To state something that sounds obvious, our posture is made up of our whole body. When we hear the word posture, we often think about standing up straight. But how do we create that action of standing up straight? And what does that mean exactly, anatomically? In this article, I take a quick look at what posture is. And then I look at how tight hip flexors specifically affect our posture.
What is posture?
There are many ways to define posture. One general definition is the arrangement of our body in the field of gravity. A simple version of that is simply standing in anatomical position. That is the position of standing with our arms relaxed by our sides and our palms facing forward. If we think of that simple position, we might first go to the spine as the structure that primarily shapes our posture. And the spine is certainly involved. But if you think of where the spine attaches at the lower end, you arrive at the pelvis.
Remember that the base of the spine is the sacrum. And the sacrum connects to the pelvis at the sacroiliac joints. So, the position of the pelvis affects the position of the spine. And of course, the tension in the hip flexors affects the position of the pelvis. You see how complicated posture can get!
What are the hip flexors?
The muscles that fall into the category “hip flexors” include any muscles that contribute to flexing the hip joint. Some hip flexors are more primary contributors to that action than others. That is based on their location, attachments, and other actions they create. However, it’s easy to forget that muscles that flex the hip may also contribute to other actions.
Strong hip flexors, those that are primary contributors to that action, include:
- Rectus femoris (the other quadriceps only cross the knee joint, so they are not hip flexors)
- Psoas major
- Tensor fascia latae
There are also less obvious hip flexors that we don’t think about as much.
Other hip flexors that can assist with that action include:
- Adductor brevis
- Adductor longus
- Adductor magnus
- Anterior fibers of gluteus minimus and gluteus medius
All of the muscles listed above can contribute to the action of flexing the hip joint. But, remember, muscles don’t just do a single action. Each of those hip flexors also contributes to other actions. Some even contribute to the opposite action, depending on the position our body is in! This is important because when a muscle is tight, its other actions contribute to the way that tension shows up and affects posture.
How do hip flexors affect our posture, generally?
Our deep hip flexors, psoas major and iliacus, connect our spine to our pelvis. This is a pretty important connection! So you can see that the position of our pelvis impacts everything above it (through the position of the spine). The position of our pelvis also impacts everything below it. It affects how we carry the weight of our body and how we move it around (walk and run). For instance, if the pelvis tilts down and forward on one side (anterior tilt) it can present as a longer leg on that side. And that can add compression to the knee and foot below. Additionally, if one side of our pelvis is out of balance with the other side, all kinds of other compensations in the body can result. Sacroiliac joint pain and/or dysfunction is one common result.
What happens to our posture if we have tight hip flexors?
It depends on which hip flexors! Depending on which hip flexors are tight and the fiber direction of those muscles specifically, the tight muscles could pull our pelvis down and forward (anterior tilt). As we mentioned above, when one thing changes, the body has to compensate for this in some way. In essence, the body is always trying to get into balance around the gravity line. So, when the pelvis is tilted down and forward in the front, this means that the area above and in the back of the body also has to adapt. And this results in shortening the area around our lumbar spine.
The result of tight hip flexors also depends on what the balance is between those tight hip flexors and their antagonist muscles. If their antagonists are tight too, then you might have restricted range of motion, but might not notice as much postural change. In that case, some of the hip flexors might be tighter than we’d like but essentially in balance relative to their opposing muscle.
Why do our hip flexors get tight?
We sit and sit and sit some more. Instead of spending some part of most days walking over uneven ground like our ancestors, we mostly sit. That means we flex the hip joint and hold that position for most of our day. After some years of this, it can get harder to convince our body to let go of that holding when we leave a seated position. We can also tighten our hip flexors through our activities, like running or cycling. Additionally, in our abdominally-focused culture, people often do exercises to tighten their abdominals. And that will also frequently tighten the hip flexors.
What to do about those tight hip flexors
Ideally, we’d like to lengthen our hip flexors so we can return our pelvic position to something closer to “balanced” or “neutral”. But, if either sitting or an activity like cycling or running is causing our tight hip flexors, we might need to look at making some changes to our daily habits. Paradoxically, although sports like running can lead to tighter hip flexors, those same tight hip flexors can get in the way of good running form. So lengthening our hip flexors can support a more comfortable posture during our daily activities. And stretching out those hip flexors has the potential to improve our efficiency in some sports.
If we’re going to lengthen those hip flexors, we need to understand where they’re located. The hip flexors, like muscles that contribute to many other actions in our body, are layered. Rectus femoris is a superficial hip flexor, for example. It’s the hip flexor that is closest to the surface of our body. On the other end of the spectrum are psoas major and iliacus. Those hip flexors are located deep in the body underneath several other layers of muscles. We should be prepared to work with the superficial tight hip flexors before we get any ideas about lengthening the deeper layers.
A simple hip flexor stretch
My favorite way to stretch rectus femoris, and to some degree other hip flexors, is with a simple modified virasana. If you can, sit in a virasana position, but don’t worry about sitting between your feet. You can sit right on top of them or sit on top of a block. Place your hands behind you on the floor, then lift the hips as high as you can, and hold for 5-8 breaths. You should feel a stretch along the front of the legs. If you primarily feel it along the front of the knee, that’s okay. But modify the position as needed if you feel knee pain. Repeat this at least three times.
Where do tight hip flexors come up in our yoga practice?
The most obvious place we notice tight hip flexors restricting our motion in yoga is backbending. Any backbending posture, even an upward dog, stretches the front of the body. So, if we have particularly tight hip flexors, we’re likely to feel a stretch. In a deeper back bend, like urdhva dhanurasana, or wheel, very tight hip flexors may restrict our ability to do the pose at all. That’s when I suggest students incorporate the modified virasana stretch that I described above.
A less obvious place where tight hip flexors show up in our yoga practice is in the hips’ ability to rotate for poses like lotus and leg behind head. This scenario might be trickier to picture. In this situation, the hip flexors that we’re talking about are tensor fascia latae as well as some of those muscles that typically assist with hip flexion, like the anterior fibers of gluteus minimus and gluteus medius. If we have tension in those places, it can restrict our ability to extend our hip, just like tension in other hip flexors would. But, because these muscles do multiple actions, when they are tight that tension can also get in the way of our ability to externally rotate our leg at the hip joint. In that way, tight hip flexors can be the unexpected restrictors behind difficulty in lotus, leg behind head, and related postures.