Stretching for athletes: Kneeling hip flexor stretch

I absolutely hate those articles where the title lure's you in all click-bait-y, you click it and then they don't give you the answer or they give you half an answer right at the end. This is not one of those articles.

The world's greatest stretch is the kneeling hip flexor stretch.

Hips at 90 degrees, poke your butt back, then posteriorly tilt the pelvis, tuck the tailbone under, draw the belly button in, contract the glute of the rear leg and move forward gently into the stretch.

It's a bit uncomfortable, it's tricky to get right and it takes a bit of explaining as to why it's so important.

It's a little muscle on the front corner of your hip. It flexes and internally rotates the femur putting it into a valgus position and it hates sitting with a passion, if you so much as look at a chair TFL is already starting to lock up.
Consider it the arch nemesis to your superhero duo of glute max and glute med.

When I posted that video what I said was; "If Bane was TFL, then The Joker would be the psoas." But that's not 100% correct. So, the Psoas is a more complex character than The Joker, kind of has goodness deep down in his heart but also with that huge streak of evil, using his or her positive social standing as the platform for ultimately doing evil. It has a good side and evil side. So it's not exactly the Joker, it's more like Two-Face or Talia Al Ghul.

OK, now a little anatomy. Psoas can be a bit tricky to grasp because it sits inside the abdomen and really needs to be seen in 3D:

Psoas attaches to the anterior of the lumbar vertebrae from L1 to L5. It then runs under your abdominal organs, across the top of your pelvis and attaches to the front of your femur. The function and action for psoas are actually very similar: Flexion of the hip (particular emphasis on hip flexion above 90º when rec fem isn't as able to help)

No psoas = no knee-drive and no sprinting speed, no triple flexion.

But then, plot twist, Psoas feels undervalued or betrayed and turns evil with one hell bent goal of destroying ~Batman~, your posture and athletic potential.

Because we spend so much of our life sitting, the psoas basically lives its entire life in a shortened position. Over time, because muscle adapts to the stimulus you place on it, the psoas (psoas's?) will gradually shorten and tighten, bringing you into an anterior pelvic tilt.

Let's dig a little deeper into what's going on here.

Most of the muscles in our body work in pairs. The biceps and the triceps, for example, they work in complementary opposites, one flexes while the other extends the elbow. But for that to happen, the nervous system has to coordinate and control the flexion and extension timing/rhythm so while one is being turned on the other is chilling out and being inhibited.

If the non-working muscle (it's called the antagonist) didn't chill out and they both tried to contract together, we'd all be either A) frozen solid and unable to go anywhere or B) the muscles would rip our joints and each other apart in the battle for movement.

This rule is called "reciprocal inhibition".

The Psoas (as a hip flexor) lives in a pair with your glute max (the primary hip extensor). If that psoas becomes chronically short and tight from all the sitting we do, the nervous system recognises that tightness as activation (which in a way it kind of is), like a tonic muscle that I talked about in the trigger point episode.

Over time, that tightness and hyperactivity through the psoas (psoases?) will shut down the nervous systems ability to fire and activate our glutes fully, making for a more chronic version of the biceps vs triceps example from before.

That's why this stretch, the kneeling hip flexor, is the world's most important. Removing that literal reciprocal inhibition handbrake and allowing the glutes to activate fully, return your pelvis to a normal alignment (and take some stress out of your lower back), defeating the bad guy and taking back Gotham City.