Tout dans la vie est une question d'équilibre d'où la nécessité de garder un esprit sain dans un corps sain.

Discipline-Volonté-Persévérance

Everything in life is a matter of balance therefore one needs to keep a healthy mind in a healthy body.

Discipline-Will-Perseverance.

E. do REGO

Saturday, May 7, 2011

The New Science on Squatting and the TRUTH About Assessing and Teaching the Squat – Interview w/ Dr.Mark McKean � Nick Tumminello Fitness | Baltimore MD Personal Trainer | Sports Performance & Bodybuilding


The TRUTH About Squating – Interview with Dr. Mark McKean

Who are you and why should we listen to you?

I started my career as a physical education teacher and taught high school PE for just over 3 years extending my interest in sports coaching and performance with high school athletes. In the late 80’s I changed careers to work as a fitness instructor and strength coach. I have now worked as a PT for 23 years and strength coach for 21 years. I have owned a number of fitness related businesses including fitness centres, studios, PT businesses, and an instructor training organisation. I have since coached athletes to international level competition in 18 sports and helped some of these win both Olympic and World Championship medals in 5 sports. In 2009 I completed my PhD in sport science focusing on movement timing and coordination of the human body and the strength ratios, muscle balance, and ROM about key joints. Since then I have set up a research program at the University Sunshine Coast specifically to research practices and issues within the fitness industry so we can feed back good quality scientifically validated information to instructors and trainers.
In particular the key lower body activity I used in my research was the back squat exercise. I have since had 2 papers published in JSCR on squat movement pattern and have also finished a further 2 studies on squatting soon to be published as well. Over the last 15 years I have presented over 500 lectures and workshops both nationally in Australia and internationally on posture, strength, flexibility, and personal training. One of those in Beijing last year was where we got to meet and spend some time with our great friends in China.

When you and I met (while both presenting in Beijing China), you had mentioned your research on the Squat. Can you please give us the bullet points of your squat research studies?

The squat research really came about as a result of the workshops and lectures I was presenting and I found so much conflict between instructors and coaches regards the techniques and cues used to teach and correct the squat movement pattern. I always had the opinion instructors were over teaching the squat and not letting the individual develop their own pattern based on their own physical structure. Too many cues, too many restriction, etc just seemed to go against all normal motor development strategies. As a result the last 5 years has seen my research program do a number of studies into the squat pattern and to look more closely at how people squat and what the timing and coordination strategies are developed to perform the squat.
Some of the key findings we have found probably confirm what many experienced strength coaches and lifters already know but was not always carried over to the fitness industry.
With so many key outcomes from the research here is a brief summary of what I have found so far.

Set Up

- One of the more obvious but less expected findings was that in every case, as soon as a loaded bar was placed across the rear shoulder region prior to the commencement of the downward phase of the squat, the lumbar spine lost its normal or natural curve.
- It appears that the normal response to a loaded bar on the shoulders is for the human body to adjust its posture so as to align the changed centre of mass now including the loaded bar so that the spine is more aligned directly underneath the load. Check it out next time you train a client and watch how the person’s lumbar spine changes once the bar is taken onto the back.

Knees

- The knees must move first and must forward to a point where the hip and knee joints can then coordinate with almost perfect precision.
- This means DON’T stop the knees moving over the toes but also don’t make a fuss about whether they do or don’t, just let the knees move into a position that allows the next part of the squat to become more coordinated. Some of our subjects kept their knees above the toes but other went forward of the toes by as much as 17 cm, with the average being 6-9 cm in front of the toes. But the knees always appear to move first and initiate the squat.
- This was also evident when we looked at the angular velocity of the shank and found that the shank did not move in a smooth way through the ascent and descent but moved in way that suggests the shank and knee are used by the body to control centre of balance and adjust total body position to remain stable and coordinated. Other research has also shown that anterior tibialis also contracts first to initiate the shank moving forward and this supported by our findings also.
- Mediolateral knee alignment does not remain in a constant width aligned with toes but tends to vary its width at different stages of the descent and ascent by between 5-9 cm. Again this appears to be important trainers and coaches should not prevent people from letting knees move slightly in or out as this assists with keeping the hip and knees in a coordinated movement pattern.

Gender differences

- Men and women definitely have different strategies in squatting and the timing of when each joint and segment reaches it maximum is different in all squat variations.
- Knee angle differ the most between males and females and this appears to be influenced most by different segment lengths of the lower limbs.
- Tall women tend to alter knee angles and tall men tend to alter hip angles when squatting.
- To adjust body position men tend to alter trunk angle and women tend to alter pelvis position
- Men appear to be more inherently stiff in the lumbar spine and women tend to be looser through the lumbar spine suggesting that women who squat will benefit from a good core strengthening program.

Lumbar spine

- Even with our experienced squatters most found it hard to maintain neutral or semi-flat lumbar curve.
- Our squatters went below parallel thigh and once below this depth it appears that the lumbar spine actually reverses its curve and becomes kyphotic.
- It’s not known if this is a good practice and loads used in our study were not 1RM but its concerning and needs further investigation to study or predict how this changes loading into the lumbar spine as all current models are done with neutral or semi curved lumbar spine.

Segment lengths

- Segment lengths definitely influence the squat movement pattern with height and trunk length being two of the most influential determinants to technique.

Overall squat strategy

- From a number of studies it appears that the main movement strategy developed by the brain to allow us to squat revolves around allowing the hip and knee to move with almost perfect precision.


- Movement of the knees, lumbar and sacrum regions, and shank all occur so that hip-knee coordination occurs evenly and smoothly.

What was your most surprising finding from your squat research?

The thing that really hit home to me about the complexity of such a gross movement was the manner in which the shank angle changed so much as a means to create stability and a constant centre of mass. This has never been reported or even discussed in the literature previously but when you look at the graphs of the speed of the hip and knee and the lines are so smooth and change perfectly and then you see the shank velocity going up and down and you match this with the centre pressure of mass, it really reinforced how important it is to be stable but also how clever the human movement pattern is to allow one component to almost be responsible for controlling this stability.

What conclusions has your squat research lead you to?

Wow that’s a big question. I would suggest my research has confirmed my previously held opinion that most trainers get it wrong with respect to the knees when squatting. Too many times I hear trainers and coaches tell their athletes or clients to keep the knees behind the toes and to keep them aligned. One of the key things I would suggest to these people is to let the knees move more freely and coach your athlete or client to perfect the coordination between the hip and knee rather than isolate the coaching of good technique to specific aspects of things like ‘break from the hips first’ or ‘keep the knees behind the line of toes’. Also allow squatters to develop a pattern over time rather than over teach and over correct too early before they have developed a coordinated movement based on experience.

Is there only one way “right” way to squat?

Good question…. in my opinion there is no best way to squat if you refer to specifics such as joint angles, or feet position etc, but I do believe there are ‘ideal’ strategies to teach. These include things like I have just mentioned with letting knees move freely and aiming to achieve perfect coordination between hip and knee joint angles and time at which the maximum of these angles occur.
Also know that taller people will squat differently to shorter people and most experienced coaches will know this. In my first bear of strength coaching I did some work experience with a national basketball team and these guys just could not squat, and over time I realised why and this research for me explains why this happens.

Should men and women squat differently?

When teaching men and women to squat I still go with the overall strategy of good squatting practice, but I’m also aware that the genders will correct and adjust position differently. The big indicator for differences with genders is the knee angles and subsequent trunk position. If you keep an eye on this you will see what I mean.
The other interesting thing I haven’t mentioned yet is that women tend to achieve more perfect coordination in all squat variations of load and stance, but men tend to achieve a better level of coordination only when squatting with heavier loads. It’s as if the load tends to optimise their patterns by either; allowing muscles and fascia to be stretched by the load, or with stronger stiffer muscles the extra load provides equal tension and improves coordination. This doesn’t mean go and load up every male’s squat weight because they squat poorly to assist with coordination, but be aware that the difference between unloaded squats and loaded squats will look more different in males than in females.

What do you think are some of the biggest mistakes trainers & coaches make when teaching or assessing the squat pattern?

Over teaching or over cuing. This really comes about from the way most professionals are taught and during this process they are told how to squat rather than how to ‘teach’ people to squat. I hear professionals provide clients with as many as 6-8 teaching cues, and then wonder why the person moves so slowly and in such a disjointed manner. The poor client is so busy trying to put everything they are told into a pattern that they have to be slow and the movement looks stiff or disjointed. Typically I teach people to get into the correct start position and then discuss what the correct bottom position looks like, by either talking it through or showing them, then allow the person to practice moving between these two positions. I also allow about 8-12 reps to achieve a more consistent pattern before I step in and coach. By doing this the person knows the two ends of the movement and has to develop their own strategy to move between these points. It generally takes 8-12 reps to develop this and only after that should you try and coach for an improved pattern rather than a predetermined pattern or one size fits all approach.
Assessing the squat pattern also has issues if you come from the predetermined or 8 cues approach as you will then typically look for a set sequence of events in the squat rather than consider the overall movement and how coordinated it might be which in the end is the ultimate aim, i.e. to squat smoothly and safely. There will always be issues related to poor flexibility and poor stability or balance that you can pick up on, but to my mind I want my clients to be smooth an d efficient in the squat as it then allows me to develop loading parameters to suit their goals.

What do you currently have going on – What can we look forward to in the near future form you?

After the squat research we have now moved onto looking at the shoulder press exercise. Again, more from industry feedback and behaviours, the behind the shoulder press exercise has received a lot of bad press even being banned by some industry leaders, but when I went looking for research to support why this exercise was so bad, I found nothing.
We recently completed data collection and have been crunching the data and running the stats. Our aim is firstly to compare the passive ROM about the shoulder girdle with the active ROM required to perform both in front and behind the head shoulder press. We have also collected data on the behaviour of the lumbar and thoracic spine, as well as scapula during both variations, and we also decided to use 3RM loads and 8RM loads to see if load altered this pattern. We are currently writing up the results and looking to submit this for publication within the next month or so.
I’ve always wanted to do something similar for chin-ups so perhaps that will be the next project. But we’ve also got a lot of other research going on…
- The ability of PT’s to become health educators and fight obesity by testing their nutritional knowledge
- Comparing constant interval training in elderly
- Using the WiiFit as a training tool for elderly
- Quantifying the value of group fitness classes to a variety of health measures
Once we get these done I’m happy to pass on our findings as well. Perhaps Nick you can even become part of our research board and help suggest ideas that require research that we can work on together.
Cheers and thanks for the chance to answer some questions on our research and specifically the squat.
Mark McKean PhD CSCS

Here A few of my personal favorite take-home quotes from Mark’s interview:

- “When teaching men and women to squat I still go with the overall strategy of good squatting practice, but I’m also aware that the genders will correct and adjust position differently”
- “The other interesting thing I haven’t mentioned yet is that women tend to achieve more perfect coordination in all squat variations of load and stance, but men tend to achieve a better level of coordination only when squatting with heavier loads”
- “Too many times I hear trainers and coaches tell their athletes or clients to keep the knees behind the toes and to keep them aligned. One of the key things I would suggest to these people is to let the knees move more freely and coach your athlete or client to perfect the coordination between the hip and knee rather than isolate the coaching of good technique to specific aspects of things like ‘break from the hips first’ or ‘keep the knees behind the line of toes’. Also allow squatters to develop a pattern over time rather than over teach and over correct too early before they have developed a coordinated movement based on experience.”

I HIGHLY Recommend You to Go Back and Read this interview AGAIN!

You know how we do things here at NickTumminello.com – We always bring you nothing but the best information and consistently exceed your expectations. Mark’s interview above is certainly no exception!
Since Mark’s interview is so jam-packed with so much usable information on teaching the squat exercise and assessing the squat pattern. I suggest reading this interview a few times over in order to ensure you’ve gotten every last thing you could out of it.

Contact Mark McKean

Be sure to check out Mark’s website, his blog, and his published research & reviews.
You can also friend him on Facebook here.

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