Last week's blog delved into ways to manage and ultimately overcome patellofemoral pain (PFP). Moving, loading, and continuing with your normal day to day can be frustrating and tricky when anterior knee pain is limiting.
Patellofemoral pain often manifests with positional intolerance (ie: “I can all the way but it only hurts during this [mid range knee flexion] part”), as well as load intolerance (ie: “I can back squat with ___ lbs/kgs, but my knee (s) hurts once I to ___lbs/kgs”). Thus, a big point we preach is that it there is often a threshold of tolerance we are dealing with, and that it is not the activity (squatting) itself that is “bad for your knees.”
Two common lower body strength exercises used throughout a knee rehab program at Made 2 Move are the lunge and split squat- Nothing fancy or special. But what’s the difference between the two? When are each warranted? How can I progress them to be more sport specific or regress them to work around knee pain? Let’s jump in.
The Lunge
Can perform in multiple planes
Forward
Reverse
Lateral
Can be made sport specific
Falling lunges
Simulates speed and forces experienced when sprinting and decelerating
The Split Squat (SS)
Can typically load heavier
More stable position
Can elevate the heel on a plate to progress the movement (this one is great for foot strength too!)
Static foot placement often makes it simpler to standardize ROM and loading with each rep
With both the split squat and the lunge, you can similarly adjust the speed of the movement and the external load/implement applied. External load refers to any additional weight added to make the movement more challenging. Think: dumbbells or KBs in front rack, at the side, or overhead (this one is spicy and requires adequate shoulder and thoracic mobility). A safety bar could also be used for more stability and loading with the split squat. And of course, a barbell can be used, which requires more stability than DBs or the safety bar, and can be placed in the front or back rack for both the lunge or split squat.
What Does The Research Say?
A 2022 research article looked at the differences that a 10 cm step (think the height of a plate) and direction of lunge (forward vs. lateral) has on PF compressive stress and force experienced at the knee. Researchers noted that, “Patellofemoral joint loading changed according to lunge type, step height, and knee angle” (Escamilla et al. 2022).
In a nutshell, researchers found that there were higher amounts of compressive forces and stress experienced at the PFJ with
Shallower knee angles in the forward lunge
Deeper knee angles with a the lateral lunge
Mid-range knee angles when lunging on the ground vs. elevating the front foot just 10 cm (Escamilla et al. 2022).
The above research gives us insight into ways we can modify lunging to accommodate knee pain. Early questions we can ask ourselves when deciding how to load our lunges around knee pain…
Can we adjust range of motion (knee angles)?
Can we elevate the front foot to minimize stress on the PFJ?
Can we play around with forward vs. lateral lunges to figure out which one is more tolerable?
So we can play with ROM, direction of lunge, AND step height to tweak load at the knee throughout rehab! Lots of ways to modify!
Another research article looked at 20 females and found that the backward lunge had less PFJ loading than the forward lunge (Goulette et al. 2020).
And for split squats? A 2023 article looked at the effect of foot placement (ie how far apart your feet are) on PFJ loading during the split squat. As the step length increases (the farther out you put that front foot when you set up), the less ROM you move through at the knee. This minor adjustment in increasing step length also shifted more of the work to the hip extensors (glutes and hamstrings) rather than the knee extensors (quads). This is important as it gives us a very simple way to play with both ROM and loading profiles in order to modify.
Interestingly researchers noted that “The optimal step length for strength training in healthy adults appears to be more suitable when it is equal to the length of the individual lower extremity” (Qingquan 2023). (Hint, Hint- our therapists have a few tricks up our sleeves to help you quickly and easily find this “optimal step length” with common exercises).
A lot of these modifications are pretty inuitive and something most athletes figure out and tweak naturally at the gym. However, coming up with a structured plan, albeit consisting of some trial and error, with your Made 2 Move PT can minimize some of the frustration that accompanies knee pain in athletes.
In summary…
A few ways we can modify our lunges or split squats to work around knee pain:
Adjust the distance between the feet
Placing the front foot farther from the back foot lessens the load on the anterior knee and shifts the load more to the posterior musculature (glutes and hamstrings).
Adjust knee angle (find what’s tolerable and gradually progress).
Adjust step height
The 2022 article above looked at the differences in PF joint stress just by adjusting the step height of the forward foot to a 10 cm plate (Escamilla et al. 2022). Even that tiny adjustment decreased load on the front knee, a great starting point if anterior knee pain is limiting your ability to lunge.
Adjust plane of movement
Reverse, forward, or lateral!
All of these modifications likely will be combined and used throughout the rehab process. And taken with you back into the gym when PT is over! Interested in working with a PT who won’t just tell you to stop doing the exercise that hurts you but rather will help you figure out why it’s happening and how to get back to doing these movements comfortably? Reach out to frontdesk@made2movept.com today to set up an initial consultation!
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