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. If you want to keep your knees healthy, this is a must!
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.
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 in order to complete deep squats properly and efficiently. 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 another time.
- Faster lowering into the bottom of the squat and subsequent reversal of movement places more compressive and shear forces on the knee. 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 – Quadricep Strength
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.
The quad exercisesI like to prescibe are 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.