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Debunking

Squat and Deadlift Myths

Hunter Stark, PT, DPT, COMT, CSCS

04 March 2017

Andrews Institute Rehab Symposium: LE

Objectives

• Understand the fundamental movement patterns and

differences between the squat and hip hinge

• Discuss the role of the squat and deadlift in activities of daily

living

• Discuss various myths and misconceptions of each movement

pattern

What is a deadlift or hinge? What is the Deadlift?

• Deadlift – a.k.a., “Hip Hinge”

– Most fundamental, natural and authentic way to move

something heavy in a safe and effective way

– Fundamental Exercise

• Modifiable

• Promotes core stability

• Demands good posture

• Promotes shoulder stability

• Forces the hips to be the main driving force

What is a squat?What is a squat?

• Squa:ng ≠ exercise

• Squatting = movement pattern

• Natural movement used to investigate things and

transition from the floor <> standing

– Culture has changed the squat from a Pattern to an Exercise

– Moving weight has become more important than moving

well

– Modern solution = modify it to fit our limitations

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Squat vs. Deadlift

Deadlift

• Hips Back

• Vertical Tibia

• More horizontal trunk

Squat

• Hips Down

• Angled Tibia

• More vertical trunk

Squat vs. Deadlift

• Deadlift– Not a huge amount of stress onto joints

– High tension onto fascial slings/muscular system

– Primary movement for lifting, moving objects and acquiring a good athletic position

• Squat– Maxes out a few joints

– High mobility demand

– Transitional activity

• “Train the Deadlift; Maintain the Squat”– Gray Cook

Myths and the Research

The Controversy Begins

• Klein KK. “The deep squat exercise as utilized in weight training for athletes and its effect on the ligaments of the knee.” J. Assoc. Phys. Ment. Rehabil. 15:6-11, 1961

– Hypothesis:

• The deep squat exercise will stretch ligaments of the knee and cause knee instability

– Methods:

• 128 experienced weightlifters who did full squats and 386 subjects who did not compete in weightlifting nor did full squatting

• The study used a device, which Klein had built, to measure the amount of medial or lateral give in the knee

“Squats have a debilitative effect on the ligament structures of the knee…”

• Results

– Greater MCL and LCL instability in weightlifters when compared to controls

• Conclusions

– Deeps squats will cause increased instability of the knee

– Parallel squats should be used in place of deep squats

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The Klein Fallout

• Highlights of the study were published widely

in lay-journals

• Thousands of coaches who were suspicious of

weightlifting felt vindicated

• General acceptance in the medical community

of Klein’s data

• U.S. Marine Corps recommended the removal

of squats from the physical fitness program

Assumption:

Klein’s tests are reliable and valid

• Henning et al., (1985)

• “The squat generated lower ACL strain compared with walking or jogging, it was concluded that the squat was a low risk exercise in rehabilitation of the ACL”

• Steiner et al., (1986)

• “In conclusion, basketball players and distance runners experienced a transient increase in anterior and posterior laxity during exercise. Powerlifters doing squats did not demonstrate a significant change in laxity”

• No increased laxity in powerlifters

• Increased laxity in basketball players and runners

• Chandler et al., (1989)• 8-week full squat program did not result in increased instability

• Escamilla et al., (2001)• “The squat does not compromise knee stability, and can

enhance stability if performed correctly. Finally, the squat can be effective in developing hip, knee, and ankle musculature, because moderate to high quadriceps, hamstring, and gastrocnemius activity were produced during the squat”

• Schoenfeld BJ, (2010)• “In conclusion, there is scant evidence to show that deep squats

are contraindicated in those with healthy knee function.”

Shear and Compression?

• Anterior and Posterior shear forces increased with depth of squats but within tolerable limits for intact PCL/ACL

• Shear and compressive forces on the knee increase with speed of descent, load and fatigue

• Shear and compressive forces are reduced in experienced lifters

– Escamilla et al., 2000

• Higher relative posterior shear forces are the result of initiating the turning point of the squat at 80-90 degrees as compared with the deep squat at 130 degrees

– Nisell R (1986), Escamilla RF (1998), Escamilla (2001)

When to avoid training the squat?

• Mobility restrictions

– Restrictions of the ankle, knee or hip

• Pathologies

– Meniscus injuries

– PCL involvement

– Hip impingement (labral tear or bone spur)

– Chondromalacia patella (depending on location)

– Advanced symptomatic osteoarthritis

- www.aaronswansonpt.com

Meniscus

PCL

CP

Symptomatic

OA

FAI

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All squats should look

the same, right?

• No, not really…

– Phylogenetics

• Evolutionary history of our species

– The way our bodies have evolved over time has resulted in the movement pattern of the deep squat

– Ontogenetics

• Developmental history of an individual

– Interaction of genetics, developmental programming, and environment on physical form throughout a lifespan

– Culture plays a huge role on whether we can squat effectively

Example

2-year old 70-year old

Phylogenetics Ontogenetics

“Squatting is not bad for your knees; the way

you are squatting is bad for your knees”

Squat Variations

• All the same pattern but different variations:

– “Natural” Bodyweight Squat

– Goblet Squat

– Split Squat

– Barbell Back Squat – hi and low bar

– Barbell Front Squat

– Box Squat

– Safety Bar Squat

– Belt Squat

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Squatting Hurts! Can I just

do machines instead?

• Double or Single-leg Squat

– Increased co-contraction of Quad:HS

– Increased neuromuscular adaptation and stability demands

• Increased performance in speed-strength tests as compared to machine strengthening

• Leg Press / Smith Machine

– Increased ease of use with less stability demands

– Quadriceps dominant activity

– Similar tibiofemoral compressive and shear forces as compared to squatting

– Less posterior shear forces noted – PCL rehabilitation

I’m pretty sure

deadlifting will hurt my

back

• Partially False

– Lifting with inadequate mobility/stability,

technique and preparation or readiness will injure

the back– McGill, S. (2007)

– Lifting with pre-requisite abilities can provide

protection for those who have previously injured

their back

– Psychological assistance

• Final step in back rehab program

• Assist with regaining confidence in their back

• Feel a load distributed across the tissues of the back,

hips, and legs.

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Squatting and

deadlifting are not

appropriate for a

person my age!!

• False

– Wolff’s Law: if you never load you never grow

• Osteogenesis

– Critical automatic balance reactions

• Increased fall risk without the ability to hinge at the hips

(squatting, lunging, deadlifting)

• Improvement in:

– Ankle Balance strategy = squat

– Posterior weight shift = deadlift

– Single leg weight-shift or step-strategy = lunge

– Reduces movement substitution and compensations

• Increased movement compensation = repetitive micro-

trauma to joints

• Grandma’s purse, suitcase or grandchild is heavier than most of the weights that we get them to lift

TRAIN FOR DAILY LIFE –

NOT LIFTING COLORFUL WEIGHTS

Summary

• Negative attitudes towards squats are the result of

generations of misinformation and “meathead”

approaches to teaching squat and deadlift technique

• Hip hinging and squatting are movements before they

are exercises

• Safe when trained appropriately

• Appropriate for all ages if proper progressions or

modifications are made

Questions, Thought, Concerns, or just want to Chat?

Hunter.Stark@bhcpns.org

601-540-1086

https://preventativeperformance.wordpress.com

References• 1. Berglund L, Aasa B, Hellqvist J, Michaelson P, Aasa U. Which patients with low

back pain benefit from Deadlift training? Journal of Strength and Conditioning Research. 2015;29(7):1803–1811. doi:10.1519/jsc.0000000000000837.

• 2. Wilk KE, Escamilla RF, Fleisig GS, Barrentine SW, Andrews JR, Boyd ML. A comparison of Tibiofemoral joint forces and Electromyographic Activity during open and closed kinetic chain exercises. The American Journal of Sports Medicine. 1996;24(4):518–527. doi:10.1177/036354659602400418.

• 3. Wirth K, Hartmann H, Sander A, Mickel C, Szilvas E, Keiner M. The impact of back squat and leg-press exercises on maximal strength and speed-strength parameters. Journal of Strength and Conditioning Research. 2016;30(5):1205–1212. doi:10.1519/jsc.0000000000001228.

• 4. Schwanbeck S, Chilibeck PD, Binsted G. A comparison of free weight squat to Smith machine squat using Electromyography. Journal of Strength and Conditioning Research. 2009;23(9):2588–2591. doi:10.1519/jsc.0b013e3181b1b181.

• 5. FunctionalMovement. Balanced Body Series - Maintain the Squat - Train the Deadlift. FMS. http://www.functionalmovement.com/articles/fitness/2011-12-12_balanced_body_series_-_dead_lifting. Accessed February 12, 2017.

• 6. Bredin SSD, Dickson DB, Warburton DER. Effects of varying attentional focus on health-related physical fitness performance. Applied Physiology, Nutrition, and Metabolism. 2013;38(2):161–168. doi:10.1139/apnm-2012-0182.

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References• 7. Swinton PA, Stewart A, Agouris I, Keogh JW, Lloyd R. A Biomechanical analysis of

straight and hexagonal barbell Deadlifts using Submaximal loads. Journal of Strength and Conditioning Research. 2011;25(7):2000–2009. doi:10.1519/jsc.0b013e3181e73f87.

• 8. Henning CE, Lynch MA, Glick KR. An in vivo strain gage study of elongation of the anterior cruciate ligament. The American Journal of Sports Medicine. 1985;13(1):22–26. doi:10.1177/036354658501300104.

• 9. Escamilla RF. Knee biomechanics of the dynamic squat exercise. Medicine and Science in Sports and Exercise. January 2001:127–141. doi:10.1097/00005768-200101000-00020.

• 10. Steiner ME, Grana WA, Chillag K, Schelberg-Karnes E. The effect of exercise on anterior-posterior knee laxity. The American Journal of Sports Medicine. 1986;14(1):24–29. doi:10.1177/036354658601400105.

• 11. Schoenfeld BJ. Squatting Kinematics and Kinetics and their application to exercise performance. Journal of Strength and Conditioning Research. 2010;24(12):3497–3506. doi:10.1519/jsc.0b013e3181bac2d7.

• 12. Cook G, Burton L, Torine J. Movement: Functional movement systems: Screening, assessment and corrective strategies. United Kingdom: Lotus Publishing; September 30, 2011.

• 13. McGill, S. (2007). Low back disorders: evidenced-based prevention and

rehabilitation. Human Kinetics.

• 14. Klein KK. “The deep squat exercise as utilize in weight training for athletes and its effect on the ligaments of the knee.” J. Assoc. Phys. Ment. Rehabil. 1961; 15:6-11.

• 15. Nisell R, Ekholm J. Joint load during the parallel squat in powerlifting and force analysis of in vivo bilateral quadriceps tendon rupture. Scand J Sports Sci. 1986; 8:63-70.

• 16. Escamilla RF, Fleisig GS, Zheng N, et al. Biomechanics of the knee during closed kinetic chain and open kinetic chain exercises. Med Sci Sports Exer. 1998; 30: 556-69.

• 17. Escamilla RF, Fleisig GS, Zheng N, et al. Effects of technique variations on knee biomechanics during the squat and leg press. Med Sci Sports Exerc. 2001; 33: 1552-66.

• 18. Escamilla et al. (2000) Biomechanics of powerlifting and weightlifting exercises. Exercise and Sports Sciences. WE Garrett and DT Kirkendall (Ed.), Lippincott Williams and Wilkins.

“Squatting is not bad for your knees; the way

you are squatting is bad for your knees”

• Restriction of forward knee displacement

increases anterior shear force on

intervertebral discs and tensile force on

intervertebral ligaments.

– Potvin, McGill

The Klein Fallout

• Klein’s findings were not valid, accurate or reliable

• Klein’s findings have been handed down through generations of coaches, doctors, PE instructors and everyday people

• Once something is in print, no matter how inaccurate it may be, it can take years to remove the damage that it may cause

• Ankle

– Weakness of medial gastroc, tib. Anterior, or tib. Posterior may decrease ability to control knee valgus and foot pronation motions

– Mobility deficits into DF can lead to a heels elevated squat leading to increased ACL strain and dynamic valgus of the knee

• Hip– Forward trunk lean significantly increases hip torque during squatting

(302.7N vs. 28.2N)

• Spine

– Squatting with a flexed lumbar spine decreases the moment arm for the lumbar erector spinae, reduces tolerance to compressive load, and results in a transfer of the load from muscles to passive tissues, heightening the risk of disc herniation

– Flexed lumbar spine increases shear forces of intervertebral vertebrae

– Increased IAP = Decreased lumbar load and improved spinal stabilization