On Wednesday, we discovered that the “Cinderella” of our hip flexors, the bi-articular sartorius, could be an over-looked cause of muscular pain at the anterior hip and medial knee.

Over and above an acute injury to the muscle, we should also consider how our postural and alignment habits contribute to sartorius-related pain and dysfunction.

Data from national surveys indicates that adult Americans spend 55% of their day in sedentary pursuits[1]. This translates into more than 7 hours a day sitting for many of us, an activity (or lack thereof!) that has been linked to a 49% increase of death from all causes and a whopping 147% increase in the risk of having a cardiovascular event[2]. As well as clearly having an effect at the metabolic level, sitting for seven or more hours a day certainly has an impact at the muscular level. Chair-sitting places the hips in 90 degrees of flexion, and spending a lot of our day in this position may shorten the muscles that connect the thigh to the trunk (psoas), the thigh to the pelvis (iliacus), and the sartorius as it works in the background to assist hip flexion. Considering that most of us also have the tendency to cross one leg over the other whilst sitting and we start to see side-to-side imbalances in sartorius muscle length.

Combine the lack of proper hip extension caused by shortened hip flexors with the inherent weakness in the muscles of the foot caused by poor footwear choices and a lack of ‘bare’ foot time, and even the time we spend out of sitting− standing, walking, and running− can lead to less than optimal loading patterns on certain joints and result in overuse injuries and pain.

If you are reading this, and feeling quite pleased with yourself as someone who has given up their chair and adopted a cross-legged position on the floor, then well-done for changing position, but consider again the actions of our forgotten hip flexor sartorius, that not only flexes the hip (and knee) but also laterally rotates and abducts the hip. Yes, that would be you, sitting with your legs crossed.

So to all your favourite hip flexor stretches, why not add ones that combine extension with adduction and internal rotation to specifically target the sartorius? To work on rehabilitating and strengthening a weak sartorius Half Happy Baby Mini Vini (as shown in the video below), will take your hip and knee through all the directions of movement required to correctly exercise your tailor’s muscle again and provide sartorius pain relief.

[1] Matthews CE, Chen KY, Freedson PS, et al. Amount of time spent in sedentary behaviors in the United States, 2003-2004. Am J Epidemiol 2008; 167:875-81.

[2] Wilmot EG, Edwardson CL, Achana FA, et al. Sedentary time in adults and the association with diabetes, cardiovascular disease and death: systematic review and meta-analysis. Diabetologia (2012) 55:2895–2905


Enjoyed this article? Read Awakening a Sleepy Gluteus Medius

Ali Bell

Ali was introduced to yoga by a roommate over 10 years ago – who obviously thought she needed it. As someone who biked all winter and ran and swam all summer, yoga became a bit of a life saver in terms of providing some physical and mental flexibility. Over the years yoga quickly began to surpass her interest in other pursuits – and some may say that is because the Scottish person in her truly appreciates how much cheaper yoga is than fancy running shoes. Since graduating from a 200 hour yoga teacher training program in 2007 (Bodhi Tree Yoga, Regina, Saskatchewan, Canada) Ali has continued on as a committed yoga teacher with an active physical practice and a keen interest in the anatomy and physiology of movement. Having been a keen follower of Jill Miller and Yoga Tune Up® since starting her journey as a yoga teacher, Ali completed the Level 1 YTU Training in October 2015. With a full-time day job as a Research Scientist for a local regional health authority, Ali continues to teach yoga part-time, infusing her classes with the science of movement and guiding people to be researchers of their own body.

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Urgh It is time I make these movements my focus! Thanks for all the great direction of movements in this article. It’s helpful to see it all written out like this. Great article.


This was a great video demo and I am
Excited to try it out! I had a situation where I had to sit for a long time and since then my hip has been driving me crazy! Thank you!

Julia Skinner

So many people have jobs that require sitting for long periods of time I’m glad you mentioned hip extension as well I think it can be somewhat ignored in favor of forward folds/hip flexion

Julie Heaock

As someone that has cranky hips, I enjoy Half Happy Baby Mini Vini. It’s interesting to see statistic about sitting for 7 hours. Thanks for sharing your insight.


The half happy baby mini-vini has changed how I feel about happy baby and my hips. I never liked the pose because I was struggling to get into it. Now that I understand how to break it down (and that it’s ok to do one leg at a time), I’ve decreased my hip pain and gained a new love for happy baby!

Patricia Maldjian

A friend of mine told me a number of years ago that “sitting has become the new smoking”. Reading blog posts like yours reaffirms the toll constant sitting can take on our bodies. I just began YTU training and learned this move today. Glad to have more practical insight into its benefits. Thank you!

Christine Lamborn

One more reason for Half Happy Baby Mini Vini!! Thank you for addressing Cinderella and giving her the opportunity to be center stage. Thinking in terms of the Sartorius gives a new dimension of awareness.

Rachel Taylor

I’m finding that placing an alpha ball between my thighs just above my knees is a great way to massage the sartorius near that medial knee attachment while I sit on a yoga ball (though I think it would work in a chair, too). I can work compression by adducting my hips to draw my inner thighs toward each other, cross-fibering by alternately lowering each knee toward the floor, and pin and stretch by squishing the ball between my legs and wiggling my butt side to side a little. It feels good as a way to massage the sartorius when… Read more »

Tari Surapholn

I like when you said “lack of proper hip extension caused by shortened hip flexors” make me realize how many hours I sit on the office chair and drive on the car. Proper movement/exercise to balance out my work activities to keep my hip happier is now on my bucket lists.

Dawn Williams

Ah! We learned this yoga tune up move today in our level one class and we’re told we’d find out more about what muscles this move helps. It felt great and too much sitting is why! Yea for movements that can help all of us who sit too much. Be it for work, driving or just relaxing a bit too much. Thanks for these articles on the Sartorius!

Louise Legouis

Thanks Ali for a good tip on a Sartorius targeting YTU pose. I’ll be incoporating more half happy baby minivinis in my routine.

Donna Layton

I think you just found one of my problems!!


Awesome insight. I just “discovered” this muscle in myself this week during my YTU training. I had been having pain in the medial side of my knee in a few “basic” poses and could not figure out why. As I started to learn a little bit more about what muscles move what joints in what direction – my book practically fell open to the sartorius. I’ve already began to find more range in these same poses without the pain by giving the sartorius a little love from the tune up balls!


Although so many of us do sit wrong and so often, seldom do we think about it or the consequences. Thank you for sharing techniques to help with this. Sometimes a reminder is all we need.

Peter Southall

Thank you for the reminder of how our routines can be potentially problematic

Amber Green

Amazing! Thank you for relating this to our everyday lifestyles in follow up to the previous article. I will be implementing Happy Baby Minivini into my daily practice since it involves multiple directions of movements in the hips because it is both an effective and efficient exercise to introduce into my busy daily life.

Catherine RL

From one article to the next about the Cinderella muscle I am fascinated. I cannot wait to create a class using the happy baby mini vini.
Thank you again

Amanda Shepherd

I think of “Hip Mini Vinis” as “flossing the hips”. My, rather open, hips enjoy the full range of motion, but I notice that students with less mobility get real benefit from them too (with a strap, of course) — no need to let your sartorius be a slacker. Thanks for sharing :).


Great article! It inspired me to take a closer look at the sartorius and create a class around this muscle.

Dejia B.

We did this minivini today in my L1 certification and I was shocked at how challenging it was for me – which just builds on my idea that my hip/knee pain could be related to the sartorious. Looking forward to continuing the work on this area and the surrounding areas to help heal my body, thanks again for the informative posts!

Linda Zanocco

Key to “Tree!” Ali, thank you so much for exploring Sartorius and relating it to Half Happy Baby Mini-Vini. I have a teaching cert. in Mat Pilates and did Level 1 training last summer + Roll Model Method Science and Sequencing last fall. I’ve been teaching RMM at a local yoga studio and plan to do Yoga Teacher Training in the fall. I’ve had several injuries and serious bunion on right foot that inhibit “Tree.” I’ve been working on it with the help of a 500 hour ERYT–1000 hour therapeutic yoga instructor as time and travel permit. I believe Half… Read more »

Amanda Burchert

Love the Happy Baby Mini Vini – frees the hips and erased my knee pain. Reading this article made me realize how often I sit with my legs crossed at my desk, something to really think about.

Stéphanie Marchand

For sure this exercice does really impact the sartorius with the the internal rotation. We are always using our legs in external rotation; even we are stretching them that direction too!! Balance is the key. I will use this technique with my group for sure!


I can honestly say that I overlook the Sartorius muscle often with hip or medial knee pain. I will not do that any longer. Thank you for the information, I will use Half Happy Baby mini-vini to help my clients when I assess sartorius is affected as well.

Laurel Crane

I definitely neglect my sartorius in my own body and there is absolutely an imbalance from side to side. I do enjoy this minivini and will try to find it in my movement practice more frequently.

Marie-Pierre Gauthier

Thanks for the article, I have pain when I cross my leg.
I’ll do more 1/2 happy baby pose!

Natalie K.

Thank you so much for sharing this, Half happy baby is a pose that I struggle with and I never even thought about the Sartorius!


Half-Happy Baby Minivini is my favorite yoga tune up pose. I sit much of the time for my job whether it is at a desk or driving. This pose really opens up my hips and loosens up the shortened hip flexor so. Thanks for the great article!


love it.. thanks


Loved the article and will be trying half happy baby like in the video. I do sit a lot..car, computer, studying, reading etc.


I didn’t know that the Sartorius (bi-articular) could be a cause of muscular pain at the anterior hip/medial knee. This has been a very helpful article, the Half Happy Baby Mini is more challenging for me and now I know part of why.


I definitely agree that the sartorius is the forgotten stepsister highly involved in hip extension inhibition because of it’s role in flexion and the habits of today’s sitting/sedentary society. Alongside Happy Baby Minivini, the Buttocks Lifts Minivini is a great workout to challenge the core and strengthen the hip extensors- glutes & hams.

Claudia Muehlenweg

I never liked Happy Baby or the mini vini due to compensating in the lumbar spine (I cannot do Happy Baby unless i curl up the tailbone or just grab my knees). But as a teacher said to me, a long time ago, what you don’t like is what you need. I guess the Happy Baby Mini Vini has to go on my daily playlist 🙂

Lisa Federico

Thank you Ali for an informative path to half happy baby…one of my favorite poses. I remind my clients and myself…several times daily to uncross the legs


Sit in a chair, sit on the floor, stand, squat…just gotta mix it up! And, of course, throw in a Half Happy Baby Mini Vini every once in a while to cover your bases.

Genea Crum

As a yogi with many hip issues, I love the half happy baby mini vini. It isn’t always easy or comfortable but more often than not gives me some relief from my hip discomfort. Good reminder to sit less and move more.

Rachel T.

I knew I loved this mini Vini for a reason! Sometimes the body know what it needs even when the mind doesn’t and this 3direction hip flow certainly allows. The only issue I have this with is your hips are still in flexion most of the time still just as they are in a chair. Adding a hip extension/quad stretch pose after this would REALLY move the hips in all their directions….Yay hip mobility!!!!

Cintia Hongay

Happy baby or 1/2 happy baby are very difficult poses for me. Perhaps it is my sartorium… never thought of it. Thank you for a very detailed article. I will give my sartorium the TLC it needs!

Juliana Attilio

I’m so glad to see 1/2 happy baby minivini for sartorius self-care. It’s one my favorite movements and I think so many people are overlooking their sartorius. So I now have another great reason to include this minivini in my classes!

Adriana Robertson

Thanks for sharing this useful information. I recently learned about the half happy baby minivini but didn’t fully understand which muscles it was working. Great to know that this exercise targets the sartorius and help lengthen it to create more balance in the body if it has been shortened.

Diana Germain

Thank you, this is a muscle I am going to pay more attention to as well as I continue to work on strengthening and bringing greater stability and balance into my hips. In particular, I need to pay attention to strengthening these muscles because I have a labral tear that now requires surgery. I’m pretty sure it came about in the first place in part from dysfunction and imbalance.


I don’t have a desk job but I do cross my legs a lot, I never thought of the sartoris in this way! Thank you for brining it to light!!!

Carol morgan

Love this article. I decided to get a “standing desk” so that i was not compromising my body with hours of sitting and bad shoulder positions “mousing” The focus has to be keeping a good posture though, good alignment, and always shifting around so as not to get stuck in one position. This also puts you in a great position to do some shoulder flexion, knee bends, and just loosen up and stretch while you are standing!

Erin Hoien

I love Moon Rises – but mostly I’ve focused on the femur bone and how it feels moving around in the socket and my Glute Med. As my focus shifts to the actions of the sartorious, I will think of these wonderful blog posts and perhaps the find that missing link that has left a little residual discomfort.

luciana gorga

thanks for this article . very interesting to know the effect of the sedentary life and the incorrect posture and the relationship in the hip flexor and the sartorius. The half happy baby mini vini is my favour approach.

Keiko Johnson

Very concise description of this amazing muscle and some of the main lifestyle issues the ordinary person suffers through to unintentionally challenge it. Will definitely share with a friend who is suffering with a long commute and a long sit all day.

Kyrin Hall

Thanks for the reminder that simply switching from sitting (all day) in a chair to sitting on the floor in a cross-leg position will not strengthen a weakened Sartorius.

sarah howard

Love your article. I just did the “happy baby mini vini” this morning and after reading your post about the sartorius I know a bit more about what muscles I am strengthening/lengthening while doing this mini vini! Thanks!

Simran Khalsa

Great! I have identified the pain in my knee and a way to find relief. Thank you.