Are full squats bad for the knees?

August 2, 2009 7:48 PM

Are full squats (below parallel) bad for the knees?

I started a workout routine several months ago, and recently changed my squat form so that my thighs would go past parallel when bending down.
A friend of mine told me off, saying that "anyone who knows anything" about lifting knows that such form is "very bad" for the knees. I tried to explain my point to two other (male) friends, who then both affirmed my first friend's sentiments by telling me I was very inexperienced.


MeFites, help me determine whether my research so far is correct! Links to credible sources are much appreciated (for possible gloating to said friends).

Thanks!

posted by pyrom to health & fitness (31 comments total)

Your friends are morons.

Squats

Fitness Myths
posted by Loto at 8:03 PM on August 2

no

NO NO NO NO NO NO NO NO

Your friends are wrong. They are stupid and they are wrong.

Squats that go below parallel are not only not-bad for your knees, they are good for your knees. They strengthen the muscles of your legs around your knees through their full range of motion, to better add to the support structure of the joint. In fact, stopping the squat above parallel results in undue stress on the joint, both by removing a large portion of the exercise that involves the hamstrings and glutes and creating muscular imbalances, and by producing excess shearing forces on the knees because you stop the descent early, before the hamstrings have a chance to kick in.

Quoting from Starting Strength (by Mark Rippetoe and Lon Kilgore):

In a partial squat, which fails to provide a full stretch for the hamstrings, most of the force against the tibia is upward and forward, from the quardirceps and their attachment to the front of the tibia below the knee. This produces an anterior shear, a forward-directed sliding force, on the knee, with the tiba being pulled forward from the patellar tendon and without a balancing pull from the opposing hamstrings. This shearing force--and the resulting unbalanced strain on the prepatellar area--may be the biggest problem with partial squats. Many spectacular cases of tendinitis have been produced this way, with "squats" getting the blame.

Always take your squats to parallel or below, as deep as you are able while maintaining a good back postion without undue rounding. If you can't get to at least parallel, drop to a weight to where you can, and if you can't get to parallel with no weight, then you need to stop squatting and improve your flexibility.

Squats CAN be damaging to your knees, however, if you have previous knee problems and insist on maxing out your squats while the knee problems continue, or if your knees are not tracking over your toes. If at any point during your squat your knees are not following the direction where your toes are pointing--bending inwards or outwards--then that's no good and you are putting yourself in danger of future knee issues.
posted by schroedinger at 8:03 PM on August 2 [1 favorite]

Helpful?

I confess I've never seen anything backed by more than online authority.

However, I have had my squat form reviewed by a powerlifting coach who pronounced it ok (though not competition standard) and I go below parallel.

If you're going to go low, the advice I have distilled from the mighty interwebs is:
- reduce weight while you work on your new form
- take it slow
- don't have anything under your heels (I bet your friends recommend that too)
- get the path of knees over toes correct with knees neither splaying nor drawn in
- don't rest on your calves

I don't have a huge squat - about 1.5 x bodyweight - but I do have an exercise regime that is somewhat abusive to knees (cycling, capoeira) and I have had exactly one knee injury, a minor sprain from an inattentive deadlift descent. Personally I would go for it and ignore my friends, but seek advice from a lifting coach, not your ignorant mates.
posted by i_am_joe's_spleen at 8:05 PM on August 2

They have no idea what they are talking about.

Best explanation I've read is found in Starting Strength. Maybe they have it at the library? Here is the wiki article, it's not quite as good as the book but gives a good overview.

Basically it's just one of those old wives tales that makes no sense once one actually looks at the mechanics of the movement.

Ask your friends if they think competitive lifters would be purposely doing "very bad" lifts that would hurt themselves. From pg 18 in the IPF Rulebook "Upon receiving the Chief Referee’s signal the lifter must bend the knees and lower the body until the top surface of the legs at the hip joint is lower than the top of the knees."

I guess Olympic lifters and powerlifters don't "know anything" about lifting...
posted by teishu at 8:07 PM on August 2

Also also, when I see "knees over toes", I don't mean "Your knees should not cross over your toes", but "Your knees should not be going left or right over your toes." They shouldn't be buckling in, for instance.
posted by schroedinger at 8:08 PM on August 2

Ask them for citations -- from medical literature -- that full-depth squats damage the knees. Krista at Stumptuous says she hasn't found any such evidence in the literature, and cites evidence against squatting just to parallel.

Learning the Squat 1: Debunking the Myths

myth #1: squatting must not be done with a full range of motion or you will hurt your knees.

This is probably the worst myth of all. It’s one of those “well known facts” which is mysteriously unsupported in the research (it’s a well known fact that as soon as you say “it’s a well known fact”, you won’t be able to back it up). According to this myth, full squats (a squat in which the knee joint is taken through a full range of motion, so that at the bottom the hamstrings make contact with the calves) are inherently dangerous, particularly to the knee joint.

While biomechanical research does support the fact that forces on the connective tissues of the knee increase with the knee angle, particularly on the posterior cruciate ligament, there is no evidence that these increased forces actually lead to injury. There is no direct evidence that full squatting causes or even exacerbates knee pain nor damage. I do not know of a single documented case where full squatting led directly to knee injury. Not one! Which is pretty amazing, considering that the clinical literature is positively littered with injury narratives. You’d think we’d see some evidence, but there is nothing, nada, zero. Studies of Olympic weightlifters and powerlifters, both of whom squat with heavy loads, show no increased risk of knee damage in either population. Olympic lifters, in particular, regularly drop to full depth under hundreds of pounds, perhaps as often a hundred times a week or more, for years, and yet their knees are healthier than those of people such as skiiers, jumpers, or runners. No study, short or long term, has ever shown an increase in knee laxity from deep squatting. ...

In fact, there is strong evidence that squatting actually improves knee stability! The increased strength, balance, and proprioception from regular squatting can make a substantial contribution to keeping knees healthy. Progressive overload (beginning with a light load, then increasing gradually as the trainee is able) assists in strengthening connective tissues and muscles surrounding the joint.

Most interesting to me is the problem with what is usually recommended as “safe”: squatting to parallel. At parallel (where the thigh is parallel to the floor, higher than the depth of a full squat by about 30 degrees), the compressive forces on the patella (kneecap) are actually at their highest (Huberti & Hayes, Journal of Bone Joint Surgery, 1984: 715-724). Decelerating, stopping, and reversing direction at this angle can inspire significant knee pain in even healthy people, whereas full squats present no problem. Another exercise which is supposedly “safer” is the leg extension, even though patellar tension and shear forces on the knee joint are demonstrably higher with such an exercise.

posted by maudlin at 8:11 PM on August 2

Yes it's fine if you go past parallel, your body fully functions in that way already.

Another common saying is that your knees can't travel over your toes when lunging, but if you walk up stairs then this happens all the time.
posted by P.o.B. at 8:11 PM on August 2

"Anyone who knows anything about lifting" would know that Arnold, Dave Draper and everyone else who learned to train before the mid 1960's regularly performed full squats.

Your friends essentially believe an urban legend that has some basis in terrible research from the University of Texas by Dr. Karl Klein who published "The deep squat exercise as utilized in weight training for athletes and its effects on the ligaments of the knee" in 1961. He compared those who performed full squats (all of the lifters) to people who did not lift weights and found the weightlifters to have more laxity in the ligaments of the knee. He then seemingly arbitrarily recommended limiting the depth of squats to parallel. Meyers tried to reproduce his results in 1971 by testing the laxity of medial collateral ligament and found both types of squats decreased laxity "Effect of selected exercise variables on ligament stability and flexibility of the knee". In addition to Bill Starr's trashing of Klein's ideas, Jason Shea has an excellent dissection of the issue.

The idea in itself is pretty ridiculous at face value, no other joint in the human body needs a limiting of the pain free range of motion to prevent injury during weightlifting (unless you happen to be lifting weights with guys who don't touch the bar to their chest when they bench, or press to lockout in shoulder presses and consider a pullup bringing your forehead to the bar). In addition there are plenty of people all over the world who use squat toilets every day and unless there is some unknown epidemic of knee disorders, exhibit no detriment at all. Furthermore, there are plenty of athletes who regularly perform full squats during training and exhibit no greater incidence of knee disorder than other athletes. Here is a paper looking at injury in elite weightlifters over 6 years, knee injuries made up about 30% of the injuries, and of the knee injuries only 8.4% were something other than strain or tendonitis.

More from Alwyn Cosgrove and exrx.net's take which references Kreighbaum's work on how to perform a full squat with little risk of injury.
posted by zentrification at 10:49 PM on August 2 [2 favorites]

I used to mostly perform full squats (by which I mean squats to the point where the thigh rested on the calf), and after a few months of doing them, experienced occasional discomfort in my knees; I was advised not to squat below the point where my thighs were parallel to the floor, and after changing my exercises the problem went away.

Possible causes for my anecdotally-reported-on-the-internet problems include:
1. Going below parallel at all
2. Going so low that the body could rest on the calves (A bad thing according to this page on the internet)
3. It was a form issue unrelated to squat depth, which happened to be fixed when I changed my form.
4. That I have an underlying knee problem, which only manifests itself when performing full squats.
5. The problems were caused by something else, and the fix coinciding with my change in form was a coincidence.
6. That I am (as Loto says) a moron, or (as schroedinger says) stupid and wrong.

In any case, after I stopped performing full squats my knee discomfort went away, so you could go ahead and perform squats as people above are suggesting, and change your form only if you encounter problems.
posted by Mike1024 at 4:46 AM on August 3

Squats below parallel can be bad for your knees if you use bad form. But if you read Starting Strength by Rippetoe and Kilgore as other people have mentioned, you will learn good form and you won't have any problems. The basic idea is that you take a wide stance and point your feet out at an angle, so that as you squat below parallel, your groin muscles support you and store elastic energy. Then as you come up, your groin muscles release that elastic energy and you bounce up out of the squat. But you should really read the book to get a full explanation. Also, you might want to check out the Starting Strength wiki.
posted by qmechanic at 4:56 AM on August 3

One of the big problems with weight lifting is that there's a lot of received wisdom and not a lot of long term studies to back them up, so people go with what sounds right, which may not actually be right. For example, Stumptuous and Starting Strength are popular on MeFi, but neither Mark Rippetoe nor Krista Miller has any particular training in orthopedics or exercise physiology and knee injury appears to be outside of Lon Kilgore's area of specialization. If you google Mark Rippetoe, the 5th result is "Mark Rippetoe sucks! - Iron Addicts Forums".

Similarly, the idea that since people like Arnold or Olympic weightlifters do something, it can't be bad for you is equally problematic. Arnold admitted to steroid use that may have caused heart problems, and Olympic weightlifting puts you at risk for horrific dislocation injuries. The world's strongest man powerlifting types are notorious for early death from heart disease. People do lots of things that may be unhealthy in the long term for short term benefits.
posted by electroboy at 7:45 AM on August 3

i think qmechanic has it- doing that maneuver has the potential to be bad if your center of gravity is wrong. I would suspect this is easy to do on a machine, not so easy to do with free weight.
posted by gjc at 7:45 AM on August 3

Mark Rippetoe nor Krista Miller has any particular training in orthopedics or exercise physiology and knee injury appears to be outside of Lon Kilgore's area of specialization.

Mark Rippetoe has, however, been training novices to squat for 25 years.

Similarly, the idea that since people like Arnold or Olympic weightlifters do something, it can't be bad for you is equally problematic. Arnold admitted to steroid use that may have caused heart problems, and Olympic weightlifting puts you at risk for horrific dislocation injuries.

No one is arguing for steroid use. The point is that nobody squats as frequently or as deep as Olympic weightlifters. The fact that they don't all have awful knee problems is instructive.
posted by ludwig_van at 8:19 AM on August 3

The fact that they don't all have awful knee problems is instructive.

I must've missed the part where that fact was demonstrated.

Anyway, here's some actual research:

Knee osteoarthritis in former runners, soccer players, weight lifters, and shooters

Conclusion. Soccer players and weight lifters are at increased risk of developing premature knee osteoarthritis (OA). The increased risk is explained in part by knee injuries in soccer players and by high body mass in weight lifters.

Joint moments of force and quadriceps muscle activity during squatting exercise

Conclusion: We conclude that knee joint load can be limited by doing parallel instead of deep squats and that this will not decrease quadriceps muscle activity. To limit hip moment, the squat should not be deeper than 90°.

Effect of Knee Position on Hip and Knee Torques During the Barbell Squat

Practical applications: Although restricting forward movement of the knees may minimize stress on the knees, it is likely that forces are inappropriately transferred to the hips and low-back region. Thus, appropriate joint loading during this exercise may require the knees to move slightly past the toes.

Effects of technique variations on knee biomechanics during the squat and leg press

Conclusions: The greater muscle activity and knee forces in the squat compared with the LPL and LPH implies the squat may be more effective in muscle development but should be used cautiously in those with PCL and PF disorders, especially at greater knee flexion angles. Because all forces increased with knee flexion, training within the functional 0-50° range may be efficacious for those whose goal is to minimize knee forces. The lack of ACL forces implies that all exercises may be effective during ACL rehabilitation.

High- and low-bar squatting techniques during weight-training

The peak moments of force were flexing both for the hip and the knee. The mean peak moments of force at the hip were for the weightlifters 230 Nm (deep) and 216 Nm (parallel), and for the powerlifters 324 Nm (deep), and 309 Nm(parallel). At the knee the mean peak moments for the weightlifters were 191 Nm (deep) and 131 Nm (parallel), and for the powerlifters 139 Nm (deep) and 92 Nm (parallel). The weightlifters had the load more equally distributed between hip and knee, whereas the powerlifters put relatively more load on the hip joint. The thigh muscular activity was slightly higher for the powerlifters.


So, those are far from conclusive, but from what I can gather in a quick survey is that there's slightly higher muscle activity generated in the deep squat, but the loading on the knee joint increases with angle, so if you want to be conservative, stick with parallel.
posted by electroboy at 8:57 AM on August 3

Criticizing Mark Rippetoe and Krista Miller for their lack of formalized education is immaterial as there are plenty of strength coaches with advanced education who recommend full squats. Poliquin has bachlors in kinesiology and a masters in exercise physiology, Alwyn Cosgrove has degrees in sports performance and sports science, Mike Robertson has a masters in sports biomechanics, Ellen Kreighbaum has a PHD in sports biomechanics.

Arnold and olympic lifters are just a reference point of athletes who regularly full squatted for a number of years. There is nothing establishing a change in athletic knee health since full squatting fell out of fashion in the 1960's. The association between steroid use and heart disease is weak at best; powerlifters and WSM competitors die early because big people die early. BMI isn't nearly as specific a predictor for early mortality as bodyfat or a cholestrol profile, but it's a decent indicator. At 6'2" to 6'4" and 260-300 pounds you have a BMI in the upper thirties, which will reduce your life expectance by 4 to 10 years

The research you linked does not support the conclusion that parallel squatting is conservative. The odds ratio of arthritis in the first study say little about weighted squatting in the gym, let alone full vs parallel.

"the risk for having knee OA was increased in subjects with previous knee injuries (odds ratio [OR] 4.73), high body mass index at the age of 20 (OR 1.76/unit of increasing body mass index), previous participation in heavy work (OR 1.08/work-year), kneeling or squatting work (OR 1.10/work-year), and in subjects participating in soccer (OR 5.21)."

So don't play soccer or injure your knee to avoid arthritis. The second, third and fifth study show more force is applied to the knee during full squats, but don't correlate this with increased incidence of injury.

Performing parallel squats instead of full squats may increase your risk of injury by affecting your hamstring to quadricep strength balance, particularly ACL injuries as the hamstrings act synergistically with the ACL, and diminished hamstring strength, particularly at high velocities is associated with ACL injury.
posted by zentrification at 1:22 PM on August 3

Criticizing Mark Rippetoe and Krista Miller for their lack of formalized education is immaterial as there are plenty of strength coaches with advanced education who recommend full squats.

See my earlier point about received wisdom. There's an inordinate amount of misinformation relative to weightlifting that gets propagated by so-called "professionals". Also, Alwyn Cosgrove's "degrees" seem to consist of a bachelors, although "formal academic studies" could mean anything. Without looking too much into the rest of the people you mentioned, it appears that Kreighbaum is reasonably well respected, although I can't find much beyond her textbook and a couple interviews.

Arnold and olympic lifters are just a reference point of athletes who regularly full squatted for a number of years.

Again, I haven't seen any information about the knee health of either former olympic athletes or the governor of California to be able to evaluate that statement.

The association between steroid use and heart disease is weak at best; powerlifters and WSM competitors...

I think you're missing the point there. People sometimes value short term gain over their long term best interests. I think we can agree that steroid use has significant health consequences, and that powerlifting isn't necessarily a healthy lifestyle if you value longevity. Thus, the idea that these same people might recommend behaviors that have some short term competitive benefit at the expense of long term health, I think, is reasonable.

The odds ratio of arthritis in the first study say little about weighted squatting in the gym, let alone full vs parallel.

That's correct. I included it more because it related to knee injury and sports in general, and because it showed a link between increased body mass index (w/r/t competitive weightlifters), and knee arthritis. More general interest than a specific supporting point.

The second, third and fifth study show more force is applied to the knee during full squats, but don't correlate this with increased incidence of injury.

The second study's authors specifically recommend not moving past 90 degrees.

The third study indicates that the "no knees past toes" rule may transfer stress to your hips and back.

The fourth study indicates that squats past 50 degrees increase stresses on the knees and should be used carefully by people with posterior cruciate ligament or patellofemoral (knee) joint issues, but that all squats are ok for people with ACL issues.

And finally, the fifth study indicates that more stress is put on the knee by deep squats.

My point is not really to prove or disprove which squat is the best, just that there's research to support some squat preferences over others (based on a admittedly cursory internet search). And that the strong reaction to the parallel squat the OP got is mostly unjustified.

Performing parallel squats instead of full squats may increase your risk of injury by affecting your hamstring to quadricep strength balance

It's certainly possible, but that's not what those links say.
posted by electroboy at 2:23 PM on August 3

That was a response to your post on received wisdom. As I said, aside from Rippetoe, Miller and Kilgore whom you criticized for lack of formal education, there are coaches and researchers who have advanced education in the fields of kinesiology, exercise physiology and other sports science related topics of study who advocate performing full squats.

Steroid abuse has significant health consequences, like other drugs there are therapeutic doses with minimal side effects. The East German use of turinabol with their male athletes in the 60's is an example of relatively safe steroid use.

Most powerlifters who don't abuse steroids probably enjoy an extension of their longevity and quality of life, as strength and muscle mass are inversely related to morality. As they compete within weight classes many powerlifters are very lean, it's only the superheavy weight guys that don't care about their diet and really increase their mortality risk.

From the second study "To limit hip moment, the squat should not be deeper than 90°. What does limiting hip moment have to do with this discussion?

There is a dearth of research to suggest parallel squats have advantages over full squats. Research that demonstrates full squats place increased load on the knees and should be used carefully with PCL or PF issues is a statement of the obvious. Do we need to have a discussion of why benching or military pressing with a torn rotator cuff or labrum might be dangerous?

While you had a point that there was a lot of received wisdom in weightlifting, this isn't one of the cases. Bill Starr won the Pan Am Games, was a strength coach for the colts and oilers, U Hawaii, U Maryland and Hopkins. Poliquin is an incredibly successful coach, numerous training centers and and elite list of clientèle. These two guys didn't just read Reg Park and Anthony Ditillos advice on squatting and accept it at face value. They are frontrunners in the industry who are known for their understanding and application of the research, and the meticulous records they keep on their athletes and performance.
posted by zentrification at 5:18 PM on August 3

Well, feel free to cite something that shows some advantage to full squats over parallel squats.
posted by electroboy at 8:53 PM on August 3

Actually the question was "Are full squats bad for the knees?" zentrification has linked to quite a few articles supporting what he, and others, have asserted. On the other hand, electroboy, all the links you've supplied have nothing to do with said question. Maybe you could supply some actual links about what is being discussed rather than random links about whether Quadriceps activation is decreased by not squatting past parallel.
posted by P.o.B. at 10:53 PM on August 3

As I said, aside from Rippetoe, Miller and Kilgore whom you criticized for lack of formal education

To be fair, electroboy said "knee injury appears to be outside of Lon Kilgore's area of specialization." Dr. Kilgore, co-author of Starting Strength, holds a masters in kinesiology and a doctorate in physiology.
posted by ludwig_van at 8:40 AM on August 4

I have grown tired of debating the formal education of a handful of the advocates of full squatting, and the cherry picking of studies to illustrate concepts that are common knowledge in discussions of squatting, such as knee forces increase with squat depth and lack of ankle flexibility causes excess stress on the hips/low back.

Limiting range of motion in injured individuals is common practice, squatting is no exception, but the goal is always to restore full range of motion when possible. Using ACL reconstruction as an example, a single leg full squat is considered the gold standard of rehab by many therapists.

There is an overwhelming consensus among leading strength coaches and researchers to the merits of full squatting vs partial range of motion squatting. No one considers full squats dangerous to the healthy knee, whether you are talking about elite powerlifting champions, such as Dr. Mario DiPasquae, Dr. Fred Hatfield, Ed Coan and Louie Simmons or researchers such as Dr. Paavo Komi, Dr. Mel C Siff, Dr. Vladimir Zatsiorsky, Dr. Stephen J Fleck and Dr. William Kraemer or dominant coaches of numerous professional teams, olympic athletes and world champions such as Poliquin, Starr, Vern Gambetta, Alan Aragon, Stuart McRobert and Charlie Francis.

All of the individuals I listed above are well versed in the literature regarding full squatting, and continue to advocate it. They also have their own unpublished data on their athletes and empirical observations to support their views; these observations should not be dismissed lightly as most of them have worked with thousands of athletes, far more data points than the small published studies we see on full squatting. As an example, Poliquin discusses implementing full squats with the canadian national ski team in this column, and his article on structural balance is instructive to the scope of data he collects.

There is enough literature to demonstrate differences between parallel and full squatting. This paper illustrates a significant difference between biceps femoris recruitment in the eccentric phase, and gluteus maximus during the eccentric and concentric phases when comparing full and parallel squatting. Squatting mechanics are are well understood, the muscles that only cross a single joint (glutes, VM, VL) act as the prime movers, while muscles that cross two joints act as stabilizers (semitedonosus, semimembrinosus, gastrocs, soleus, long head of biceps femoris). The deeper you squat, the more the hamstrings and calves are recruited to stabilize, this is well understood as the hamstring co contraction hypothesis, where the calves and hamstrings act in synergy with the ACL to prevent anterior tibial translation that quadriceps force production causes.

If you're interested in protecting your knees, particularly your ACL, full squats are of substantive benefit as they increase the strength of the hamstrings and glutes more than parallel squats, and result in more hypertrophy.
posted by zentrification at 12:19 PM on August 4

Actually the question was "Are full squats bad for the knees?"

Right, and the answer is:

No one knows, because there's not really been any research on deep squats. Some internet "experts" with dubious credentials think otherwise. On the other hand, some researchers have specifically recommended against it. Therefore, the strong reaction the OP's friends got for suggesting that parallel squats are the way to go are unwarranted, and somewhat puzzling.
posted by electroboy at 1:37 PM on August 4

Electroboy's above stated position on full squats is untenable.

"because there's not really been any research on deep squats."

Sure there is, to reiterate, in the early 60's Karl Klein studied ligament laxity in university students (control) with weight lifters who performed full squats and paratroopers who performed squat jumps (experimental). He found increased laxity of the ligaments of the knee in the weight lifters and paratroopers, and concluded squatting should be limited to parallel to avoid ligament laxity.

Meyers studied MCL instability in deep and parallel squats in 1971, and found no difference between the two. Further studies demonstrated sufficient falsification of Klein's ligament laxity hypothesis.

"Over an 8-wk training program, full or half squats did not consistently affect knee stability compared to non-squatting controls."

"This study demonstrates no significant increases in anterior-posterior tibiofemoral translation in athletes using the squat exercise as part of their off-season training program."

"In conclusion, basketball players and distance run ners experienced a transient increase in anterior and posterior laxity during exercise. Power lifters doing squats did not demonstrate a significant change in laxity."

'Some internet "experts" with dubious credentials think otherwise'

DiPasquale has an MD and was an assistant professor at University of Toronto for ten years researching athletic performance and nutrition. Komi is a full professor of neuromuscular science at University of Jyväskylä, Finland and director of the neuromuscular research center. Zatsiorsky has a PHD in biomechanics and is a full professor of kinesiology at Penn State. Kraemer has a masters in exercise physiology and PHD in physiology and biochemistry and is a professor of kinesiology, physiology and neurobiology at University of Connecticut.

Poliquin has a masters in exercise physiology, Starr was the strength coach at U Hawaii, Maryland, Hopkins, with the 70's colts who won the superbowl, gambetta accomplishments are numerous.

"On the other hand, some researchers have specifically recommended against it. "

I am unaware of any researchers who recommend against full squats in the healthy knee, aside from Klein whose views have been thoroughly disproved.

We've seen one study that concludes "To limit hip moment, the squat should not be deeper than 90° and another "squat may be more effective in muscle development but should be used cautiously in those with PCL and PF disorders, especially at greater knee flexion angles".

As hip moment and squatting with PCL and PF disorders are not the topic of discussion, this literature is insufficient evidence to claim that some researchers have specifically recommended against it.

The prevailing view in kinesiology and exercise physiology is that full squats are not dangerous to the healthy knee and may have some advantages over partial range of motion squatting.
posted by zentrification at 3:49 PM on August 4

No one knows, because there's not really been any research on deep squats. Some internet "experts" with dubious credentials think otherwise. On the other hand, some researchers have specifically recommended against it.

The bullshit meter is flying off the charts with these statements. It's obvious you don't know what you're talking about. Check on what you're talking about before making such claims.

Guess what? No one has ever tested to see if it is alright if you curl your arm past ninety degrees either.
Everybody, stop with arm curl madness!!!
posted by P.o.B. at 4:26 PM on August 4

Meyers studied MCL instability in deep and parallel squats in 1971

Unverifiable.

"Over an 8-wk training program, full or half squats did not consistently affect knee stability compared to non-squatting controls."

Shows no difference between the two. The long term study effectively eliminates any people with knee damage by only studying elite athletes.

"This study demonstrates no significant increases in anterior-posterior tibiofemoral translation in athletes using the squat exercise as part of their off-season training program."

Only examined regular squats.

"In conclusion, basketball players and distance run ners

Designed to study the difference between repetitive motion sports, like basketball and running vs. low rep high weight exercises.

DiPasquale has an MD and was an assistant professor at University of Toronto for ten years researching athletic performance and nutrition.

...and was medical director of the World Wrestling Federation. And sells quacky diet supplements.

Komi .... Zatsiorsky .... Kraemer ...

Very impressive. Did I miss where you linked to their research? Or was that in the assortment of megamass muscle get huge now links?

We've seen one study that concludes "To limit hip moment, the squat should not be deeper than 90°

Yes, that conveniently ignores the previous sentence, which states "We conclude that knee joint load can be limited by doing parallel instead of deep squats and that this will not decrease quadriceps muscle activity."

So I'll restate. Aside from some advanced novices and some self promoting supplement hucksters, there appears to be no significant demonstrated advantage to full squats over parallel squats, and no evidence that either full or parallel squats are more risky for long term knee health.
posted by electroboy at 4:30 PM on August 4

Except for the research I linked showing increased muscle mass gained on a full squat vs parallel squat program, and the research showing significant increase in hamstring and glute activation during full squatting.

Feel free to track down meyers study, or look at who references it in what context. As I stated, full squats being safe and having increased hip extensor activity is a common concept in kinesiology and exercise physiology. What's important is Kraemer, Fleck, Zatsiorsky, Komi, Hatfield, etc. don't explicitly take a position against full squatting.

How does being medical director for a large athletic group like the WWF affect DiPasquales credentials, or views on full squatting. Doctors have an ethical obligation to treat their patients regardless if the patient decides to abuse steroids. There is a lot of money in the quacky supplement business, does capitalizing on that affect his ability to make judgements on the merit of full squatting?

How do you conclude that Poliquin and Starr are advanced novices? They both have over 20 years experience training professional and olympic athletes.
posted by zentrification at 5:36 PM on August 4

Electroboy, what experience do you have with coaching and weightlifting? Just curious, as I'd like to know where you're coming from with your argument.
posted by schroedinger at 6:23 PM on August 4

Conclusion. Soccer players and weight lifters are at increased risk of developing premature knee osteoarthritis (OA). The increased risk is explained in part by knee injuries in soccer players and by high body mass in weight lifters.

I think zentrification is doing a great job of countering your arguments but seriously, you lead your list of papers on knee health with THIS? Something that shows that being heavy makes your knees more likely to be injured? I mean, seriously. No fucking shit.

You know, I was thinking about this today in karate when my sensei started talking again about bragging rights. The thing is, if you don't squat past parallel, no one gives a shit what you squat. You have no bragging rights. We can all hem and haw about how this is all about HEALTH and who cares what other people think but the truth is I would bet all of the people participating actively in this thread care at least to some degree what others think of their strength. You have yet to show us a study that it is significantly worse for the knees than squatting to parallel, and I would bet money that if you compared the proportional number of knee injuries of deep squatters to the number suffered by recreational runners you would find far, far more in the latter category. I don't believe squatting past parallel is an injury risk for most otherwise healthy people, but fuck it you know what? Every physical activity you can do is an injury risk. If you are so incredibly paranoid about your knees that you won't squat past parallel for the slight risk of hurting them, knock yourself out. But if you care at all, one smidgeon, about what other lifters think of your strength, don't even bother telling us about your parallel squat. I'm sure if you write back you will tell us all how you don't care and hey, that's cool. You don't care that we think your squat weight is meaningless, and we don't care that you believe squatting past parallel is dangerous despite absolutely no evidence to support that. Win win.
posted by ch1x0r at 8:16 PM on August 4

Yes, that conveniently ignores the previous sentence, which states "We conclude that knee joint load can be limited by doing parallel instead of deep squats and that this will not decrease quadriceps muscle activity."

Yeah, and...?

Why does the fact that knee joint load increases with flexion a point you think somehow backs up what you are saying?
Also, at some point you may realize that the squat is more than a quadriceps exercise.
posted by P.o.B. at 8:32 PM on August 4

My orthopedist said that Rippetoe and Kilgore's book was well-regarded. If you actually read the book, you'll find that it's remarkably thoughtful and thorough. There are 50 pages alone on the squat. It cover everything including where to grip the bar, how to grip the bar, where to point your eyes, etc. Every phase of the movement is explained -- why muscles are activated and why you should do it this way as opposed to another. Everything they say makes sense after you think about it. I did full squats following the book's advice for six months and had absolutely no problems.
posted by qmechanic at 4:32 AM on August 5

Evidence that compressive loading on the knee joint increases isn't evidence that full squats are harmful or detrimental to the knees. Shear forces on the collateral ligaments increase from about 30-60 degrees of knee flexion down to around parallel, but no one advocates avoiding that range of motion in the squat.
posted by zentrification at 8:29 AM on August 5