Core Series: Hip Flexors

The hip flexor is actually made up of 2 different muscles: Psoas Major/Minor and Iliacus.


I like color-coded things.

As you can see, the Psoas muscle comes from spinal attachments. And Iliacus comes from internal hip boney attachments. So why are they “iliopsoas”, one muscle?

Because they essentially fuse once they cross the hip joint.

BUUUUUUUUUT, this makes it that much more complicated of a muscle group where core work is concerned.

A weak or tight psoas muscle can cause one side of your pelvis to tip forward. This is called an anterior innominate and it ain’t right.

Yeah, but only on ONE side. OUCH.

Yeah, but only on ONE side. OUCH.

It can also cause a twisting motion to happen because the muscle attachments are at an angle from the spine to the hip. Double ouch.

The Iliacus is a whole different beast. It attaches on the inside of your hip wing (Ilium) and then shares a common attachment with the psoas on your femur (thigh bone) at the lesser trochanter.


The green colored spots are the lesser trochanter on the medial (inside) part of your femur (thigh) bone.

Can you see how if these muscles are tight or weak that they might affect your core? And your gait, right? Huge. These two muscles are not just straight up and down and they have big jobs in multiple movements of the trunk and legs.

Here’s how to keep these hip flexors happy and healthy:

1. Pelvic tilts (Beginner)

Lying on your bed or another soft, level surface, place a pillow under your knees. WITHOUT PUSHING INTO YOUR FEET (tip, put something under your feet that you don’t want to crush, ie. your phone), draw your belly button toward your spine. Slowly return to neutral.

Neutral spine (slight curve is natural)

Neutral spine (slight curve is natural)

Spine curves and belly draws down to create a concave curve.

Spine curves and belly draws down to create a concave curve.

Repeat 10 times WITHOUT SQUEEZING YOUR BUTT. And remember, don’t put any weight in your feet.

2. Heel slides (Intermediate)

Lying on the floor with your socks on and knees bent, slowly allow one leg to straighten and pull it back to being bent WITHOUT LETTING YOUR HIP HIKE. You can place your hands on your headlights so you can feel them move.

Start with your leg straight.

Start with your leg straight.

Slowly drag your heel toward your butt (no weight in your feet!)

Slowly drag your heel toward your butt (no weight in your feet!)

NO HIP HIKING (this is hip hiking)

NO HIP HIKING (this is hip hiking)

This is what your hips should look like. No hiking. Totally level.

This is what your hips should look like. No hiking. Totally level.

How not to let them move? Suck your belly button in and go slowly.

3. Straight leg raises (Advanced)

Lying on a flat surface with one leg straight and one knee bent, lift your straight leg as high as you can WITHOUT PUSHING INTO YOUR FOOT OR HIKING YOUR HIP.

Start with your leg straight.

Start with your leg straight.

Only go as high as you can go WITHOUT HIKING YOUR HIP.

Only go as high as you can go WITHOUT HIKING YOUR HIP.

Doing these exercises correctly is the key. You can do this stuff and throw your leg around easily. BUT can you do it without hiking your hip or squeezing your butt?

If you feel wimpy for doing just the pelvic tilts, don’t. They are like the ballet of hip flexor exercises. You have to perfect and maintain your form with the pelvic tilts in order to do ANY other hip flexor exercise. This is why I suggest doing them no matter how strong you get.

(PS. All my new moms NEED to be doing pelvic tilts and heel slides, especially C-section mamas!)

Let’s make strong, happy hips, shall we?

Now go out and run!


Core Series: Hamstrings

Hamstrings…not exactly the muscle group you think of when someone says “core”, amiright?

  1. Biceps femoris
  2. Semitendonosus
  3. Semimembranosus
The problem children of runners the world over.

The problem children of runners the world over.

I kept that picture HUGE so you can see all the little details. See how the hamstrings attach to the bottom of the pelvis (called the ischial tuberosity–please STOP CALLING IT A SITS/SITZ BONE) and then shares an attachment site with the sacrotuberus ligament that attaches to the sacrum?

Here’s the point: tight hamstrings are more than just a pain in the leg. Tight hamstrings can pull your pelvis downward, causing a posterior pelvic tilt. What does that mean? Low back pain and asymmetry. Remember my 3 S’s? Strength, stability, symmetry. Asymmetrical –> injury.

So, tight RIGHT hamstring can also put too much stretch on the RIGHT hip flexor, causing a tension reaction (also can indicate a weak RIGHT hip flexor) and mess up your gait when you walk and run. It’s also just painful.

How to strengthen it?

You can do basic hamstring curls, but that’s not very practical in everyday use. My favorite exercise: Physioball Roll-ins.



The key part of this exercise is to lift your butt and KEEP YOUR HIPS AT THAT HEIGHT while you bend your knees inward. If your hips go up or down, you lose the exercise completely.

It’s hard, I know. If it’s too easy for you, check your form. The strongest of athletes can’t do this exercise without wobbling.



For those of you who need a less strenuous hamstring exercise, there’s the Standing Leg Curl. They key part of this exercise is to make sure your bending knee’s hip doesn’t dip as you lift your foot. Standing against a wall or a table will assure your hips stay level when you do it.

Most importantly, SUCK YOUR BELLY BUTTON IN and stick your chest up and out to activate your other core muscles.



You can add an ankle weight or a Theraband with cuffs when you get stronger.

In order to perform these exercises and get a benefit from them, I recommend starting with only a few reps (2-6) for 3 sets. Only do as many reps as you can maintain perfect form. Stop as soon as your form goes. Rest. Try again after a full minute.

Now go out and run!

Core Series: More Than a 6-Pack

I am going to start a movement. It’s the True Core Movement.

Most people think of the core as being the abdominals. Some are knowledgable enough to know that the core includes the back muscles. A few think about glutes as a component but few, if any, consider the adductors, hamstrings, middle back, or quadriceps when thinking about the core.

If you only consider the abdominals and the back muscles to be the core, you’re missing out on the larger muscles that can make or break your core stability.

Glutes >>>> Abs, Back, everything else

Glutes >>>> Abs, Back, everything else

And a strong core isn’t primarily about strength. It’s about stability and symmetry. I really should go ahead and trademark my 3 S’s theory before someone else does, but I don’t know how. Do you? Tell me.

And when thinking about the core, if you focus on muscles, you’re thinking too small. Think BIG. Think hips.

Like Shakira says, hips don't lie.

Like Shakira says, hips don’t lie.

Any muscle that touches any part of the hip girdle or sacrum is part of the core. And any of these muscles can GREATLY affect your ability to maintain strength, symmetry, and a stability. It will also directly affect whether or not you get injured, your ability to run faster, and how much energy you require to run.

And these muscles will change the symmetry of your hips, directly affecting the strength output and stability of your entire body. Whoa.

Big. Freakin. Deal.

Hahaha! Remember this? Oh, Biden.

Hahaha! Remember this? Oh, Biden.

So, in this series, we’ll talk about all of these muscles and how to keep them on point to make you a stronger, faster, less-injured runner. If you bookmark these posts, you’ll have a great program for strength training that covers all your pelvic core muscles.

Just a thought.

Are you excited? I’m excited. Let’s do this.

Now go out and run.