knees bent

With the knees bent the pelvis does not have the need to move so far back and weight is distributed into the legs.

sun salutations forward fold knees bent

In the forward fold, the hips can line up with the ankle and weight pours into the hands.

Having said that, during movement itself the effect of bending the knees slightly is that you:

  • Take advantage of the entire chain of joints in the leg
  • Reduce the body weight supported by the hamstrings
  • Distribute the weight through the entire leg

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The chain of joints in a forward fold

Keep in mind that your leg is a functional chain. By that I mean that all of the major joints, ankle, knee, and hip, are interrelated. If we bend the knee in this case, both the ankle and the hip joint itself will have to change. By change, I mean, they move and therefore recruit muscles around those joints to help stabilize through this movement (There is more detail on this in my book).

By recruiting these other muscles the amount of weight that the hamstrings have to support is significantly reduced. The hip is more likely to be able to stay in alignment over the ankle when there is a slight bend of the knees during the folding movement. This is because the hips aren’t compensating for the weight out front by moving backward over the line of the ankle. This then leads to the weight being distributed through more muscles in the leg. Instead of relying on, and “tightening” those hamstrings, other muscles can now help support and stabilize the movement, i.e. gluteals and quadriceps.


There is still further to go with the end of this movement. When we put our hands on the floor and fold followed by the looking up movement, we are going to see that our hamstrings and back muscles are in the game again. Where should we put our hands anyway? Should they be flat or should we be on fingertips? Let’s look at this piece of the sun salutation next month and prepare for the very important jumpback that we are about to see.

Comments 7

  1. I’m curious about protecting the wrists here – I keep injuring the long tendon (?) that goes under the thumb mound and up into the arm. Sometimes it flares up just doing this – let alone jumping back Any view?

    1. Post

      Felicity… We would have to see what you’re literally doing. We have to consider that there is something that you’re brining to this already, like, iphone use, typing, other activities that are loading the thumb with stress. It might just be that this is showing you that, rather than causing it directly. We don’t know and certainly won’t figure it out over the internet.

      The next piece will be on the lift up and jump back.

  2. Thanks David – I’ll wait for the jumpback piece with eagerness. I’ve put a lot of mat time (& anatomy research) into trying to correct the way I used my forearm and shoulder on the troublesome thumb side. I was putting maybe 20% of my weight through the weak side and 80% through the other, I realised (after about 1 year of jumping back at all), so I guess its the never ending and mysterious journey. Could not have done it without this site too!

  3. Pitching the pelvis back with straight legs, in some bodies isn’t this promoting knee hyperextension = sleepy legs, risk for injury to the hamstrings? Also, for the average practitioner who has limited flexibility in the hamstrings, won’t straight legs be tugging on the pelvis posteriorly, taking away from true hip flexion and causing lumbar flexion? Appreciative to hear your thoughts 🙂

    1. Post

      Hi Ashley,

      Yes… and yes. I’m not sure if you read this article and understood that I was promoting this way of forward folding or not though. I often tell both sides of a story and let people choose for themselves, unless they’re in my class and working on something specific. Having said that, yes, straight legs can lead to pelvis posteriorly tilted and more flexion in the spine. I’m more of a fan of bending the knees and leaning forward as you fold.

  4. So the question is why would we want to do this pose at all. As you stated,
    “However, having your legs straight can lead to pain as well.” why are we still promoting this pose? As well you stated “I’m more of a fan of bending the knees and leaning forward as you fold.” I have only seen the front cover of your book, so why are you showing the seated forward fold with straight legs and hyperfexion of the whole back instead of promoting bending knees that allow for easier hinge at the hips, and saving some backs in the meantime.

    1. Post

      Hi Mauro,

      First, thank you for commenting. You ask, Why do we want to do this pose at all?

      How else do you intend to lengthen your hamstrings.

      This site is definitely not about removing postures completely, it’s about understanding that different bodies may need different ways of doing things. Many people believe that straight legs is the only way. Others, that you have to keep your knees bent. Neither of them are right all the time. What’s important is to look at the student, let go of dogma, and see what works for them.

      As for the book cover, I think you are mistaken, the cover has a handstand on it. It’s possible that you saw an image of a forward bend with straight legs and hyperflexion, but without the context of the book, you are missing something. In this case, probably the next image which is with bent knees and a straight spine.

      Context is everything. For instance, in regards to throwing away a forward bend… What is the percentage of people who do this every day with no problem at all? My guess, above 90%. So… should we throw it away based on 10% or do we ask that 10% to explore and change the way they do things?

      Thanks again for posting…

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