Are Your Hip Flexors Tight? Or Is It Your Core?

In this post, we'll be talking about hip flexors and how they've often been demonized as always being "tight". Oftentimes people experience pain, discomfort, or a lack of range of motion in the hips and immediately attribute it to the hip flexors being restricted. Our goal with this post is to provide a bit more context, determine if it is actually the hip flexors or not, and provide solutions for if it is or isn't. But first, it's important to determine what hip flexors are in the first place, and why the term tight is often used in relation to them.

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Hip flexion occurs when you bring the top of your thigh up towards your stomach. There are a few muscles that participate in this action, namely the Iliopsoas (Iliacus + Psoas Major/Minor), Rectus Femoris, TFL, and sartorius. There are other muscles that also contribute to hip flexion, but these are typically seen as the major players of hip flexion.

First, let's define what "tight" means in this context. People often determine something is tight when there's discomfort, pain, or maybe even a lack of range of motion (ROM) or restrictions at a specific area of their body. Oftentimes they coin it as tightness because the area doesn't feel like it can move as much and sometimes can be relieved by stretching (even when it doesn't do anything productive in the long run). But this doesn’t actually describe the state of the muscle itself. Something can subjectively feel "tight" and be fully lengthened (overstretched). Something can be tight because it is in a shortened position and pulls you into a certain position. Or it can be tight because there is a trigger point present, instability, a recent injury causing splinting, etc. For the rest of this post, we will use "tight" to describe the hip flexors in being in a "shortened" position, which is what the goal of stretching the area would be to relieve, which is most often what the response to this sensation is regardless of what may be happening. Regardless of what may be the problem, oftentimes stretching or manual therapy is the go-to solution. These modalities are wonderful and can even help to mask the discomfort which can be beneficial in itself if it allows you to do an effective intervention pain-free, but much like a lock and key, we need to find the right key(intervention) for the lock (the root cause of the discomfort you are experiencing). Chances are if you are constantly stretching the front of your hip to no avail, your hip flexors are probably not "tight" or in a shortened position and you may actually be exacerbating the problem in the long term. But we can test for this by testing your capacity for hip extension. First, it may be advantageous to see how much active range of motion (AROM) you have in hip extension. You can lay face down, toes pointing to the ground and arms at your side. From here you will keep your knee straight and lift your whole leg off of the floor without moving or using your lower back. Image 1 Row 1 shows the correct way to perform it, while Image 2 Row 1 is the incorrect way, with an increased curve in the lumbar spine. We are looking for around 10 degrees of movement here. Next, we will check how much you have passively by doing another test called the Thomas Test. You will need a table or a high bench for this. But the pointy bones in your butt right at the edge of the table (Image 1 Row 2) and roll yourself back so you're lying face up with your knees in your chest with your butt towards the end of the table (Image 2 Row 2). From here keep your back flat against the table and lower one of your legs down so it is hanging off of the table, keeping the opposite leg in the same position. The main thing we are looking to see is where the knee is in relation to the greater trochanter (Bone on the side of your hip)(Image 3 Row 2). If the knee is above the greater trochanter (Image 4 Row 2), it could mean that the hip flexors are actually in a shortened "tight" position. If your knee is slightly above or even below the hip, but the knee is pointing straight out, that could mean that your Rectus Femoris (one of your quadriceps muscles) is in a shortened position (Image 5 Row 2).

Lastly, we will then look at the person's ability to maintain hip extension through movement. We will go into a split squat position (Image 1), testing both sides. If in this position, and while doing a few reps we find that the person needs to either create a large curve at the lower back (Image 2) OR has to bend at the torso and keep the back leg close to the front (Image 3), it could be another corroboration to our theory of someone having shortened hip flexors. If all of these tests come back negative, then we can be fairly confident that the problem may not necessarily be from hip flexors being short and tight, but rather from an inability to properly build Intra Abdominal Pressure (IAP)/brace the core through movement.

First, let's give some background: Our core is a hub of force transfer. Whether it be from an intrinsic force we are trying to transfer outward, or something external being brought internally, forces will almost always travel through the core to be transferred somewhere else or to be resisted. For this to be most efficient, managing IAP is crucial. IAP is the pressure that is built up in our abdomen and is increased when we go through inhalation. As we inhale, our diaphragm descends, decreasing the volume in the abdominal cavity and increasing the amount of pressure in the abdominal cavity. With inhalation, certain muscles are also being eccentrically loaded, most notably our "core" musculature. Oftentimes people have "dysfunctional" breathing patterns, flared ribcages, and lack of pelvic control, which can all set the stage for excessive force being put onto structures and muscles. This can show itself as having pain or discomfort on the anterior part of the hip, which we will see through looking at something called the conjoint tendon, and the two muscles that form it. The Transverus Abdominus (TVA) and the Internal Abdominal Oblique (IAO) are two important intrinsic core muscles that are responsible for lumbar spine stabilization, pelvis, and ribcage positioning and stability, forceful exhalation, and transferring force to and from the limbs. The TVA, along with the psoas, interdigitate with the diaphragm, making them inexplicably connected. As we inhale, the TVA and IAO are eccentrically loaded, as they oppose the diaphragm in action, putting them in a position to be more able to contract and often time stabilize. The TVA and IAO also come together to form the conjoint tendon which runs down towards the pubis. This tendon is fascially connected to the iliopsoas complex.


This fascial connection between the conjoint tendon and the iliopsoas can be used to help describe how proper hip flexion occurs when we are moving off of a stable and stacked core. Oftentimes people have poor breathing mechanics, flared ribcages, and anteriorly tilted pelvises, which set the stage for a poor build-up of IAP. When that happens, we can't get a full inhale, can't build sufficient IAP, can't properly load our core musculature which allows our hip flexors to move off of a stable core, possibly causing some sensations of discomfort through the front of the hip due to a lack of force being buffered centrally. Now, let's get back to core bracing. Core bracing involves using our breath to manage intra-abdominal pressure (IAP). As our diaphragm descends on inhalation, the volume in our abdominal cavity decreases, and pressure inside it increases, creating a closed container of pressure that our musculature can use to act on to stabilize the spine, transfer force to and from the appendages, and resist movement. On inhalation, the TVA and IAO are both eccentrically loaded, as they functionally oppose the diaphragm by being forceful exhalers. Being that these muscles form this tendon, once they are loaded on inhalation with an increased IAP, it sets the stage for hip flexion to commence, utilizing the pressure and tension built up to produce force. If we tend to fall into positions where we have flared ribs, an anteriorly tilted pelvis, and an inability to get a full inhalation, we won't be able to load these musculatures as efficiently, create sufficient IAP, and thus not allow our hip flexors to produce force in as efficient a manner as possible. If this happens, it is possible that we will have pain, discomfort, or tightness in our hip from improper loading or from our body sensing instability, causing it to reflexively tighten to limit movement.

 

From here on out we will talk about strategies for both scenarios - one for true hip flexor tightness, and one for improving core bracing and positioning. If 2/3 of the previous tests come back positive, this would leave us to believe that the hip flexors may be hypertonic, limiting the potential for a full excursion through hip flexion and extension. If we have limited hip extension, here are a few strategies that we can use to help regain that ROM.

  • Inhibit the hip flexors: If you are/have a manual therapist on hand, doing some sort of manual therapy to the Quads/Hip flexors can help decrease tone in those muscles and help set the stage for the hip extensors to produce force (Images 1&2). Working the TFL and even the lateral border of the Iliacus muscle can all be fairly easily achieved with a foam roller, lacrosse ball, or your own thumb. To target the TFL and Iliacus, find the pointy bone on the front of your hip called the ASIS. To get the TFL, go to the outside of the ASIS and press on the muscle that is there (Image 3). Turn your leg in and out to work it a little deeper. To find the Iliacus, go to that same bone, but instead, fall on the inside surface of it (Image 4). If you drop in half an inch, you will feel the belly of your Iliacus. Press it against the inside of the bone and flex and extend your hip.



  • Half-Kneeling stretch/Couchstretch: The leg that is being stretched is the down leg. Get your knee under your hip, engage your back toes on the ground, keep your ribs down and pull your butt down towards the back of your knee (Image 1). To increase the intensity of the stretch, shift your whole body forward (Image 2) while keeping your ribs and pelvis in line with each other. Images 3 and 4 show common faults while in this position. Keep your torso tall and don't arch excessively in your lower back. Image 5 shows a more advanced version of the stretch where you use a bench or a high box to put your foot on instead of having it be on the ground. The same principles apply as above.


  • Facilitate Hip Extensors: Now we want to activate our hip extensors. These do the opposite movement of what the hip flexors do. Now that we have inhibited the hip flexors, we want to give some permanence to the new length we achieved by getting our hip extensors to activate. This will also further help to decrease tightness in the hip flexors by a process called Reciprocal Inhibition. First, we want to start with the hamstrings. The hamstrings are the primary muscle in gait that bring the hip from flexion into extension. They also help set the stage for the pelvis by posteriorly tilting/maintaining a neutral pelvic position. Image 1 Shows a hamstring glute bridge on a bench. These will all be held for around 8 deep breaths w/ slow exhales through pursed lips. Go into a 90/90 position as shown with your feet up on a bench. Reach your arms up to the ceiling, bringing your upper back into the ground, while also keeping the lower back on the ground as well. From here apply heel pressure into the bench bringing your knees to the ceiling. Hover off of the ground so that your lower back is still on the ground. You can then progress this to the floor if the bench is too easy (Image 2). Next, we will get the glutes involved. Starting with the same cues as above you will hover off of the floor using your hamstrings. Once there, begin to bring the bottom of your glutes to the back of your knee, squeezing the glutes to do so bringing the hips towards the ceiling (Image 3). You should feel your glutes light up like a Christmas tree. Lastly, to add a layer of difficulty, we will do them single-legged. First, we will just tap one leg on and off of the bench for the duration of the breaths and then switch legs (Image 4). After that, we will hold the leg straight out instead of tapping (Image 5). For both of the single-legged versions, try not to rotate through the hips or torso. Load that one leg as much as you can and keep things in line as if you had 2 legs down.



Load and Go: Now that we have the sensorimotor competencies of what it is like to feel our hip extensors, it's time to load them and create long-lasting effects. We will look at the sled push, Dumbbell RDL, and Glute-focused hyperextension.

  • Sled Push: When done right, this is a great drill to train hip extension. We want to start in a position where our arms are locked out strong and our torso falls between the arms, as shown in Image 1 Row 1. When pushing the sled, you want to push off of your toes and fully straighten out the back leg so that you can draw a straight line from your hip to your foot. Also, be sure to land on your toes on the front foot to allow for a continuous toe-off for the next stride. Common mistakes in the sled push are starting with your arms completely bent (Image 2 Row 1), being too rounded through the back and not extending your pushing leg enough (Image 3 Row 1), or arching too much through the lower back and bending the neck up too much (Not shown).

  • DB RDL: The DB RDL is another great way to train hip extension and can be loaded up a substantial amount. Hold the dumbbells at your side, make sure that your ribs are down and that you aren't arching through your lower back. Imagine bringing