Squat Science

The squat, a movement that most believe is a fundamental pattern to humans; a movement that we should strive to train and maintain for performance and just general wellness.

It is also a topic of much debate when it comes to HOW to perform a squat...

• What stance?
• What width?
• What toe angle?
• What bar position?
• What variation?
• How deep?

I've worked with close to a thousand athletes and guess what… they all squat differently.  Different stance widths,  different foot positions, different depths, different variation preferences, different bar positions, etc.  

I'm tired of hearing athletes being told they MUST squat a certain way or there is only ONE way to squat… that is rubbish and certainly isn't rooted in science. 

Let's think about this - do you really think someone 6'6 should squat the same as someone 5'2?  Should someone with long femurs and a short torso squat the same as someone with short femurs and a long torso?  Should someone with retroverted hips squat the same as someone with anteverted hips?

If I have a group of 20 athletes and had them all squat with a stance of their preference, to a depth they felt comfortable, with a toe angle that allows the most freedom - you know what I'd find?  20 different squats with different widths, foot angles, depths, trunk angles, etc.  

So why do coaches, PT's still try to jam a square peg into a round hole by thinking there is only one way for people to squat?  You NEED to squat with toes forward, in a shoulder-width stance, to a parallel depth!

Now I'm a man of science, not just anecdotal evidence, so let's see what some of the literature on anatomy and skeletal structure of the hips says and how this may effect the squat

• The femoral neck/head isn't the same in every person.  Zalawadia et al (2010) demonstrated that as much as 24-degrees difference in anteversion and retroversion is common.  Zalawadia also noted that these differences of anteversion and retroversion can differ from side to side - not all hips are symmetrical!  

With sooo much potential variation is peoples hips, not to mention potential side to side difference in the same person - you still think everybody's squat should look EXACTLY the same?  Femoral and acetabulum structure will play the main role in ones ability to squat in certain positions to certain depths - NOT a universal preference made up by some person. 

• Laborie et al (2012) noted that anteversion and retroversion isn't strictly contained to the femoral head, it can also be present in the acetabulum.  They looked at  over 2000 samples of centre-edge angles of the acetabulum  and found angles differed from 20.8-45 degrees

Again, how can we expect someone with a 20.8-degree anteversion to squat the same as someone with a 45-degree retroversion?

• Knutson (2005) looked at leg length, and found that about 90% people have a discrepancy with the average difference of about half a centimeter.
• Flanagan  & Salem (2007) examined different kinetic variables in the squat of 18 experienced lifters. They looked at many things including average joint moments at the hip/knee/ankle, ground reaction forces in each foot, center of pressure for each foot, and maximum flexion angle at the knee/hip/ankle. They found many things (some statistically significant, others not) including side to side differences in center of pressure, ground reaction forces, and joint moments at the ankle, knee, and hip (especially the hip). The researchers concluded that NOBODY was balanced and every subject demonstrated differences in at least on of the joints (ankle, knee, hip)

It is COMMON that people squat with asymmetries and differences from side to side.  It's normal to have someone feel and perform better with one toe angled out/in, staggered forward/backward,   externally/internally rotated compared to the other.

If pain isn't present - THERE IS NOTHING WRONG WITH THIS - and it's likely aiding in performance, comfort, and health.  We aren't symmetrical beings and sometimes forcing symmetry may actually be taking someone out of their "neutral".  

Want to see what these differences actually look like?  Check out the below photos and see how these skeletal structures can differ and visualize how they'll dictate an athletes optimal squat.

If we tried to take these people and squat them in a toes forward, shoulder width stance, to parallel, what do you think would happen?

Some would ace the test, while others would fail miserably… why?

Much of it would have to do with this structure - NOT some mobility, stability, strength, motor control dysfunction, but rather something they CANNOT change - their bone structure.

We seem to be in a stage where we see someone whose can't squat deep, or prefers a wide stance, or turns their feet turn out, or has butt wink and we jump all over them with how their "insert joint/muscle" is tight/weak and needs soft-tissue, mobility, or activation work, BUT in many situations, no matter what correctives, or soft-tissue, or crazy mobility you throw at the athlete - they just won't be able to squat in certain positions.

Let's wet our whistle with a little bit more literature

• Elson and Aspinal (2008) showed what is tremendously obvious for coaches that actually work with people - there are vast differences in range of motion in hip flexion and extension - meaning some people are just better suited for deep hip flexion (deep squat), while this position would cause massive problems for others. 
• D'Lima et al (200) demonstrated that differences in femoral neck/head thickness (as little as 2mm) could impact hip flexor ROM by 1.5-8.5 degrees.  
• Lamontagne et al (2009) looked at people with femoroacetabular impingement syndrome (FAI) and squat ability and concluded due to anatomical variations at the hip such as cam or pincer, there are plenty of lifters who will never be able to deep squat with proper form.

So should everybody squat to parallel or ass to grass?  Should everybody have the same stance width and toe angle?

NO!!!

Some have a tendency to squat deep, while others have tendency for hip extension.  If we force them to parallel or ass to grass we may be forcing bone on bone or a hip impingement - not good things.   The only people that NEED to squat to parallel are powerlfiters, it's a requirement of their sport.  As for athletes, there is no rule book that says you have to squat to parallel or beyond - it's not a requirement nor is it going to make or break performance.

Again, ones ability to squat to different depths in different stances can be explained by their skeletal structure - NOT necessarily mobility or soft tissue or strength issues.  It also means trying to say everybody should squat the SAME WAY is a terrible thought process and could actually be causing more harm than good.

Here's a quote from the great Stu McGill, considered the World's foremost expert on spinal health - "The most important matter on all of this is the depth of the hip socket. If people are looking up on the internet, depth of the hip socket and squat ability, they won’t find it. They have to go to the hip dysplasia literature. What they’ll find is that there are groups in the world with very shallow hip sockets (allow greater hip flexion) and some with deep hip sockets (make it difficult for deep hip flexion)."

Even the World's expert says it's structure that dictates deep squat ability, it's NOT some universal standard.

​Insert pictures of strong peeps, lifting heavy things and what do you see?

No identical stance, depth, toe angle, etc. 

​Why again do we try to force people to squat a certain way, to a certain depth?  Coach athletes as individuals. 

Let's look at some more myths that pertain to squatting

Knee's Can't Go Beyond The Toes

Here is another myth is purported in all areas and there’s little evidence to support this claim. The knees passing beyond the toes is not some universal point where all of a sudden the stresses on the knee become dangerous and every point before that is safe. 

You know what's even more?  Artificially restricting or trying to prevent forward movement of the knees may be detrimental to the hips and back. Fry et al (2003) looked at the effect of restricted squats where a wooden board was placed in front of the lifter that didn't allow the knees to track past the toes.  

​What did they find?  

Restricted Squat

As expected, the board restricted setting reduced torque on the knees, but increased torque at the hip and low back.  So you take stress on one joint, only to increase it at another - so pick your poison.  
The researchers concluded, "Exercise technique guidelines should not be based primarily on force characteristics for only one involved joint (e.g., knees) while ignoring other anatomical areas (e.g., hips and low back).”  

Artificially or cueing an athlete to change their natural mechanics may effect the joint being cued, but those forces and torque need to go somewhere.   

While shear forces have been shown to increase in the deep squat position with forward knees, the body can handle them appropriately without risk for injury (Schoenfeld (2010)).   The most thorough review of squat depth on knee pain showed the demands on these tissues in a deep squat are well below the maximum that those tissues can withstand (Hartmann et al (2013)).  THEY AREN'T DANGEROUS!
​
Plus, every Olympic lifter of all-time, theoretically should have messed up knees and some PT would tell them they're lifting wrong…

Squat Stance and Squat Variation

Guess what - the type of squat you use isn't vastly different from each other.  EMG between a front squat and back squat aren't that different and some studies even showing NO STATISTICAL DIFFERENCE in muscle activities between front and back squats.  (Contreras et al (2016); Gullet et al (2009)).  In general, the front squat will lead to slightly more quad activation and thoracic extension strength; while back squat slightly more glute/hamstring activation, but again, the EMG difference between the two isn't likely a good reason for choosing one over the other.

How about wide stance vs narrow stance?

Wide stance squats tends to activate greater adductor and glute compared to narrow squat, with no difference between quad activation (Escamilla et al. (2001); Paoli et al (2009); Steven & Donald (1999)).  Swinton et al (2012) recently demonstrated exactly this as the researchers showed EMG results for glute activation were significantly higher in a wide stance compared to a narrow stance.  These EMG results also showed that quadricep activation between the stances were identical - concluding, muscle activation wise, a narrow stance isn't superior to a wide stance.

How about toe angle or hip angle?

Ninos et al. (1997) found no difference in vastus medialis activation between barbell back squats with two different hip rotation angles (feet pointing outwards vs. feet pointing forwards).  While, Pereira et al (2010) found externally rotating the hip to 30 and 50-degrees resulted in greater hip adductor activation with no change in rectus femoris activation, leading the researchers to conclude that squatting to 60-90 degrees of knee flexion with 30 degrees of external rotation maximized muscle activation.

Again, there is NO LITERATURE supporting the NEED to squat with toes forward! Rather than squatting with your toes forward or pointed out to a predetermined degree and forcing your knees and hips to follow along, you’re better off seeing what hip and knee position feels the strongest and most comfortable, and letting that determine how far out you point your feet (Nuckols (2016))

In a great review of all the variables that effect muscle activation of a loaded back squat, Clark et al (2012) concluded, research of common variations such as stance width, hip rotation, and front squat do not significantly affect muscle activation.  Turning the toes out, however, only changes the activation of the adductor muscle group. The glutes and quads (the main movers in the squat) are not significantly activated to a greater extent by any of the variables (Clark at el (2012)).

So we've seen, specific squat variations - wide, narrow, toes forward, toes out, depth - aren't make a break factors when it comes to muscle activation, joint stress, or performance.

So again, why would be ever think there is only one way to squat and what would make this way superior?  The fact is, there isn't a single strategy to squat and instead should be dictated upon by the individuals unique skeletal structure, limb lengths, past injury history, mobility/stability factors, and biomechanics.

Here's just a small list of things that influence squat mechanics 

• Foot Wear (elevated heel vs flat heel)
• Long Tibia vs Short Femur
• Short Tibia vs Long Femur
• Short Femur vs Long Torso
• Long Femur vs Short Torso
• Body Mass
• Stance Width
• Toe Angle
• Foot Size (Length)
• Cueing
• Anterior vs Posterior Chain Strength
• Specific Joint Mobility and Stability Strengths and Weaknesses
• Bar Position

Linked below is a really cool that demonstrates how different body part lengths, stance width, bar positioning, etc effect the outcome of a squat will look like - again it's basic biomechanics - http://mysquatmechanics.com

Here are some pictures of how simply changing levers, stance width, ankle mobility, and bar position effect the end look of a squat

All-In-All

The goal of this article is to demonstrate there is no universal way to squat and we need to work to allow and find our athletes optimal way to squat based on their individual anatomy, levers, mobility/stability needs, past injury history, etc - and NOT try to pigeon-hole everybody into a certain way of squatting.

Please share this with anybody you think would benefit and let's stop the squat stupidity from spreading. 

 PS - Below are some squat assessment videos on what we might use to assess our athletes to find their best squatting stance. 














References:

 Clark, D. R., Lambert, M. I., & Hunter, A. M. (2012). Muscle activation in the loaded free barbell squat: a brief review. The Journal of Strength & Conditioning Research, 26(4), 1169-1178.

Contreras, B., Vigotsky, A. D., Schoenfeld, B. J., Beardsley, C., & Cronin, J. (2016). A comparison of gluteus maximus, biceps femoris, and vastus lateralis electromyography amplitude in the parallel, full, and front squat variations in resistance-trained females. Journal of applied biomechanics, 32(1), 16-22.

Escamilla, R. F., Fleisig, G. S., Lowry, T. M., Barrentine, S. W., & Andrews, J. R. (2001). A three-dimensional biomechanical analysis of the squat during varying stance widths. Medicine and science in sports and exercise, 33(6), 984-998.

Flanagan, S. P., & Salem, G. J. (2007). BILATERAL DIFFERENCES IN THE NET JOINT TORQUES DURING THE SQUAT EXERCIS. The Journal of Strength & Conditioning Research, 21(4), 1220-1226.

Gullett, J. C., Tillman, M. D., Gutierrez, G. M., & Chow, J. W. (2009). A biomechanical comparison of back and front squats in healthy trained individuals. The Journal of Strength & Conditioning Research, 23(1), 284-292.

Hartmann, H., Wirth, K., & Klusemann, M. (2013). Analysis of the load on the knee joint and vertebral column with changes in squatting depth and weight load. Sports medicine, 43(10), 993-1008.

Knutson, G. A. (2005). Anatomic and functional leg-length inequality: a review and recommendation for clinical decision-making. Part I, anatomic leg-length inequality: prevalence, magnitude, effects and clinical significance. Chiropractic & osteopathy, 13(1), 1.

Lamontagne, M., Kennedy, M. J., & Beaulé, P. E. (2009). The effect of cam FAI on hip and pelvic motion during maximum squat. Clinical orthopaedics and related research, 467(3), 645-650.

Ninos, J. C., Irrgang, J. J., Burdett, R., & Weiss, J. R. (1997). Electromyographic analysis of the squat performed in self-selected lower extremity neutral rotation and 30 of lower extremity turn-out from the self-selected neutral position. Journal of Orthopaedic & Sports Physical Therapy, 25(5), 307-315.

Nuckols, Greg.  http://strengtheory.com/how-to-squat/. 2016

Paoli, A., Marcolin, G., & Petrone, N. (2009). The effect of stance width on the electromyographical activity of eight superficial thigh muscles during back squat with different bar loads. The Journal of Strength & Conditioning Research, 23(1), 246-250.

Pereira, G. R., Leporace, G., das Virgens Chagas, D., Furtado, L. F., Praxedes, J., & Batista, L. A. (2010). Influence of hip external rotation on hip adductor and rectus femoris myoelectric activity during a dynamic parallel squat. The Journal of Strength & Conditioning Research, 24(10), 2749-2754.

Schoenfeld, B. J. (2010). Squatting kinematics and kinetics and their application to exercise performance. The Journal of Strength & Conditioning Research, 24(12), 3497-3506.

Steven, T. M., & Donald, R. M. (1999). Stance width and bar load effects on leg muscle activity during the parallel squat. Med Sci Sports Exerc, 31, 428-436.

Swinton PA, et al (2012) A Biomechanical Comparison of the Traditional Squat, Powerlifting Squat, and Box Squat. The Journal of Strength & Conditioning Research 26(7):1805–16​​

The False Reality of the FMS

The Functional Movement Screen (FMS) is a popular screen used by coaches and sports medicine professionals as a screen for movement competency.  It is composed of 7 movements and scored on a 0-3 scale, where 0 = pain, 1 = couldn't perform the task, 2 = performed task with compensation, 3 = performed task correctly.

The scores from the 7 movements are combined into a final score out of 21.  The score is supposed to predict injury and performance and it is even suggested that scores under 14 predict a greater risk of injury.

The FMS claims to identify compensatory movement patterns that are indicative of increased injury risk and inefficient movement that causes reduced performance.

That's a pretty big claim and one the FMS has NOT lived up to.  

First and foremost, the FMS is supposed to be a SCREEN and unfortunately practitioners far out-reach the boundaries of a screen when applying the FMS.  The FMS places labels on people and their movement and with anything that places labels, we certainly hope there is some strong evidence that supports these labels.

This is tremendously important because when someone scores poorly on a test, they get told their chance of getting injured is high and their performance is decreased. This only implants fear and guarding in the client, rather than confidence and overall is a great way to build fear of movement and sport.  Coaches and those in sports medicine NEED to get beyond telling clients that because they score poorly on a test, they'll get injured - this isn't beneficial to anyone.

Again, the FMS is supposed to be used as a screen, NOT a diagnostic tool… it doesn't and should NOT be used to diagnose things.  Yet, I hear people all over, use the FMS to diagnose supposed dysfunction.

It is a baseline screen, and honestly only scratches the surface of what else needs to be assessed. I have heard of athletes who performed the FMS on them, and then get told rash diagnoses and/or put fear in the athlete basically saying that it's a miracle they can even make it through a day of school with all the dysfunction's they have.

"You shouldn't squat based on your OH Squat assessment; 

your core is sooo weak; you have tight hamstrings - you shouldn't sprint; 

you have an asymmetrical rotary stability score - you will get injured if you don't improve it"

Given all radical leaps in faith the FMS asserts, let's take a closer look at various aspects of the FMS and their claims

The FMS claims to identify compensatory movement patterns that are indicative of increased injury risk and inefficient movement that causes reduced performance.

This is the big one I'll address because it claims an awful lot, and as you'll see, without much scientific support.

In order for the FMS, or any screen for that matter, to be a valid indicator of injury or inefficient movement in sport, it is logical that the compensatory movement patterns that are tested during the screen must be the same or similar to those that are performed in sport - which the FMS does not (Beardsley)

• Dossa et al. (2014) studied junior level hockey players to see if the FMS could predict injuries throughout a season.  The researchers concluded the FMS could NOT be recommended as a screening tool for injury prevention.

• McCall et al. (2015) reviewed the scientific level of evidence of three of the most commonly-reported risk factors, screens, and injury prevention exercises in a previously published survey of 44 premier league soccer teams. The FMS was one of the identified screens. They assigned the FMS a grade D, where D = insufficient evidence to assign a specific recommendation.  

• Parchmann et al. (2011) studied the FMS to evaluate whether it was related to sport performance and found there were NO significant correlations between the higher FMS scores and on-field sports performance.

• Even the founders of the FMS did a literature review on the FMS and stated “the use of a total FMS score for predicting injury risk should be avoided, as the individual components of the test are not correlated with one another and are therefore not measuring the same underlying variable" (Cook et al. (2014)).

• Several researchers have assessed FMS scores on athletes of different ability levels to see if higher performing athletes scored higher on the FMS compared to lower level athletes.  They found there to be no difference between FMS scores and the level of the athlete.  This shows that the FMS does not and cannot predict performance. (Fox et al. 2013; Grygorowicz et al. 2013; & Loudon et al. 2014). 

• Lockie et al. (2015) found very little correlation between FMS scores and multidirectional speed and jumping tests in healthy male subjects. 

• In addition, many investigations have been performed to assess the correlations between sprinting, jumping, throwing and agility performances and FMS scores and most have found no relationship between any measure of athletic performance and FMS score (Okada et al. 2011; Parchman et al. 2011; Lockie et al. 2015b).

• When it comes to predicting injury, Dallinga et al. (2012) reviewed the literature in respect of the tests that could predict a greater risk of injury.  They reported that general joint laxity, the Star Excursion Balance test, age, a lower hamstring-to-quadriceps strength ratio, and a reduced hip abduction range of motion could all predict a higher risk of lower body injuries.                        To test an aspect of this injury prediction model, Paszkewicz et al. (2013) investigated the association between total FMS score and Beighton and Horan joint mobility index (BHJMI) in adolescent athletes. They found no correlation between total FMS score and BHJMI index.  We also know the FMS can't target any of the other aspects shown by Dallinga et al. (2012) as being predictive of injury. 

• A major flaw with the FMS is it's ability or lack of ability to distinguish between athletes. Shouldn't we assess individual variances between athletes in different sports?  A baseball player should definitely be assessed differently than a cross country runner or an offensive lineman in football.  Each one of these athletes will exhibit markedly different mechanical adaptations based on the demands of their sport and position.  Whose to say these adaptations are wrong or bad?  "Faulty" movement patterns do not always lead to pain or injury and in many cases these adaptations are what make athletes better performers in their sport.  Guess what, tissues positively adapt and get stronger based on the stresses placed on them… this is why a pitcher's arm will be very different from others - and this IS NOT a bad thing.  Poor posture does not mean its pathological nor does it mean that person will suffer from more musculoskeletal problems.  So can we please STOP TELLING ATHLETES THIS

The FMS Can Predict Injury

Short answer - NO IT DOESN'T

• Schneiders et al. (2011) looked to find normative values in the FMS with young athletes.  They evaluated the FMS based on the assumption that identifiable biomechanical deficits in fundamental movement patterns have the potential to limit performance and render the athlete susceptible to injury.  In this study, the researchers found that healthy individuals and previously injured individuals had the same scores.  So the FMS could not even detect differences in injured individuals compared to healthy ones.  This is of concern as past injury is a main risk factor of future injury. If FMS cannot detect any sign of recent injuries, it seems unlikely that it can detect future risk, let alone be used as a basis for a specific therapy.

• Frost et al. (2013) questioned the ability of the FMS to assess dysfunction. They looked at 21 firefighters who initially performed a standard screen followed by a repeat screen 5 minutes later, but on the 2nd trial participants were given a verbal description of the grading criteria before performing each test. All firefighters improved their scores within minutes of being told what movement patterns were required - The average score improved from 14.1 ± 1.8 to 16.7 ± 1.9 points; remember in just 5-MINUTES.  Therefore, changes in FMS score may not be due to actual improvements in mechanical efficiency such as mobility, stability or coordination of an athlete but rather simply a knowledge of what the task requires.   This isn't the first time this outcome has been shown, as there are indications that subjects may deliberately alter their movement patterns during the FMS test in order to score higher (Teyhen (2012); Schultz (2013)).  This is supposed to be a reliable screen?

• To piggyback the last bullet point - The FMS sum score appears to be very reliable between raters (inter-rater) and within raters for a video of the same test (intra-rater). However as we just discussed, test-retest is less reliable, indicating that the same subjects may score differently on different occasions, despite there being no biomechanical changes made (Beardsley).

• Okada et al. (2011) studied the relationship between FMS scores and "core" strength on actual sport performance.  To keep beating a dead horse, it was found "core" strength and FMS scores are NOT strong predictors of sports performance… yet PT's continues to tell clients/athletes core strength and quality FMS scores are important for performance and pain.

• As I said earlier, it has been suggested that scores under 14 predict a greater risk of injury.  BUT, O'Connor et al. (2011) demonstrated that scores of 18 or more were more at risk for injury than those who scored less than 18 in 874 marine officers.  Scores above 14 are supposed to have decreased risk of injury, not the opposite, especially with a score so close to being perfect. 

These 7 Tests Predict Global Movement?

At the end of the day, it is a far stretch to think these 7 tests somehow can predict an athletes global movement, especially when the athlete is under load, speed, chaos, and fatigue.

Yet, some believe that these slow, safe, pre-planned, mostly static tests will predict dynamic movement.   It's one thing to do tests in a very controlled, passive type of environment compared to dynamic. I've seen a lot of good things in table assessments or FMS type screens, only to go to HELL under speed or load… Let this be clear, while these screens can have some benefit, they tend to have absolutely NO transfer to dynamic, reactive, and chaotic environments such as sport.

For example, what do we gain from the Overhead Squat (OHS)?

Let's be real here, using the OHS as an assessment of general movement ability, is like using a tennis serve to test coordination (Quote from Dr. Cobb of Z-Health).  The OHS is arguably the most complex version of a squat.  So instead of starting with a baseline test and a more basic squat version, we skip A-Y and go straight to Z. In addition, squatting while reaching overhead is not something that humans are designed to do. It is a skill, and anybody, the first time you ask them to perform something that is completely new to them will struggle.  Chances are, the faults you find in the OHS are due to a lack of performing this specific task as opposed to a lack of good general movement patterns.

Also, why are no other squat assessments used, such as adding a counter-weight (clarify mobility vs stability needs), taking a wide stance, letting toes track outward, using an asymmetrical stance, etc.

Nope, instead the FMS forces everybody to take a shoulder width stance with toes forward and discounts the fact that everybody's hip anatomy is different and to say that you need to be able to OHS with a shoulder-width stance, with toes forward is absurd… how are still on this? Take a look at the pictures below and tell me if these people should be judged on the same squatting scale given their vastly different anatomical structures.

It's like trying to fit a square peg into a round whole when we say you should be able to squat in this stance - to this depth and apply it to the whole population.

In Closing

This isn't to say that the FMS is useless, but let's be real, anybody with a grasp of anatomy and biomechanics can clearly see the gaps in reasoning in using solely the FMS as an assessment tool.

Now, the FMS and those who use it, do a wonderful job of marketing and "scaring" athletes/clients into thinking that because they scored poorly, they need additional training.  I mean, it's a beautiful system in a business sense, although as I've shown, it lacks support from research to do what it claims to do.

So a word of caution to athletes/clients/parents - usually those promoting the FMS have something to sell.  They'll show you where you're "lacking" and probably have some program that will "fix" these problems.

A word to coaches and professionals - come up with your own assessment that is based in science and evaluates the athlete not only statically, but dynamically and in a manner that is the same or similar to those that are performed in sport.  Also, please use tremendous caution when telling athletes/clients they are "broken" or dysfunctional or on their way to injury.  This is bad business and psychologically damaging to the athlete/client and only creates fear of movement.


Check out our Elite Performance Podcast for a little breakdown of what goes into our assessment process (Starting at 4:00-14:00min)




Go Get 'Em!


References:

       Beardsley - https://www.strengthandconditioningresearch.com/functional-movement-screen-fms/#CONT

       Cook, G., Burton, L., Hoogenboom, B. J., & Voight, M. (2014). Functional movement screening: the use of fundamental movements as an assessment of function-part 2. International journal of sports physical therapy, 9(4), 549-563
     
       Dallinga, J. M., Benjaminse, A., & Lemmink, K. A. (2012). Which Screening Tools Can Predict Injury to the Lower Extremities in Team Sports?. Sports medicine, 42(9), 791-815

       Dossa, K., Cashman, G., Howitt, S., West, B., & Murray, N. (2014). Can injury in major junior hockey players be predicted by a pre-season functional movement screen–a prospective cohort study. The Journal of the Canadian Chiropractic Association, 58(4), 421.

       Fox, D., O’Malley, E., & Blake, C. (2014). Normative Data for the Functional Movement Screen™ in Male Gaelic Field Sports. Physical Therapy in Sport.

       Frost, D. M., Beach, T. A., Callaghan, J. P., & McGill, S. M. (2013b). FMS™ scores change with performers’ knowledge of the grading criteria-Are general whole-body movement screens capturing” dysfunction”? The Journal of Strength & Conditioning Research.
       

       Grygorowicz, M., Piontek, T., & Dudzinski, W. (2013). Evaluation of Functional Limitations in Female Soccer Players and Their Relationship with Sports Level–A Cross Sectional Study. PloS one, 8(6), e66871

   
       Lederman E. The Myth of Core Stability. Journal of Bodyworks Movement Therapy. 2010 Jan;14(1):84–98.       

       Lockie, R. G., Schultz, A. B., Jordan, C. A., Callaghan, S. J., Jeffriess, M. D., & Luczo, T. M. (2015). Can selected functional movement screen assessments be used to identify movement deficiencies that could affect multidirectional speed and jump performance?. The Journal of Strength & Conditioning Research, 29(1), 195-205

       Loudon, J. K., Parkerson-Mitchell, A. J., Hildebrand, L. D., & Teague, C. (2014). Functional movement screen scores in a group of running athletes. The Journal of Strength & Conditioning Research, 28(4), 909-913

       McCall, A., Carling, C., Davison, M., Nedelec, M., Le Gall, F., Berthoin, S., & Dupont, G. (2015). Injury risk factors, screening tests and preventative strategies: a systematic review of the evidence that underpins the perceptions and practices of 44 football (soccer) teams from various premier leagues. British journal of sports medicine.

       Okada, T., Huxel, K. C., & Nesser, T. W. (2011). Relationship between core stability, functional movement, and performance. The Journal of Strength & Conditioning Research, 25(1), 252-261
    
       O’Connor, F. G., Deuster, P. A., Davis, J., Pappas, C. G., & Knapik, J. J. (2011). Functional movement screening: predicting injuries in officer candidates. Med Sci Sports Exerc, 43(12), 2224-30.

       Parchmann, C. J., & McBride, J. M. (2011). Relationship between functional movement screen and athletic performance. The Journal of Strength & Conditioning Research, 25(12), 3378-3384.
  
       Paszkewicz, J. R., & Cailee Welch McCarty, D. (2013). Comparison of Functional and Static Evaluation Tools Among Adolescent Athletes. The Journal of Strength & Conditioning Research.

       Schneiders, A. G., Davidsson, Å., Hörman, E. & Sullivan, S. J. (2011). Functional movement screenTM normative values in a young, active population. International Journal of Sports Physical Therapy, 6(2),75.

        Shultz, R., Anderson, S. C., Matheson, G. O., Marcello, B., & Besier, T. (2013). Test-Retest and Interrater Reliability of the Functional Movement Screen. Journal of athletic training, 48(3), 331-336

       Teyhen, D. S., Shaffer, S. W., Lorenson, C. L., Halfpap, J. P., Donofry, D. F., Walker, M. J., & Childs, J. D. (2012). The Functional Movement Screen: a reliability study. The Journal of Orthopaedic and Sports Physical Therapy, 42(6), 530-40

       Unsgaard-Tøndel M, Fladmark AM, Salvesen O, Vasseljen O. Motor Control Exercises, Sling Exercises, and General Exercises for Patients With Chronic Low Back Pain: A Randomized Controlled Trial With 1-Year Follow-up. Phys Ther. 2010 Jul.

Anatomy Lesson: The Shoulder/ Scapula

A wise man once said, "If you're feeling like a pimp, go and brush your shoulders off." 

Well I'm definitely feeling like a pimp, so I'm gonna go ahead and talk about the shoulder, because there isn't anything more sexy than shoulders.  Or if your like me the soldiers; I suck at pronouncing the difference between the two - I can't be the only one.

We've gotten good response from our anatomy lesson series, so let's get one step further and put the shoulder under the microscope.  If you've missed any of the other lessons, check them out

Ankle/Foot
Knee
Hip/Pelvis
Spine

The shoulder is a real interesting joint, it's very similar to the hip except without the amount of muscle mass and stability.  The shoulder needs a tremendous amount of mobility and stability - just think about throwing a baseball.  In fact during an overhead throw the shoulder goes through 7,000 - 9,000 degrees of rotation per second, that's the fastest motion the human body produces.  The shoulder goes through crazy ranges of motion and bears the brunt of extreme forces and stresses.  It is a truly incredible joint considering all it does and the unique actions it is involved in.  It's like the J-Timberlake of the body - J-Timberlake rocks the music, acting, dancing, and comedy world; while the shoulder rocks the mobility, stability, and modeling world.

The Shoulder

Bones

   - Humerus - Upper Arm
   - Clavicle - Collar Bone
   - Scapula - Shoulder Blade

While the shoulder is often thought of as a singular joint or location it's not.  Four different joints are actually connected or related to the shoulder

   - Glenhumeral Joint - This is the traditional shoulder joint, where the humerus fits into the socket of the scapula.
   - Acromioclavicular (AC) Joint - This is where the clavicle meets the acromion on the scapula.
   - Sternoclavicular (SC) Joint - This is where the clavicle connects to the sternum.
   - Scapulothroacic Joint - This is called a false joint because it's not really a true joint, it's a location where the scapula glides against the rib cage.  It's important to mention because the surrounding muscles work to keep the scapula lined up during shoulder movements.

Ligaments - Remember ligaments are soft tissue structures that connect bones to bone, are a main source of stability for the shoulder.  Here's a quick run down of important ligaments in the shoulder

 - Acromioclavicular
 - Coracoclavicular
 - Sternoclavicular
 - Interclavicular
 - Costoclavicular
 - Coracoacromial
 - Coracohumeral
 - Glenohumeral

Muscles and Actions - There are a ton of muscles that impact the function and movement of the shoulder.  It's really a busy area in terms of small, intricate muscles involved and due to the wide range of scapular, cervical, and clavicular involvement on the shoulder.

   - Deltoid - Deltoid is the traditional big shoulder muscle.  The deltoid is often broken into 3 groups: Anterior Delt, Lateral Delt, and Rear Delt.   Each distinct group is contributes more or less to certain movements, but in general the delts play a big role in abduction, rotation, flexion, and extension.

   - Rotator Cuff Complex - An easy way to remember the rotator cuff is SITS

Supraspinatus - Primary responsibility involves concentric abduction of the humerus

Infraspinatus - Primary action involves external rotation of the humerus

Teres Minor -  Primary role is external rotation of the humerus

Subscapularis - Primary action is internal rotation of the humerus.

While each specific muscle of the rotator cuff complex has a different primary function, it is key to know that they all work together it keep the humeral head centered in the glenoid fossa.  They are not primary movers, they are stabilizers and their most important job is to keep the humeral head centered.

Scapula Muscles - Assist in scapular stabilization and active movement of the scapula.

   Trapezius - Three groups of the Trapezius
       - Upper Traps - Elevation, Upward Rotation
       - Mid Traps - Retraction, Upward Rotation
       - Lower Traps - Retraction, Upward Rotation, Depression
   Levator Scapulae - Elevation, Downward Rotation
   Rhomboid Group - Retract, Elevation and Downward Rotation
   Serratus Anterior - Protraction and Upward Rotation
   Pec Minor - Downward Rotation, Depression, Retraction

Other Humeral Muscles - These help attach the humerus to the trunk
   Lats
   Pec Major
   Biceps Brachii

Problems

The shoulder joint is one of the most injured joint in the body.  According to Sipes et al, 30% of athletes suffer a shoulder injury during their career.  Overhead sports such as baseball, volleyball, QBs in football, softball, and throwers in track and field know all to well how stressful overhead movements can be on the shoulder and the importance of maintaining health in the joint.  Remember the shoulder goes through 7,000 - 9,000 degrees of rotation per second during overhead movements!

Also many lifters experience problems performing different vertical pushes and pulls ie overhead press, snatch, jerk, pull-up, etc.  A great deal of ROM, strength, and stability is need for these movements, and many lack those qualities.  Let's go ahead a take a peek at a few common problem areas.

Impingements - An impingement is basically a compression of the tendons of the rotator cuff in the glenohumeral joint, usually in the subacromial space.  It can become chronic and cause serious inflammation of the tendons and limit ROM, strength, stability, and cause pain.

First off not everybody's shoulder is created equally.  Some people have naturally poorly structured shoulder joints for overhead sports and lifts.  A big component of this is the shape of the acromion process. 

Type 1 - Flat, this shape is built for overhead actions, and the risk of impingement cuasing pain is minimal.
Type 2 - Curved, this shape needs to have some precaution to take.  Due to the curve, subacromial space is reduced and this can increase risk of impingement.
Type 3 - Beaked, sorry but people with this acromial shape are unfortunately not meant to perform overhead actions.  The subacromial space is greatly reduced and overhead movements can often lead to problems.

Shoulder impingement's are pretty dang common, most people have an impingement of some degree, but whether that impingement is painful or not depends a lot on the the shape of the acromion, soft tissue health, stability, mobility, and strength of the the shoulder joints.

Overall shoulder impingement's are a lot more advanced and in-depth than what we just explained.  There are many different factors that come into play, but that is a basic overview.  Watch Dr. Evan Osar talk a little bit more about impingement's and keeping the humeral head centered.

AC Joint - An AC injury is commonly known as a shoulder separation.  Recall the AC joint is the connection of the collar bone to the top of the shoulder (acromion).  An injury usually occurs to the AC joint after a brunt force or falling on the shoulder.  But tendonitis and tendonosis can also be common in the AC due to lots of overhead movements.  I've separated both AC joints and let me tell you they aren't fun and they can take a long time to fully heal.  Some bad AC separations require surgery, and you may recall top QB Sam Bradford and Matthew Stafford have both surgery on their AC joints.

Superior Labrum, Anterior to Posterior Tears (SLAP) - The labrum is a fibrocartilaginous tissue around the rim of the glenoid fossa and helps keep the humerus supported in the joint.  A SLAP tear refers to an injury to the labrum of the shoulder, and SLAP specifically points to the upper part of the labrum running from front to back.  These kind of tears usually occur from falling on an outstretched arm, repetitive OH movements, and from lots of throwing.  You can often tell a SLAP tear because you'll hear a clicking sound in the shoulder or during certain ranges of motion the shoulder will "catch".

Glenohumeral Internal Rotation Deficit (GIRD) - GIRD is a deficit when comparing internal rotation of the dominant shoulder to non-dominant shoulder.  The difference between the two should not exceed 15 degrees.  On the same note is measurement of total range of motion in terms of the sum of IR and ER.  Comparing dominant arm and non-dominant arm, the difference should not be more than 5 degrees.  The differences in IR and total rotation are often seen in overhead athletes.  So many repetitions of overhead movements put a lot of stress on the posterior components of the shoulder to decelerate the arm.  This causes some inflammation, gunky tissue, and those muscles and tissues to become overworked, and this tightness in the posterior shoulder decreases IR.  If someone presents more than 15 degrees of difference of IR and 5 degrees of total rotation, this increases risk of shoulder injuries.  Now if GIRD is found, don't be in a rush to go ahead and stretch into internal rotation.  There are many other factors that contribute to GIRD such as scapular mobility/stability, labrum health, capsular health, rib position, soft tissue quality, and cuff strength.

Fixes

Mobility - Let's clear the air right now, most shoulder problems result from scapular dysfunction.  The scapula doesn't get the love it deserves considering it is half of the glenohumeral joint. 
Consider this, the head of humerus should move in conjunction with scapula.  Think about a golf ball on a tee.  If you were to grab the ball and tee together and move it around, the ball would stay centered on the tee and the two would move in conjunction.  If you have an immobile scapula, then the humeral head compensates and loses centration of the glenoid fossa and this is when problems occur.  The scapula needs to be able to move freely and have full range of motion to support the movement of the humerus. 

A way to attack this is to work on thoracic spine mobility.  Remember the scapula is essentially a free floating bone with numerous muscular attachments.  Working on thoracic mobility also targets scapular mobility due to the high amounts of connection and "team-work" between the two.

Balance - Many problems at the shoulder occur to imbalances in training and everyday life.  We've talked about improving the balance between pull vs push exercises and getting that ratio more to 2:1 in favor of pulls.  But not as well known is improving the balance of upward rotation vs downward rotation. 

This imbalance can lead to scapular depression, which is very common with many athlete these days.
This imbalance leads to the shoulder blades being drawn back and down.  Take a look at your collar bone in the mirror.  It should have an upward angle going from medial to lateral.  When the downward rotators take over it pulls your shoulders down, and your collar bones will sit more flat or parallel to the ground.  Doing loads of bench, row, deads, and getting cued to death with "shoulders back and down!" leads to the downward rotators winning the balance battle of the scapula.  So it's time to give the upward rotators some love.  Target the serratus, upper traps, and lower traps (upward rotators) with face pulls, no money, overhead shrugs, and prone wall slides.

Soft Tissue Work - Soft tissue work is especially important for shoulder health.  With 17 different muscles impacting shoulder position and function, there can be a mess of problems.  Tissues can get beat up and dense so using some soft tissue work, especially on the pec minor, posterior rotator cuff, lats, levator scapulae, and cervical spine/1st spine.  Doing soft tissue on these areas can instantly lead to lead to ROM increases and can make stability and strength exercises more effective.

Rotator Cuff – While we talked about how most rotator cuff problems probably are better treated with scapular mobility and stability work, but you still need proper strength, endurance, and timing in your rotator cuff complex. 

You need a strong posterior cuff (infraspinatus and teres minor) for decelerating the rapid speeds of internal rotation, but you also need a very strong anterior cuff (subscapularis) to both depress the humeral head during overhead work and prevent anterior translation of that head.  Now don't get carried away with and start killing Internal and External rotations all day, the Cuff also needs good timing, and remember it's most important job is to keep the humeral head centered in the glenoid fossa.  Some favorites include some distraction or proprioception work, and for endurance farmer's walks and suitcase carry's are awesome.

Breathing Patterns – Breathing patterns are soooo important and it can greatly effect shoulder health.  Diaphragmatic breathers have much better shoulder function than those who breath into their chests, and a big reason for this is rib and torso positioning.  Remember, the shoulder does connect to the ribcage and breathing patterns can strongly influence position and function of the many of muscles of the collar bone, scapula, and ribs and all of these can play a role in shoulder health.

Alrighty hope you enjoyed!  Also remember to sign-up for BBA updates to stay on top of great articles like this one being posted!  Also like our Facebook page and join in some discussion!  Until next time Go Get Em!


More Sources - These guys below are the shoulder gurus in the sports performance industry.  Eric Cressey coaches mainly baseball players and his experience with overhead athletes is tremendous.  Mike Reinold was a PT for the Red Sox's and he's worked with Cressey on a number of awesome products.  Check them out for real great information on all things shoulder.

Eric Cressey
Mike Reinold