Last week we had a nice little discussion about the stresses on the knee during the deep loaded squat. At least in the research for high level olympic lifters, deep squats appear not to be as dangerous as some may think. I don’t think this means that everyone needs to go ahead and start deep squatting. I am a proponent of the deep loaded squat for some people but believe there are a lot of other considerations from a knee health perspective to think about before embarking on a long career of squat PRs and pain free knees.
1 – Mobility
Since I’m a physical therapist I decided to put this one first. After someone is not able to complete a squat adequately, the first place I look is with their mobility. The areas that are going to need some love generally when the squat is poor are:
- Ankles – Assessment / Correction
- Tibial Rotation
- Hip Mobility
2 – Patellar Tracking
I’m sure we’ve all heard of and are sick of the old knees out cue. The major reason for this is the goal of getting the knee to track over top of the toes during the squat. I like to think of the patella as a train that rides along a train track known as the trochlear groove of the femur (picture). As we squat, if the knees aren’t directly over the toes we may be getting the train not tracking along the tracks and getting some abnormal wear of the patello-femoral joint. As discussed above, if we have some mobility issues, particularly in hip and tibial rotation as well as ankle dorsiflexion then we’re going to create a tracking issue. Obviously if we’re in the business of keeping our knees healthy then we’re going to really care about this variable.
3 – Motor Control, Strength and Stability of the Core, Foot, and Hip
When it comes to proper patellar tracking along the trochlear groove we not only need to have adequate mobility, but also strength and stability. Stability issues of the core, hips, and foot can all lead to tracking issues at the knee, thereby increasing knee stress. Click HERE for more info about why this happens.
4 – Technique
Technique is arguably the most important aspect of all of these finer points discussed for knee health in the squat. The only reason I didn’t put it first is because we need points 1-3 in alignment and up to snuff in order to complete deep squats properly. Squat technique could be a whole article series in itself so I won’t go into depth here but there are some points I’d like to go over in the squat that directly affect knee health
- The further your knees come forward in the squat the greater the shear forces become in the knee. Having the knees back more in the squat will decrease these forces. However, pushing the knees back will increase shear forces on the spine. It’s a catch-22 that we’ll discuss more in depth in the next article. Also keep in mind that to adequately complete olympic lift variations like the clean and snatch we’ll need to adopt a more upright torso that will in turn force the knees forward further and increase shear force on the knees.
- Faster lowering into the bottom of the squat and subsequent reversal of movement places more compressive and shear forces on the knee. It’s no wonder that more knee injuries are reported in the catch position of the clean and snatch where athletes are dropping very quickly into the bottom position of a deep squat. Decreased speed into the bottom of the squat improves this stress.
- Fatigue changes kinematics. As athletes fatigue in the squat they generally have less control at the bottom of the squat (Increased knee stress) and increased trunk forward pitch (Decreased knee stress but increased spinal shear stress)
This information gives us a little additional information on how to either increase or decrease stress on the knee. Just keep in mind that you’ve got a catch-22 on your hands as modifying position can also increase stress elsewhere.
5 – Quad Strength
Early in my career I neglected the quadriceps some in my discussions in knee health. Honestly, it wasn’t as sexy or novel as discussing regional interdependence. In reality though, the quadriceps attach to the patella and have a direct relationship to both patellar tracking and controlling shear forces in the knee. As discussed above and in prior articles, the knee takes increasing posterior shear forces in the squat maximizing around 90 degrees and increasing with fast speed of execution into the bottom of the squat. A strong quadricep will help to buffer this and prevent as much stress on the knee.
My favorite quad exercises as of late have been lunge and split squat variations. While attempting to maximize quadriceps activity and prepare for the squat I like to keep the step relatively short to mimic the mechanics of upright squatting. Another favorite of mine is to elevate the front foot to increase knee flexion and more closely mimic the deep squat knee mechanics. These are also great for improving asymmetries from side to side.
https://youtu.be/y5DP3ustMYU
6 – Preparation, proper progression and volume management for deep squatting
Having been reading more of William Gabbet’s research lately about volume management and injury I think that a lot of the principles apply to squatting as well. Squats need to be slowly incorporated into a comprehensive strength and conditioning program with adequate thought toward total knee stress throughout the training, week, month and year. Doing too much too soon without much thought toward the total program’s stress on the athlete can leave your athlete with sore and painful knees.
I can’t tell you how often I have athletes who start having knee pain after starting a high volume olympic lifting program or after workouts with very high squat volume (Karen anyone?) Any sudden changes in training volume can cause issues. If you’re an athlete who needs to be able to handle high training volumes of squatting make sure you work your way slowly toward your goals.
7 – Exercise Variety
Paul Chek was the first one to introduce me to the concept of pattern overload. The concept is that if we are constantly wearing the body in a consistent way, then we are more susceptible to overuse injuries and degenerative changes in a predictive way.
Finding the ideal squat stance for the individual is going to be incredibly important for health of not only the knees, but spine and hips as well. Despite this being important, it’s also valuable to consistently modify the way you perform squats.
This is a catch-22 situation as well. Given that if we change exercises too frequently and without preparation for the next exercise we might be exposing ourselves to injury and not giving our bodies adequate time to adapt to the stresses of training. We can’t get too wild with exercise variations. Moderation may be prudent here.
Some variety you can try throughout the course of the year would be:
- Vary stance used in the squat
- Vary bar position and torso inclination (high vs. low bar back squat, front vs. overhead vs. zercher)
- Vary bar types (Safety Squat, Camber, Buffalo)
- Vary Tempo (Slower eccentrics, pausing at the bottom of the lift)
- Vary Depth (Powerlifting style breaking parallel, olympic lifting maximal depth, box squatting variations
- Vary the movement – Utilizing more single leg variations like squats, lunges, split squats and step-ups can help minimize pattern overuse and break up the monotony of training. I personally take several months off per year from squatting for a mental and physical break from the movement.
Finally, some considerations of when it might not be safe to squat?
- Current knee pain – If you’ve got knee pain then get yourself checked out before attempting any squatting program
- Pathology in the knee – advanced arthritis, meniscus injury, ligamentous injury (ACL and PCL especially). Again see a professional first.
- Poor mobility – Having mobility problems will almost certainly lead to compensatory movement and increased stress in areas you probably don’t want it. Find someone to help you out in this regard as well.
- No access to coaching – I know there are plenty of do it yourselfers out there but nothing will beat expert coaching on how to perform this lift properly. If you don’t have experience with this lift then do yourself a favor and find a qualified coach to help you.
Hopefully this article shed some light on what should be in order to have someone squat proficiently and safely. The stress on the knee will be minimized if we take these factors into consideration. Next article we’ll talk spinal safety in the squat. Given how common low back pain is, it should be a good one.
My knees hurt from sitting so long to write this,
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Bibliography:
- 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 Med.
- Reinold, M. (2009, May 11). Solving the Patellofemoral Mystery. Retrieved January 10, 2016, from http://www.mikereinold.com/2009/05/solving-patellofemoral-mystery.html