How Hip Anatomy Affects Squat Mechanics


As coaches we often have a standard set-up for teaching the barbell squat. Toes should point out slightly, feet should be placed at shoulder width and everyone should squat below parallel. Unfortunately this doesn’t always work. No two people will squat exactly the same way. There is no “one size fits all” approach to squatting.

Before we start, it should be said that this is not the first time this subject has been discussed in depth. Dr. Ryan DeBell of The Movement Fix wrote a great article previously that discussed how hip anatomy can easily differ between people. At Squat U we are trying to complete a comprehensive guide to squatting. Some of you have read Dr. Debell’s article, however many of you have not. Omitting our take on hip anatomy would be a disservice to people who want to learn more about squatting.

There are two main factors that dictate how well we squat.

  • Mobility – the pliability of our soft tissues (muscles and fascia) and how it affects how we move. When our tissues become stiff or shortened, they can hinder our ability to move well. This is one of the reasons why sitting for 8+ hours a day is so harmful to the body.
  • Anatomy – the way our bones are formed and aligned. It shouldn’t come as a surprise that you have a different bone structure than your best friend (or anyone else for that manner).

We have previously addressed hip mobility in one of our past articles. By addressing stiff tissues we can easily improve our technique. For this reason, “mobility” has been has become a popular buzzword in recent years.

However for some individuals, they just can’t seem to perfect the ass-to-grass squat or achieve a flawless pistol squat no matter how hard they try. For some people, no amount of mobility work will change their squatting mechanics. When an athlete has a problem with their squat due to their anatomy, they will always be fighting an upward battle. This will be apparent when we have a closer look at the hip joint.

Anatomy 101

The hip is basic ball-and-socket joint. The end of our thigh bone (femur) is shaped like a small ball. It fits within the “socket” (acetabulum) of our hips.


 Individual Differences (Hip Socket)

 However, not everyone fits this “textbook” bone structure. Variations in the way our hips are formed will impact how we move, especially with the squat.

In 2001, a group of researchers from Japan took a close look at the hip joint. While a large majority had “normal” hip sockets, close to 40% of those examined did not (1). Let’s take a look at a few photos that show how dramatic these differences can be.


In this photo you can see two totally different socket shapes. The socket of the left hip points forward and has a sharp angle. On the right, the socket opens laterally and has a curved shape. According to research, there are actually 4 distinct shapes the socket can take (1).


Now take a look at the hips from the front. With this view, you can see again a dramatic difference in the alignment of the sockets. The hip on the left has the sockets pointing forward meanwhile the hip on the right opens more laterally. This difference alone will have a significant impact on how a person squats.

Individual Differences (Femur Shape)

Some people also have variations in the way their femurs are shaped. For example, some of us have femurs that are twisted forward or backward. This will affect the alignment of the femur in the hip joint. A more angled femur (right) is called an anteverted hip. A flattened angle (left) gives us a retroverted hip (2).


 What is anteversion?

In order for a femur with an excessive angle to fit correctly inside the hip socket, the rest of the thigh must be rotated inwards. For this reason, athletes who have this type of hip will appear as if they have an excessive amount of internal rotation and a little amount of external rotation.Hip Rotation.png

While some athletes with anteversion will show the classic “pigeon toes” alignment, this isn’t always the case. In order to keep their toes from pointing inwards the lower leg bones (tibia) will often adapt. The tibia will form an outward twist to compensate for the inward twist of the femur. The body adapts and tries to keep the feet pointing forward when possible.

tibia torsion.png

For this reason, it is very hard to know if someone has a natural twist in their bones by just looking at them. Forcing an athlete to conform to the ‘ideal’ squat technique when they have this type of anatomy can be disastrous. If an athlete reports feeling uncomfortable with their squat stance no matter how much mobility work they do, they should be screened to see if their anatomy is preventing their progress.

How to Screen

Checking the hips often starts by assessing the amount of rotation available at the joint. With an athlete on their back it is easy to see how much internal rotation (foot moving away from the body) and external rotation (foot moving toward the body) an athlete has.

While this is a great way to assess possible mobility restrictions, it doesn’t give us a great idea of what’s going on with our bony anatomy. If there was a large difference in the amount of internal vs external rotation on the same leg we need to assess what’s going on inside the hip joint. To screen the anatomy of our hip we need to use Craig’s Test.

Start with the athlete lying on their stomach with their knees bent at 90°. Take your hand and feel for the where the notch of the femur (greater trochanter) is located. With your other hand, begin rotating the athlete’s lower leg in and out. As you rotate the leg you’ll begin to notice the notch of the femur becomes more and less prominent against your hand. Stop moving the lower leg when you find this position to be most prominent.

Ideal or ‘normal’ anatomy will leave the lower leg pointing only slightly away from the body (within 15° from a vertical position). If the athlete has their lower leg now positioned at a large angle, they have a possible anteverted hip. This method of assessing hip anatomy has been shown in research to be extremely reliable (even better than taking an X-ray) (3).

What Now?

If you have a positive Craig’s test you may be asking yourself, “What does that mean for my training?” Individual differences in anatomy like this will affect both foot angle and width of your squatting stance.

Some athletes can naturally squat with a wide stance. Others (especially those with hip anteversion) will have to squat with a narrow stance. Some athletes will be able to squat with their toes straightforward and others will have to turn their toes out at an angle in order to reach full depth.

An athlete’s stance should be dictated therefore by comfort. They need to feel stable with whatever stance they take and they should not have a pain. Athletes who try to conform to a squat stance that is not right for their hips will feel a hard blocking sensation or a pinching pain in their hips that is unrelieved with mobility work. This is your body telling you to move differently. Listen to it.


If you have excellent squat form, congratulations. However, if you struggle to perform a squat with perfect technique (even after hours upon hours of mobility work) it may not be your fault. Some of us are born with the ideal skeleton for deep squats. Some of us are not. Just because anatomy may not be on your side doesn’t mean you should just hang up your weightlifting shoes and quit trying all together. You only need to understand what works for your body and make the right adjustments in order to reach your potential and stay pain free,

Until next time,

Dr. Aaron Horschig, PT, DPT, CSCS, USAW


Dr. Kevin Sonthana, PT, DPT, CSCS








**All bone images were used with permission from Paul Grilley

The Squat Fix: Hip Mobility Pt 3

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Welcome back to Squat University! During these past few weeks we have covered the hip joint. Previously, we introduced a screen to test our hip mobility called the Thomas test. Most restrictions are due to either joint immobility or soft tissue tightness (stiff muscles and/or fascia). The goal of this weeks lecture is to introduce a few simple tools to address these restrictions.

Today I wanted to share a few of my favorite tools. I also want to share with you my 4-step process in dealing with hip stiffness.

  1. Mobilize
  2. Foam Roll
  3. Stretch
  4. Posterior-Chain Activation


Hip Mobilizations

A restriction in joint mobility should be the first area to address. During the Thomas test, a “pinching” sensation felt in the front of the hip when pulling your knee to your chest indicates possible impingement. This sensation is felt when the femur hits the joint “blockade,” halting the movement at the hip joint. These types of restrictions will not resolve with conventional stretching and foam rolling. Therefore, any pinching sensation in our hip joint must be addressed first before moving onto possible soft tissue stiffness.

One of the easiest ways to improve joint restrictions on your own is to use a band for mobilization. The rubber material of the band is elastic and strong enough to affect the tough joint-capsule of the hip. If you don’t have access to one, I’d check out the Superband from Perform Better.

Band distraction joint mobilizations assist with the way our bones glide over each other. A joint glide is sustained while the athlete actively moves into the specific range-of-motion we are trying to improve. During the squat, the end of our femur glides backwards in our hip joint as our thigh moves towards our chest. These types of mobilizations (simply termed mobilizations with movement) have been used for years by physical therapists. The goal is to alleviate any painful or pinching feelings deep in the joint.

Physical Therapist and founder of MobilityWOD, Kelly Starrett gives an easy explanation for this banded mobilization.


Foam Rolling

Once joint restrictions have been addressed the next step is to clear up any soft tissue stiffness. This starts with using a foam roller. I usually recommend athletes spend at least 2 minutes on each area they are trying to address. Every athlete should foam roll on a daily basis!

Our goal with the foam roller is to decrease the stiffness the Thomas test was able to expose. This means addressing our hip flexors, quads, and lateral hips. Start by moving slowly up and down the lower leg muscles until you find a tender area. Pause on this area and ‘tack it down’ with your bodyweight for ~10 seconds before moving again.

I like to use the analogy of kneading bread with a rolling pin. You want to use the foam roller to knead your tissues, rolling back and forth in small rhythmical movements. Lying on the roller and moving quickly in large passes will have little effect on your stiff tissues. You can also add in active knee movement during this pause to increase the effectiveness.

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Soft Tissue Stretching

Once foam rolling is complete, stretching the muscles is the next step. My first go-to stretch for opening up our hips and improving our mobility prior to squatting is called the “World’s Greatest Stretch.”

This stretch has 4 parts to it. First, start by assuming a deep lunge position with your left leg forward. Squeeze your glutes and drive you hips toward the floor. This movement should cause a stretch to be felt in the front of the right hip. Second, drop your left elbow to the ground. Hold for 5 seconds. Next, use your elbow or hand to drive your left knee out to the side. Make sure to keep your foot firmly planted on the ground.  Finally, rotate the entire upper body up and to the left, ending with the left arm in the air. This last movement helps address the mobility of the thoracic (mid-spine) that is also prone to stiffness.

Another stretch I like to use is the ½ kneeling hip flexor stretch. This is a great tool for addressing the muscles in the front of our hip. The hip flexors and/or quads can become excessively tight as an adaptation to sitting all day. In this video, physical therapist Mike Reinold demonstrates how to perform this stretch.


The last stretch I want to share with you today is a more position-specific movement and therefore has good carryover to the squat itself. To start, drop into a deep goblet squat. This can be performed with either a kettle bell or a weighted plate. Holding a weight in front of us allows us to worry less about balance and more on the deep squat position we want to improve.

After reaching full depth, drive your knees out to the side of your feet as far as possible with your elbows. Make sure the entire time that your feet stay firmly planted on the floor in the good tri-pod position. Driving the knees out to the side with your elbows will increase the stretch felt in your hips.

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As you open your hips up in this position we can also work on activating our glutes. The glutes are the primary muscle group that drives us up and out of the bottom of the squat. While you sit in the bottom of the goblet squat, try to squeeze your glutes and drive your knees out to the side as hard as you can for a few seconds (make sure to keep your feet flat). Next, relax and allow your body to drop into the stretch again.

This specific type of stretch is called a “Contract-Relax” technique. Physical therapists and strength coaches commonly use these techniques because they are so effective in improving our mobility compared to the classic long duration stretches. After holding for ~30 seconds to a minute, stand up and take a break. I like to perform this movement 2-3 times before moving on.

Posterior Chain Activation

The inability to properly activate the posterior chain (glutes and hamstrings) during the squat is a common finding in athletes. For this reason I recommend athletes perform a quick exercise to prime these muscles after addressing their mobility issues.

The movement I want to show you today is called Unilateral Abduction. The layman term for this exercise is ‘banded lateral kicks.’ To start place an elastic band around your ankles. I like using the mini exercise bands from Perform Better. Next assume an athletic single leg stance. Once in this position, push the hips backwards and allow the chest to move forward. This small movement allows us to engage our posterior chain and remain balanced. The cue I like to use for every squat (even small ones like this) to solidify this idea is: “squat with the hips – not with the knees.”

Once we are in position, kick the non-stance leg out to the side and back in a slow and controlled manner. The distance the leg moves out to the side is not our main concern. Focus on keeping the stance leg in a stable and unwavering position during the entire exercise. This exercise not only primes the glutes for the squatting we will perform after, but will help address core and knee stability problems.

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2-3 sets of 10-15 repetitions


After you have addressed your stiff hips, its time to check and see the progress you have made. Always employ a test-retest strategy when performing mobility exercises. This allows you to see if the tools you are using are effective in addressing the change you desire.

Performing a deep bodyweight squat is a great way to assess any changes. Also attempt a deep pistol squat. Do you notice anything different? Our goal is to make a lasting change in our overall movement pattern of the squat. Mobility tools are only effective if they carry over to an exercise we’re trying to work on.

My hope for this lecture is to give you the tools necessary to address any hip stiffness problems. If you want to remain competitive or move around pain free, it is vital that you improve and maintain good hip mobility.

Until next time,


Dr. Aaron Horschig, PT, DPT, CSCS, USAW


Dr. Kevin Sonthana, PT, DPT, CSCS


The Squat Fix: Hip Mobility Pt 2


Welcome back to Squat University! Last week we introduced the hip as a naturally stable joint that could benefit from more mobility. When we squat, mobile hips allow us to reach to full depth. Having full hip motion allows us to produce a tremendous amount of power.

With adequate mobility at the hips, our knees and lower back remain stable. The main idea behind the “Joint-By-Joint” concept is that our bodies consist of ever-connecting parts. A weak link in our chain of movement will cause a breakdown in the entire system. Stiff hips limit our ability to squat with good technique.

A test was introduced last week as a tool to uncover missing hip movement. What I want to do today is discuss the results of the Thomas test. If you didn’t test your hip mobility yet, take a minute and check out last weeks lecture.

After performing the test, what did you notice? Did you pass? Don’t worry if you failed! It is important to understand the different reasons for developing stiffness at the hips so that we can appropriately treat the problem. There is no ‘one size fits all’ approach to fixing stiff hips.

Stiff hips are primarily caused by two different factors

  • Joint Restriction
  • Soft Tissue Restrictions

Joint Restriction

Joint restriction is simply defined as a loss of space between the bones that connect at the hip. Essentially they stop moving appropriately over one another. This tightness creates a roadblock in the joint. This bony blockade halts the forward movement of the femur (thigh bone) in the hip joint when we try to bring our knee to our chest (like in the Thomas test). This movement restriction is called FAI or femoroacetabular impingement (1). This mobility problem is usually the result of repetitive strain, such as the wear and tear effects of pushing through pinching pain in the bottom of a squat. It can also be caused by long-term adaptation to a sedentary lifestyle.

If you had difficulty pulling your knee up to your chest and felt a “pinch” in the hip, there is a possibility that you have FAI. We previously discussed the analogy about the roundabout in a restricted ankle joint. With FAI, the femur will actually hit a “blockade” causing that pinching sensation in the front of the hip.


Our bodies however are a little smarter than we think and will naturally compensate our movement pattern in order to get the job done. As a result of the hip restriction, the low back is forced to move! This low back movement decreases our stability during squats, preventing optimal power and strength gains.


We can go about resolving this problem through two methods. First we can use joint mobilization exercises to increase space in the hip joint. Second we will ensure our posterior chain (glute and hamstring muscles) is working efficiently. An inability to properly activate the glutes during movements like the squat is commonly seen. We will discuss how to mobilize the hip joint and how to fire the posterior chain in net week’s lecture.

Soft Tissue Restriction

Soft tissue restrictions at the hip joint include muscles (iliopsoas and quadriceps), the IT band and fascia. These structures can become stiff and inflexible over time. For example, a sedentary lifestyle such as sitting for long periods will often lead to stiffness and tightness. Excessive inactivity can cause fascia to loose its elasticity thereby making it difficult for surrounding tissues to glide easily over one another. Plain and simple, excessive sitting decreases our natural hip flexibility and degrades normal movement patterns (such as the squat).

This type of limitation will usually be felt as tightness in the front or lateral part of the free hip during the Thomas test (refer to bottom of page). Some common findings during the Thomas test are: the free leg remains off the bed, falls out to the side, or your knee is unable to relax into a bent position. If this is the case for you, we will go about addressing these types of restrictions with two different tools – stretching and foam rolling.

Hip mobility is a very important aspect in achieving a full depth squat. Stiff hips decrease our ability to properly activate the appropriate muscles in our hips. Essentially, we bleed out a good amount of power during heavy squats. Understanding the cause of our restricted hip mobility is the first step in establishing effective ways to fix the problem. Join us next week as we address different methods for improving our stiff hips!

Until next time,

Dr. Aaron Horschig


Dr. Kevin Sonthana



1) Leunig M, Beaule PE & Ganz R. The concept of femoroacetabular impingement: current status and future perspectives. Cin Orthop Relat Res. 2009 Mar; 467(3): 616-622

The Squat Fix: Hip Mobility Pt 1

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For the past few weeks, we have discussed in detail on how the mobile ankle is crucial for the perfect squat technique. Today, we’re going to skip the knees for now and move onto the hips. This is another area of the body that tends to develop stiffness. A sedentary lifestyle and excessive sitting are a couple reasons for why we develop stiff hips. Limited range-of-motion at the hips can limit our ability to squat to full depth. Most of us could benefit from working on our hip mobility issues.

When the hips lack adequate mobility a few things can happen. First the knees will lose stability and start to bow inward. Second, the lower back will fail to remain stable and collapse into a rounded position. Each of these movement problems wreaks havoc on our power and increases our risk for injury.

Adequate hip flexion and hip internal rotation is needed to reach a full depth squat (hips below parallel). You can measure flexion of the hip by drawing a line with the torso and another line with the outside of the upper leg. The smaller or more closed the angle is, the more hip flexion the athlete has. Internal rotation is a little harder to judge on your own and will be a topic of a later lecture.


If you are unable to squat to full depth with toes relatively straightforward, hip mobility is likely a limiting factor. Today I want to introduce one of my favorite tools for assessing hip mobility. It is called the Thomas test (1).

This test is performed while lying on your back. The Thomas test’s main purpose is to look for either Iliopsoas (hip flexor muscle), Rectus Femoris (quad muscle) or Iliotibial band tightness. All of these soft tissue structure can contribute to hip mobility issues.

Start by standing next to a bed or a bench. Your hips should be in contact with the edge. Grab one of your knees and pull it towards your chest as you gently fall backwards. The knee you grab should be pulled as close to your chest as possible. As you lie on your back while holding onto your knee, allow your other leg to relax completely.

What position does your body end up? Having a friend help you with this screen is extremely beneficial. Once you screen one leg, perform the same movement on the opposite leg and see what you find.


Did you have checks in every box of the ‘pass’ column? If so you show adequate hip flexion mobility. However if you had any checks in the ‘fail’ column for this screen, you have a hip mobility restriction.

If you were unable to pull your knee fully to your chest, we are dealing with a possible hip flexion mobility issue. This could be caused by a number of factors including tight or restricted soft tissues, or even hip capsule restrictions.

If you were unable to pull one of your legs as far towards your chest as the other, you have a possible asymmetry in hip mobility. This is a red flag. Asymmetries are very important to take care of as they can negatively influence barbell squats. Often these small side-to-side differences go undiagnosed. Left untreated, asymmetries can lead to over-use injuries.

The Thomas test also allows us to screen for mobility restrictions in the opposite hip. An inability to keep your opposite leg flat on the bed and in a straight line can also point towards hip stiffness. These types of restrictions can often be due to soft tissue tightness and will be a part of the discussion in next weeks lecture.

Next week we will learn how to decipher between soft tissue issues and joint mobility issues of our hips. In addition, we will talk about a few ways to improve hip mobility with the goal of improving our squats.

Always assess movement first. If you found a problem in your single or double leg squat, we can then use different tools (like the Thomas test) to find out the cause of the breakdown the movement.

Until next time,

Dr. Aaron Horschig


Dr. Kevin Sonthana



1) Harvey D. Assessment of the flexibility of elite athletes using the modified Thomas test. Br J Sports Med 1998 32: 68-70.