His rationale was based off sprinting, bilateral squatting (below parallel), full olympic lifts etc, and most athletic movements, where the the knee almost always goes past the toe. Achieving optimal angle of the torso to maximally stress the anterior chain is only achieved by the appropriate amount of dorsiflexion at the ankle (1). That is the point in my mind, to have a clearly defined movement that we can achieve a uniform result every time. The dorsiflexed ankle position clearly delineates itself from hinge patterns and addresses a more specific and definable position in training.
He also made the point that taking the knee to full flexion will place tension on all the ligaments (anterior, posterior, medial, lateral) and tendons (superior and inferior), while training partial range (above parallel) will actually create an overly strong muscle fiber relative to the tendon/ligament connection, which could lead to tendinopathies.(2)
Based on biomechanical calculations and measurements of cadaver knee joints, the highest retropatellar compressive forces and stresses can be seen at 90°. With increasing flexion, the wrapping effect contributes to an enhanced load distribution and enhanced force transfer with lower retropatellar compressive forces. Additionally, with further flexion of the knee joint a cranial displacement of facet contact areas with continuous enlargement of the retropatellar articulating surface occurs. Both lead to lower retropatellar compressive stresses (2).
Up to that point, I just assumed you had to keep the tibia vertical during split squats. I never questioned the logic, just assumed that was the only way to do it. I guess I just chalked it up to more experienced coaches running into issues of full ROM manifesting into a recurrence of tendinopathies. When I asked Charles about this, the response was so direct it was hard to forget “full range of motion is the best cure for tendonitis”.
The progressions laid out in some of his course work are as follows:
- Front Foot Elevated Cable Split Squat
- Cable Split Squat
- Front Foot Elevated DB Split Squat
- DB Split Squat
- BB Front Foot Elevated Split Squat
- BB Split Squat.
Of note are the cues they use: “train tracks, not tight ropes” and “down the escalator, not down the elevator”.
This is an important part of this, because when you set up with a narrow stance this challenges balance, and load and execution will be diminished. The “escalator”, a departure from the normal 90/90 in which the end point is where the back knee touches the ground transitions to the end-point being the hamstring coming in contact with the calf.
To facilitate this position; Charles would always advocate the use of Time Under Tension, specifically eccentrics. Which not only helps with conceptualizing the movement from a motor learning perspective but increases greater end range control and lowered incidence of injury (4).
It is a much more challenging movement and you find the options with increased ROM are where the challenges presents itself. This creates the great question: if there is no presence of pain why not increase range of motion? The transfer to sport or skill should be greater through better end range control. It creates a more natural limit to load from increased ROM hopefully mitigating unnecessary injury. It requires more balance and skill to execute which would also have more transference to sport then a traditional vertically oriented shin split squat.
When examining something new, one should be as non partisan as possible, but there were so many validating examples in training, which made it hard to ignore:
- Ankle mobility drills: It is contradicting to do a drill in which we are doing closed kinetic chain dorsiflexion as a movement prep drill and then tell the athlete to do the opposite in the weight room. Drawing parallels between our ankle mobility drills and using carry over as a point of reference to our split squats was a lot cleaner.
- Lunging: I think we can all agree with our lateral and posterior lateral lunges we cue “trail leg straight” with good reason. It creates a greater load on the lead leg. We don't apply this sagittal plane lunge/split squats which makes it confusing. Having a consistency in ecution of similar movements in multiple planes was a lot cleaner.
- Squatting: There is an epidemic where our squats look like hinges and our hinges look like squats. Swings are a perfect example of where people prematurely bend at the knee to accomplish the task. Simply making the clear rule of squatting - knees bend (accomplished by dorsiflexion) and hinging - hips bend (accomplished by not dorsiflexing) again, creates a cleaner, more consistent program.
- Sprint Mechanics: People who stand up prematurely tend to lack end range control in a dorsiflexed position. They simply are not strong enough to hold their bodies horizontally when the ankle is dorsiflexed. This could be from a weak posterior chain or a lack of training in that position. I personally think it is both. But I would add, it is nice to review positions in sprinting and leveraging “its like split squats in weight room”.
I look at Charles Poliquin as an incredible asset that I pulled a lot of great info from. He forced you to think, which could be due to his polarizing demeanor or he was simply right on a lot of things. Obviously pushing knees over the toes on split squats is not a one size fits all approach, if someone does have a tendinitis or a torn meniscus that would be a tough sell. But for some it might be a viable option.
To me the message was most important, not the messenger. Which is what I hope is Charles Poliquin's legacy will be.
- Fuglsang E, Telling A, Sørensen A. Effect Of Ankle Mobility And Segment Ratios On Trunk Lean In The Barbell Back Squat. The Journal Of Strength And Conditioning Research. 2017; 31(11): 3024-3033.
- Hartmann H, Wirth K, Klusemann M. Analysis Of The Load On The Knee Joint And Vertebral Column With Changes In Squatting Depth And Weight Load.Sports Med. 2013 Oct;43(10):993-1008.
- Lima Y, et al. The association of ankle dorsiflexion and dynamic knee valgus: A systematic review and meta-analysis. Physical Therapy in Sport. 2018; 29: 61-69.
- Timmins R, et al. Architectural changes of the biceps femoris after concentric or eccentric training. School of Exercise Science, Australian Catholic University, 115 Victoria Parade, Fitzroy, 16 3065, Melbourne, Victoria, Australia.